| Message ID | 0aca6daf-356a-7b03-c007-e33c35114356@codesourcery.com |
|---|---|
| State | New |
| Headers | show |
| Series | [WIP] Re: [PATCH] openmp: Fix intermittent hanging of task-detach-6 libgomp tests [PR98738] | expand |
On Fri, Feb 19, 2021 at 07:12:42PM +0000, Kwok Cheung Yeung wrote: > I have opted for a union of completion_sem (for tasks that are undeferred) > and a struct gomp_team *detach_team (for deferred tasks) that holds the team > if the completion event has not yet fulfilled, or NULL if is it. I don't see > the point of having an indirection to the union here since the union is just > the size of a pointer, so it might as well be inlined. I see three issues with the union of completion_sem and detach_team done that way. 1) while linux --enable-futex and accel gomp_sem_t is small (int), rtems and especially posix gomp_sem_t is large; so while it might be a good idea to inline gomp_sem_t on config/{linux,accel} into the union, for the rest it might be better to use indirection; if it is only for the undeferred tasks, it could be just using an automatic variable and put into the struct address of that; could be done either always, or define some macro in config/{linux,accel}/sem.h that gomp_sem_t is small and decide on the indirection based on that macro 2) kind == GOMP_TASK_UNDEFERRED is true also for the deferred tasks while running the cpyfn callback; guess this could be dealt with making sure the detach handling is done only after thr->task = task; if (cpyfn) { cpyfn (arg, data); task->copy_ctors_done = true; } else memcpy (arg, data, arg_size); thr->task = parent; task->kind = GOMP_TASK_WAITING; task->fn = fn; task->fn_data = arg; task->final_task = (flags & GOMP_TASK_FLAG_FINAL) >> 1; I see you've instead removed the GOMP_TASK_UNDEFERRED but the rationale for that is that the copy constructors are being run synchronously 3) kind is not constant, for the deferred tasks it can change over the lifetime of the task, as you've said in the comments, it is kind == GOMP_TASK_UNDEFERRED vs. other values; while the changes of task->kind are done while holding the task lock, omp_fulfill_event reads it before locking that lock, so I think it needs to be done using if (__atomic_load_n (&task->kind, MEMMODEL_RELAXED) == GOMP_TASK_UNDEFERRED) Pedantically the stores to task->kind also need to be done with __atomic_store_n MEMMODEL_RELAXED. Now, similarly for 3) on task->kind, task->detach_team is similar case, again, some other omp_fulfill_event can clear it (under lock, but still read outside of the lock), so it probably should be read with struct gomp_team *team = __atomic_load_n (&task->detach_team, MEMMODEL_RELAXED); And again, pedantically the detach_team stores should be atomic relaxed stores too. > > Do you agree with this, or see some reason why this can't work? > > The main problem I see is this code in gomp_barrier_handle_tasks: > > if (--team->task_count == 0 > && gomp_team_barrier_waiting_for_tasks (&team->barrier)) > { > gomp_team_barrier_done (&team->barrier, state); > > We do not have access to state from within omp_fulfill_event, so how should > this be handled? Sure, omp_fulfill_event shouldn't do any waiting, it needs to awake anything that could have been waiting. > @@ -688,8 +697,7 @@ struct gomp_team > int work_share_cancelled; > int team_cancelled; > > - /* Tasks waiting for their completion event to be fulfilled. */ > - struct priority_queue task_detach_queue; > + /* Number of tasks waiting for their completion event to be fulfilled. */ > unsigned int task_detach_count; Do we need task_detach_count? Currently it is only initialized and incremented/decremented, but never tested for anything. Though see below. > + gomp_debug (0, "omp_fulfill_event: %p event fulfilled for finished task\n", > + task); > + size_t new_tasks = gomp_task_run_post_handle_depend (task, team); > + gomp_task_run_post_remove_parent (task); > + gomp_clear_parent (&task->children_queue); > + gomp_task_run_post_remove_taskgroup (task); > + team->task_count--; > + team->task_detach_count--; > + > + /* Wake up any threads that may be waiting for the detached task > + to complete. */ > + struct gomp_task *parent = task->parent; > + > + if (parent && parent->taskwait) > + { > + if (parent->taskwait->in_taskwait) > + { > + parent->taskwait->in_taskwait = false; > + gomp_sem_post (&parent->taskwait->taskwait_sem); > + } > + else if (parent->taskwait->in_depend_wait) > + { > + parent->taskwait->in_depend_wait = false; > + gomp_sem_post (&parent->taskwait->taskwait_sem); > + } > + } Looking at gomp_task_run_post_remove_parent, doesn't that function already handle the in_taskwait and in_depend_wait gomp_sem_posts? > + if (task->taskgroup && task->taskgroup->in_taskgroup_wait) > + { > + task->taskgroup->in_taskgroup_wait = false; > + gomp_sem_post (&task->taskgroup->taskgroup_sem); > + } And into gomp_task_run_post_remove_taskgroup, doesn't that already handle the in_taskgroup_wait gomp_sem_post? > + > + int do_wake = 0; > + if (new_tasks > 1) > + { > + do_wake = team->nthreads - team->task_running_count; > + if (do_wake > new_tasks) > + do_wake = new_tasks; > + } > + > + gomp_mutex_unlock (&team->task_lock); > + if (do_wake) > + gomp_team_barrier_wake (&team->barrier, do_wake); I think for the barrier case we need to make a difference between team == gomp_thread ()->ts.team case (I guess the more usual one), where the fact that we know some thread (the one calling omp_fulfill_event) is provably doing something other than sitting on a barrier waiting for tasks means it is much simpler, i.e. that gomp_team_barrier_set_task_pending (&team->barrier); is needed only when some tasks dependent on completion of the current one were added to the queues, but gomp_task_run_post_handle_depend -> gomp_task_run_post_handle_dependers takes care of that call and the above do_wake handles that too, though the exact details I think need fixing - in gomp_barrier_handle_tasks the reason for if (new_tasks > 1) is that if there is a single dependent task, the current thread just finished handling one task and so can take that single task and so no need to wake up. While in the omp_fulfill_event case, even if there is just one new task, we need to schedule it to some thread and so is desirable to wake some thread. All we know (if team == gomp_thread ()->ts.team) is that at least one thread is doing something else but that one could be busy for quite some time. And the other case is the omp_fulfill_event call from unshackeled thread, i.e. team != gomp_thread ()->ts.team. Here, e.g. what gomp_target_task_completion talks about applies: /* I'm afraid this can't be done after releasing team->task_lock, as gomp_target_task_completion is run from unrelated thread and therefore in between gomp_mutex_unlock and gomp_team_barrier_wake the team could be gone already. */ Even there are 2 different cases. One is where team->task_running_count > 0, at that point we know at least one task is running and so the only thing that is unsafe gomp_team_barrier_wake (&team->barrier, do_wake); after gomp_mutex_unlock (&team->task_lock); - there is a possibility that in between the two calls the thread running omp_fulfill_event gets interrupted or just delayed and the team finishes barrier and is freed too. So the gomp_team_barrier_wake needs to be done before the unlock in that case. And then there is the case where all tasks finish on a barrier but some haven't been fulfilled yet. In that case, when the last thread calls gomp_team_barrier_wait_end we run in there: if (__builtin_expect (state & BAR_WAS_LAST, 0)) ... if (__builtin_expect (team->task_count, 0)) { gomp_barrier_handle_tasks (state); state &= ~BAR_WAS_LAST; } and gomp_barrier_handle_tasks it will hit the gomp_mutex_lock (&team->task_lock); if (gomp_barrier_last_thread (state)) { if (team->task_count == 0) { gomp_team_barrier_done (&team->barrier, state); gomp_mutex_unlock (&team->task_lock); gomp_team_barrier_wake (&team->barrier, 0); return; } gomp_team_barrier_set_waiting_for_tasks (&team->barrier); } but team->task_count is not 0 (because of the one or more non-fulfilled tasks), priority_queue_empty_p is true and so after unlocking the function will just return. And then it will jump to do_wait and on wake ups do gomp_barrier_handle_tasks again. So, I think for the team != gomp_thread ()->ts.team && !do_wake && gomp_team_barrier_waiting_for_tasks (&team->barrier) && team->task_detach_count == 0 case, we need to wake up 1 thread anyway and arrange for it to do: gomp_team_barrier_done (&team->barrier, state); gomp_mutex_unlock (&team->task_lock); gomp_team_barrier_wake (&team->barrier, 0); Possibly in if (!priority_queue_empty_p (&team->task_queue, MEMMODEL_RELAXED)) add else if (team->task_count == 0 && gomp_team_barrier_waiting_for_tasks (&team->barrier)) { gomp_team_barrier_done (&team->barrier, state); gomp_mutex_unlock (&team->task_lock); gomp_team_barrier_wake (&team->barrier, 0); if (to_free) { gomp_finish_task (to_free); free (to_free); } return; } but the: if (--team->task_count == 0 && gomp_team_barrier_waiting_for_tasks (&team->barrier)) { gomp_team_barrier_done (&team->barrier, state); gomp_mutex_unlock (&team->task_lock); gomp_team_barrier_wake (&team->barrier, 0); gomp_mutex_lock (&team->task_lock); } in that case would then be incorrect, we don't want to do that twice. So, either that second if would need to do the to_free handling and return instead of taking the lock again and looping, or perhaps we can just do --team->task_count; there instead and let the above added else if handle that? Jakub
On Mon, Feb 22, 2021 at 02:49:44PM +0100, Jakub Jelinek wrote: > So, I think for the team != gomp_thread ()->ts.team > && !do_wake > && gomp_team_barrier_waiting_for_tasks (&team->barrier) > && team->task_detach_count == 0 > case, we need to wake up 1 thread anyway and arrange for it to do: > gomp_team_barrier_done (&team->barrier, state); > gomp_mutex_unlock (&team->task_lock); > gomp_team_barrier_wake (&team->barrier, 0); > Possibly in > if (!priority_queue_empty_p (&team->task_queue, MEMMODEL_RELAXED)) > add > else if (team->task_count == 0 > && gomp_team_barrier_waiting_for_tasks (&team->barrier)) > { > gomp_team_barrier_done (&team->barrier, state); > gomp_mutex_unlock (&team->task_lock); > gomp_team_barrier_wake (&team->barrier, 0); > if (to_free) > { > gomp_finish_task (to_free); > free (to_free); > } > return; > } > but the: > if (--team->task_count == 0 > && gomp_team_barrier_waiting_for_tasks (&team->barrier)) > { > gomp_team_barrier_done (&team->barrier, state); > gomp_mutex_unlock (&team->task_lock); > gomp_team_barrier_wake (&team->barrier, 0); > gomp_mutex_lock (&team->task_lock); > } > in that case would then be incorrect, we don't want to do that twice. > So, either that second if would need to do the to_free handling > and return instead of taking the lock again and looping, or > perhaps we can just do > --team->task_count; > there instead and let the above added else if handle that? FYI, I've just tested that part of change alone whether it doesn't break anything else and it worked fine: diff --git a/libgomp/task.c b/libgomp/task.c index b242e7c8d20..9c27c3b5148 100644 --- a/libgomp/task.c +++ b/libgomp/task.c @@ -1405,6 +1405,19 @@ gomp_barrier_handle_tasks (gomp_barrier_state_t state) team->task_running_count++; child_task->in_tied_task = true; } + else if (team->task_count == 0 + && gomp_team_barrier_waiting_for_tasks (&team->barrier)) + { + gomp_team_barrier_done (&team->barrier, state); + gomp_mutex_unlock (&team->task_lock); + gomp_team_barrier_wake (&team->barrier, 0); + if (to_free) + { + gomp_finish_task (to_free); + free (to_free); + } + return; + } gomp_mutex_unlock (&team->task_lock); if (do_wake) { @@ -1479,14 +1492,7 @@ gomp_barrier_handle_tasks (gomp_barrier_state_t state) if (do_wake > new_tasks) do_wake = new_tasks; } - if (--team->task_count == 0 - && gomp_team_barrier_waiting_for_tasks (&team->barrier)) - { - gomp_team_barrier_done (&team->barrier, state); - gomp_mutex_unlock (&team->task_lock); - gomp_team_barrier_wake (&team->barrier, 0); - gomp_mutex_lock (&team->task_lock); - } + --team->task_count; } } } Jakub
On 19/02/2021 7:12 pm, Kwok Cheung Yeung wrote: > I have included the current state of my patch. All task-detach-* tests pass when > executed without offloading or with offloading to GCN, but with offloading to > Nvidia, task-detach-6.* hangs consistently but everything else passes (probably > because of the missing gomp_team_barrier_done?). > It looks like the hang has nothing to do with the detach patch - this hangs consistently for me when offloaded to NVPTX: #include <omp.h> int main (void) { #pragma omp target #pragma omp parallel #pragma omp task ; } This doesn't hang when offloaded to GCN or the host device, or if num_threads(1) is specified on the omp parallel. Kwok
On Tue, Feb 23, 2021 at 09:43:51PM +0000, Kwok Cheung Yeung wrote: > On 19/02/2021 7:12 pm, Kwok Cheung Yeung wrote: > > I have included the current state of my patch. All task-detach-* tests > > pass when executed without offloading or with offloading to GCN, but > > with offloading to Nvidia, task-detach-6.* hangs consistently but > > everything else passes (probably because of the missing > > gomp_team_barrier_done?). > > > > It looks like the hang has nothing to do with the detach patch - this hangs > consistently for me when offloaded to NVPTX: > > #include <omp.h> > > int main (void) > { > #pragma omp target > #pragma omp parallel > #pragma omp task > ; > } > > This doesn't hang when offloaded to GCN or the host device, or if > num_threads(1) is specified on the omp parallel. Then it can be solved separately, I'll try to have a look if I see something bad from the dumps, but I admit I don't have much experience with debugging NVPTX offloaded code... Jakub
On 22/02/2021 1:49 pm, Jakub Jelinek wrote: > I see three issues with the union of completion_sem and detach_team done > that way. > > 1) while linux --enable-futex and accel gomp_sem_t is small (int), rtems > and especially posix gomp_sem_t is large; so while it might be a good > idea to inline gomp_sem_t on config/{linux,accel} into the union, for > the rest it might be better to use indirection; if it is only for the > undeferred tasks, it could be just using an automatic variable and > put into the struct address of that; could be done either always, > or define some macro in config/{linux,accel}/sem.h that gomp_sem_t is > small and decide on the indirection based on that macro I think a pointer to an automatic variable would be simplest. > 2) kind == GOMP_TASK_UNDEFERRED is true also for the deferred tasks while > running the cpyfn callback; guess this could be dealt with making sure > the detach handling is done only after > thr->task = task; > if (cpyfn) > { > cpyfn (arg, data); > task->copy_ctors_done = true; > } > else > memcpy (arg, data, arg_size); > thr->task = parent; > task->kind = GOMP_TASK_WAITING; > task->fn = fn; > task->fn_data = arg; > task->final_task = (flags & GOMP_TASK_FLAG_FINAL) >> 1; > I see you've instead removed the GOMP_TASK_UNDEFERRED but the rationale > for that is that the copy constructors are being run synchronously Can anything in cpyfn make use of the fact that kind==GOMP_TASK_UNDEFERRED while executing it? Anyway, if we want to keep this, then I suppose we could just add an extra field deferred_p that does not change for the lifetime of the task to indicate that the task is 'really' a deferred task. > 3) kind is not constant, for the deferred tasks it can change over the > lifetime of the task, as you've said in the comments, it is kind == > GOMP_TASK_UNDEFERRED vs. other values; while the changes of task->kind > are done while holding the task lock, omp_fulfill_event reads it before > locking that lock, so I think it needs to be done using > if (__atomic_load_n (&task->kind, MEMMODEL_RELAXED) == GOMP_TASK_UNDEFERRED) > Pedantically the stores to task->kind also need to be done > with __atomic_store_n MEMMODEL_RELAXED. If we check task->deferred_p instead (which never changes for a task after instantiation), is that still necessary? > Now, similarly for 3) on task->kind, task->detach_team is similar case, > again, some other omp_fulfill_event can clear it (under lock, but still read > outside of the lock), so it > probably should be read with > struct gomp_team *team > = __atomic_load_n (&task->detach_team, MEMMODEL_RELAXED); > And again, pedantically the detach_team stores should be atomic relaxed > stores too. > Done. > Looking at gomp_task_run_post_remove_parent, doesn't that function > already handle the in_taskwait and in_depend_wait gomp_sem_posts? > And into gomp_task_run_post_remove_taskgroup, doesn't that already > handle the in_taskgroup_wait gomp_sem_post? The extra code has been removed. > - in gomp_barrier_handle_tasks the reason for if (new_tasks > 1) > is that if there is a single dependent task, the current thread > just finished handling one task and so can take that single task and so no > need to wake up. While in the omp_fulfill_event case, even if there > is just one new task, we need to schedule it to some thread and so > is desirable to wake some thread. In that case, we could just do 'if (new_tasks > 0)' instead? > All we know > (if team == gomp_thread ()->ts.team) is that at least one thread is doing > something else but that one could be busy for quite some time. Well, it should still get around to the new task eventually, so there is no problem in terms of correctness here. I suppose we could always wake up one more thread than strictly necessary, but that might have knock-on effects on performance elsewhere? > And the other case is the omp_fulfill_event call from unshackeled thread, > i.e. team != gomp_thread ()->ts.team. > Here, e.g. what gomp_target_task_completion talks about applies: > /* I'm afraid this can't be done after releasing team->task_lock, > as gomp_target_task_completion is run from unrelated thread and > therefore in between gomp_mutex_unlock and gomp_team_barrier_wake > the team could be gone already. */ > Even there are 2 different cases. > One is where team->task_running_count > 0, at that point we know > at least one task is running and so the only thing that is unsafe > gomp_team_barrier_wake (&team->barrier, do_wake); > after gomp_mutex_unlock (&team->task_lock); - there is a possibility > that in between the two calls the thread running omp_fulfill_event > gets interrupted or just delayed and the team finishes barrier and > is freed too. So the gomp_team_barrier_wake needs to be done before > the unlock in that case. The lock is now freed after the call for unshackeled threads, before otherwise. > And then there is the case where all tasks finish on a barrier but some > haven't been fulfilled yet. > In that case, when the last thread calls ... > So, I think for the team != gomp_thread ()->ts.team > && !do_wake > && gomp_team_barrier_waiting_for_tasks (&team->barrier) > && team->task_detach_count == 0 > case, we need to wake up 1 thread anyway and arrange for it to do: > gomp_team_barrier_done (&team->barrier, state); > gomp_mutex_unlock (&team->task_lock); > gomp_team_barrier_wake (&team->barrier, 0); > Possibly in > if (!priority_queue_empty_p (&team->task_queue, MEMMODEL_RELAXED)) > add > else if (team->task_count == 0 > && gomp_team_barrier_waiting_for_tasks (&team->barrier)) > { > gomp_team_barrier_done (&team->barrier, state); > gomp_mutex_unlock (&team->task_lock); > gomp_team_barrier_wake (&team->barrier, 0); > if (to_free) > { > gomp_finish_task (to_free); > free (to_free); > } > return; > } > but the: > if (--team->task_count == 0 > && gomp_team_barrier_waiting_for_tasks (&team->barrier)) > { > gomp_team_barrier_done (&team->barrier, state); > gomp_mutex_unlock (&team->task_lock); > gomp_team_barrier_wake (&team->barrier, 0); > gomp_mutex_lock (&team->task_lock); > } > in that case would then be incorrect, we don't want to do that twice. > So, either that second if would need to do the to_free handling > and return instead of taking the lock again and looping, or > perhaps we can just do > --team->task_count; > there instead and let the above added else if handle that? > I have applied your patch to move the gomp_team_barrier_done, and in omp_fulfill_event, I ensure that a single thread is woken up so that gomp_barrier_handle_tasks can signal for the barrier to finish. I'm having some trouble coming up with a testcase to test this scenario though. I tried having a testcase like this to have threads in separate teams: #pragma omp teams num_teams (2) shared (event, started) #pragma omp parallel num_threads (1) if (omp_get_team_num () == 0) { #pragma omp task detach (event) started = 1; } else // Wait for started to become 1 omp_fulfill_event (event); but it does not work because GOMP_teams_reg launches the enclosed block sequentially: for (gomp_team_num = 0; gomp_team_num < num_teams; gomp_team_num++) fn (data); and when the first team launches, it blocks waiting for the detach event in GOMP_parallel_end->gomp_team_end->gomp_team_barrier_wait_end, and never gets around to launching the second team. If I omit the 'omp parallel' (to try to get an undeferred task), GCC refuses to compile (only 'distribute', 'parallel' or 'loop' regions are allowed to be strictly nested inside 'teams' region). And you can't nest 'omp teams' inside an 'omp parallel' either. Is there any way of doing this within OpenMP or do we have to resort to creating threads outside of OpenMP? Thanks Kwok From 0fa4deb89f3778ccacd64b01de377ba2b7879db1 Mon Sep 17 00:00:00 2001 From: Kwok Cheung Yeung <kcy@codesourcery.com> Date: Thu, 21 Jan 2021 05:38:47 -0800 Subject: [PATCH] openmp: Fix intermittent hanging of task-detach-6 libgomp tests [PR98738] This adds support for the task detach clause to taskwait and taskgroup, and simplifies the handling of the detach clause by moving most of the extra handling required for detach tasks to omp_fulfill_event. 2021-02-24 Kwok Cheung Yeung <kcy@codesourcery.com> Jakub Jelinek <jakub@redhat.com> libgomp/ PR libgomp/98738 * libgomp.h (enum gomp_task_kind): Add GOMP_TASK_DETACHED. (struct gomp_task): Replace detach and completion_sem fields with union containing completion_sem and detach_team. Add deferred_p field. (struct gomp_team): Remove task_detach_queue. * task.c: Include assert.h. (gomp_init_task): Initialize deferred_p and detach_team fields. (task_fulfilled_p): Delete. (GOMP_task): Use address of task as the event handle. Remove initialization of detach field. Initialize deferred_p field. Use automatic local for completion_sem. Initialize detach_team field for deferred tasks. (gomp_barrier_handle_tasks): Remove handling of task_detach_queue. Set kind of suspended detach task to GOMP_TASK_DETACHED and decrement task_running_count. Move finish_cancelled block out of else branch. Relocate call to gomp_team_barrier_done. (GOMP_taskwait): Handle tasks with completion events that have not been fulfilled. (GOMP_taskgroup_end): Likewise. (omp_fulfill_event): Use address of task as event handle. Post to completion_sem for undeferred tasks. Clear detach_team if task has not finished. For finished tasks, handle post-execution tasks, call gomp_team_barrier_wake if necessary, and free task. * team.c (gomp_new_team): Remove initialization of task_detach_queue. (free_team): Remove free of task_detach_queue. * testsuite/libgomp.c-c++-common/task-detach-1.c: Fix formatting. * testsuite/libgomp.c-c++-common/task-detach-2.c: Fix formatting. * testsuite/libgomp.c-c++-common/task-detach-3.c: Fix formatting. * testsuite/libgomp.c-c++-common/task-detach-4.c: Fix formatting. * testsuite/libgomp.c-c++-common/task-detach-5.c: Fix formatting. Change data-sharing of detach events on enclosing parallel to private. * testsuite/libgomp.c-c++-common/task-detach-6.c: Likewise. Remove taskwait directive. * testsuite/libgomp.c-c++-common/task-detach-7.c: New. * testsuite/libgomp.c-c++-common/task-detach-8.c: New. * testsuite/libgomp.c-c++-common/task-detach-9.c: New. * testsuite/libgomp.c-c++-common/task-detach-10.c: New. * testsuite/libgomp.c-c++-common/task-detach-11.c: New. * testsuite/libgomp.c-c++-common/task-detach-1.f90: Fix formatting. * testsuite/libgomp.c-c++-common/task-detach-2.f90: Fix formatting. * testsuite/libgomp.c-c++-common/task-detach-3.f90: Fix formatting. * testsuite/libgomp.c-c++-common/task-detach-4.f90: Fix formatting. * testsuite/libgomp.fortran/task-detach-5.f90: Fix formatting. Change data-sharing of detach events on enclosing parallel to private. * testsuite/libgomp.fortran/task-detach-6.f90: Likewise. Remove taskwait directive. * testsuite/libgomp.c-c++-common/task-detach-7.f90: New. * testsuite/libgomp.c-c++-common/task-detach-8.f90: New. * testsuite/libgomp.c-c++-common/task-detach-9.f90: New. * testsuite/libgomp.c-c++-common/task-detach-10.f90: New. * testsuite/libgomp.c-c++-common/task-detach-11.f90: New. --- libgomp/libgomp.h | 19 +- libgomp/task.c | 236 ++++++++++++++------- libgomp/team.c | 2 - .../testsuite/libgomp.c-c++-common/task-detach-1.c | 4 +- .../libgomp.c-c++-common/task-detach-10.c | 45 ++++ .../libgomp.c-c++-common/task-detach-11.c | 13 ++ .../testsuite/libgomp.c-c++-common/task-detach-2.c | 6 +- .../testsuite/libgomp.c-c++-common/task-detach-3.c | 6 +- .../testsuite/libgomp.c-c++-common/task-detach-4.c | 4 +- .../testsuite/libgomp.c-c++-common/task-detach-5.c | 8 +- .../testsuite/libgomp.c-c++-common/task-detach-6.c | 8 +- .../testsuite/libgomp.c-c++-common/task-detach-7.c | 45 ++++ .../testsuite/libgomp.c-c++-common/task-detach-8.c | 47 ++++ .../testsuite/libgomp.c-c++-common/task-detach-9.c | 43 ++++ .../testsuite/libgomp.fortran/task-detach-1.f90 | 4 +- .../testsuite/libgomp.fortran/task-detach-10.f90 | 44 ++++ .../testsuite/libgomp.fortran/task-detach-11.f90 | 13 ++ .../testsuite/libgomp.fortran/task-detach-2.f90 | 6 +- .../testsuite/libgomp.fortran/task-detach-3.f90 | 6 +- .../testsuite/libgomp.fortran/task-detach-4.f90 | 4 +- .../testsuite/libgomp.fortran/task-detach-5.f90 | 8 +- .../testsuite/libgomp.fortran/task-detach-6.f90 | 16 +- .../testsuite/libgomp.fortran/task-detach-7.f90 | 42 ++++ .../testsuite/libgomp.fortran/task-detach-8.f90 | 45 ++++ .../testsuite/libgomp.fortran/task-detach-9.f90 | 41 ++++ 25 files changed, 584 insertions(+), 131 deletions(-) create mode 100644 libgomp/testsuite/libgomp.c-c++-common/task-detach-10.c create mode 100644 libgomp/testsuite/libgomp.c-c++-common/task-detach-11.c create mode 100644 libgomp/testsuite/libgomp.c-c++-common/task-detach-7.c create mode 100644 libgomp/testsuite/libgomp.c-c++-common/task-detach-8.c create mode 100644 libgomp/testsuite/libgomp.c-c++-common/task-detach-9.c create mode 100644 libgomp/testsuite/libgomp.fortran/task-detach-10.f90 create mode 100644 libgomp/testsuite/libgomp.fortran/task-detach-11.f90 create mode 100644 libgomp/testsuite/libgomp.fortran/task-detach-7.f90 create mode 100644 libgomp/testsuite/libgomp.fortran/task-detach-8.f90 create mode 100644 libgomp/testsuite/libgomp.fortran/task-detach-9.f90 diff --git a/libgomp/libgomp.h b/libgomp/libgomp.h index b4d0c93..cd10d12 100644 --- a/libgomp/libgomp.h +++ b/libgomp/libgomp.h @@ -481,7 +481,10 @@ enum gomp_task_kind but not yet completed. Once that completes, they will be readded into the queues as GOMP_TASK_WAITING in order to perform the var unmapping. */ - GOMP_TASK_ASYNC_RUNNING + GOMP_TASK_ASYNC_RUNNING, + /* Task that has finished executing but is waiting for its + completion event to be fulfilled. */ + GOMP_TASK_DETACHED }; struct gomp_task_depend_entry @@ -545,8 +548,15 @@ struct gomp_task entries and the gomp_task in which they reside. */ struct priority_node pnode[3]; - bool detach; - gomp_sem_t completion_sem; + union { + /* Valid only if deferred_p is false. */ + gomp_sem_t *completion_sem; + /* Valid only if deferred_p is true. Set to the team that executes the + task if the task is detached and the completion event has yet to be + fulfilled. */ + struct gomp_team *detach_team; + }; + bool deferred_p; struct gomp_task_icv icv; void (*fn) (void *); @@ -688,8 +698,7 @@ struct gomp_team int work_share_cancelled; int team_cancelled; - /* Tasks waiting for their completion event to be fulfilled. */ - struct priority_queue task_detach_queue; + /* Number of tasks waiting for their completion event to be fulfilled. */ unsigned int task_detach_count; /* This array contains structures for implicit tasks. */ diff --git a/libgomp/task.c b/libgomp/task.c index b242e7c..79df733 100644 --- a/libgomp/task.c +++ b/libgomp/task.c @@ -29,6 +29,7 @@ #include "libgomp.h" #include <stdlib.h> #include <string.h> +#include <assert.h> #include "gomp-constants.h" typedef struct gomp_task_depend_entry *hash_entry_type; @@ -86,7 +87,8 @@ gomp_init_task (struct gomp_task *task, struct gomp_task *parent_task, task->dependers = NULL; task->depend_hash = NULL; task->depend_count = 0; - task->detach = false; + task->deferred_p = true; + task->detach_team = NULL; } /* Clean up a task, after completing it. */ @@ -327,12 +329,6 @@ gomp_task_handle_depend (struct gomp_task *task, struct gomp_task *parent, } } -static bool -task_fulfilled_p (struct gomp_task *task) -{ - return gomp_sem_getcount (&task->completion_sem) > 0; -} - /* Called when encountering an explicit task directive. If IF_CLAUSE is false, then we must not delay in executing the task. If UNTIED is true, then the task may be executed by any member of the team. @@ -398,6 +394,7 @@ GOMP_task (void (*fn) (void *), void *data, void (*cpyfn) (void *, void *), || team->task_count > 64 * team->nthreads) { struct gomp_task task; + gomp_sem_t completion_sem; /* If there are depend clauses and earlier deferred sibling tasks with depend clauses, check if there isn't a dependency. If there @@ -414,16 +411,18 @@ GOMP_task (void (*fn) (void *), void *data, void (*cpyfn) (void *, void *), task.final_task = (thr->task && thr->task->final_task) || (flags & GOMP_TASK_FLAG_FINAL); task.priority = priority; + task.deferred_p = false; if ((flags & GOMP_TASK_FLAG_DETACH) != 0) { - task.detach = true; - gomp_sem_init (&task.completion_sem, 0); - *(void **) detach = &task.completion_sem; + gomp_sem_init (&completion_sem, 0); + task.completion_sem = &completion_sem; + *(void **) detach = &task; if (data) - *(void **) data = &task.completion_sem; + *(void **) data = &task; - gomp_debug (0, "New event: %p\n", &task.completion_sem); + gomp_debug (0, "Thread %d: new event: %p\n", + thr->ts.team_id, &task); } if (thr->task) @@ -443,8 +442,8 @@ GOMP_task (void (*fn) (void *), void *data, void (*cpyfn) (void *, void *), else fn (data); - if (task.detach && !task_fulfilled_p (&task)) - gomp_sem_wait (&task.completion_sem); + if ((flags & GOMP_TASK_FLAG_DETACH) != 0 && detach) + gomp_sem_wait (&completion_sem); /* Access to "children" is normally done inside a task_lock mutex region, but the only way this particular task.children @@ -484,15 +483,16 @@ GOMP_task (void (*fn) (void *), void *data, void (*cpyfn) (void *, void *), task->kind = GOMP_TASK_UNDEFERRED; task->in_tied_task = parent->in_tied_task; task->taskgroup = taskgroup; + task->deferred_p = true; if ((flags & GOMP_TASK_FLAG_DETACH) != 0) { - task->detach = true; - gomp_sem_init (&task->completion_sem, 0); - *(void **) detach = &task->completion_sem; + task->detach_team = team; + + *(void **) detach = task; if (data) - *(void **) data = &task->completion_sem; + *(void **) data = task; - gomp_debug (0, "New event: %p\n", &task->completion_sem); + gomp_debug (0, "Thread %d: new event: %p\n", thr->ts.team_id, task); } thr->task = task; if (cpyfn) @@ -1362,27 +1362,6 @@ gomp_barrier_handle_tasks (gomp_barrier_state_t state) { bool cancelled = false; - /* Look for a queued detached task with a fulfilled completion event - that is ready to finish. */ - child_task = priority_queue_find (PQ_TEAM, &team->task_detach_queue, - task_fulfilled_p); - if (child_task) - { - priority_queue_remove (PQ_TEAM, &team->task_detach_queue, - child_task, MEMMODEL_RELAXED); - --team->task_detach_count; - gomp_debug (0, "thread %d: found task with fulfilled event %p\n", - thr->ts.team_id, &child_task->completion_sem); - - if (to_free) - { - gomp_finish_task (to_free); - free (to_free); - to_free = NULL; - } - goto finish_cancelled; - } - if (!priority_queue_empty_p (&team->task_queue, MEMMODEL_RELAXED)) { bool ignored; @@ -1405,6 +1384,19 @@ gomp_barrier_handle_tasks (gomp_barrier_state_t state) team->task_running_count++; child_task->in_tied_task = true; } + else if (team->task_count == 0 + && gomp_team_barrier_waiting_for_tasks (&team->barrier)) + { + gomp_team_barrier_done (&team->barrier, state); + gomp_mutex_unlock (&team->task_lock); + gomp_team_barrier_wake (&team->barrier, 0); + if (to_free) + { + gomp_finish_task (to_free); + free (to_free); + } + return; + } gomp_mutex_unlock (&team->task_lock); if (do_wake) { @@ -1450,44 +1442,37 @@ gomp_barrier_handle_tasks (gomp_barrier_state_t state) gomp_mutex_lock (&team->task_lock); if (child_task) { - if (child_task->detach && !task_fulfilled_p (child_task)) + if (child_task->detach_team) { - priority_queue_insert (PQ_TEAM, &team->task_detach_queue, - child_task, child_task->priority, - PRIORITY_INSERT_END, - false, false); + assert (child_task->detach_team == team); + child_task->kind = GOMP_TASK_DETACHED; ++team->task_detach_count; - gomp_debug (0, "thread %d: queueing task with event %p\n", - thr->ts.team_id, &child_task->completion_sem); + --team->task_running_count; + gomp_debug (0, + "thread %d: task with event %p finished without " + "completion event fulfilled in team barrier\n", + thr->ts.team_id, child_task); child_task = NULL; + continue; } - else + + finish_cancelled:; + size_t new_tasks + = gomp_task_run_post_handle_depend (child_task, team); + gomp_task_run_post_remove_parent (child_task); + gomp_clear_parent (&child_task->children_queue); + gomp_task_run_post_remove_taskgroup (child_task); + to_free = child_task; + if (!cancelled) + team->task_running_count--; + child_task = NULL; + if (new_tasks > 1) { - finish_cancelled:; - size_t new_tasks - = gomp_task_run_post_handle_depend (child_task, team); - gomp_task_run_post_remove_parent (child_task); - gomp_clear_parent (&child_task->children_queue); - gomp_task_run_post_remove_taskgroup (child_task); - to_free = child_task; - child_task = NULL; - if (!cancelled) - team->task_running_count--; - if (new_tasks > 1) - { - do_wake = team->nthreads - team->task_running_count; - if (do_wake > new_tasks) - do_wake = new_tasks; - } - if (--team->task_count == 0 - && gomp_team_barrier_waiting_for_tasks (&team->barrier)) - { - gomp_team_barrier_done (&team->barrier, state); - gomp_mutex_unlock (&team->task_lock); - gomp_team_barrier_wake (&team->barrier, 0); - gomp_mutex_lock (&team->task_lock); - } + do_wake = team->nthreads - team->task_running_count; + if (do_wake > new_tasks) + do_wake = new_tasks; } + --team->task_count; } } } @@ -1559,7 +1544,8 @@ GOMP_taskwait (void) else { /* All tasks we are waiting for are either running in other - threads, or they are tasks that have not had their + threads, are detached and waiting for the completion event to be + fulfilled, or they are tasks that have not had their dependencies met (so they're not even in the queue). Wait for them. */ if (task->taskwait == NULL) @@ -1614,6 +1600,19 @@ GOMP_taskwait (void) gomp_mutex_lock (&team->task_lock); if (child_task) { + if (child_task->detach_team) + { + assert (child_task->detach_team == team); + child_task->kind = GOMP_TASK_DETACHED; + ++team->task_detach_count; + gomp_debug (0, + "thread %d: task with event %p finished without " + "completion event fulfilled in taskwait\n", + thr->ts.team_id, child_task); + child_task = NULL; + continue; + } + finish_cancelled:; size_t new_tasks = gomp_task_run_post_handle_depend (child_task, team); @@ -2069,6 +2068,19 @@ GOMP_taskgroup_end (void) gomp_mutex_lock (&team->task_lock); if (child_task) { + if (child_task->detach_team) + { + assert (child_task->detach_team == team); + child_task->kind = GOMP_TASK_DETACHED; + ++team->task_detach_count; + gomp_debug (0, + "thread %d: task with event %p finished without " + "completion event fulfilled in taskgroup\n", + thr->ts.team_id, child_task); + child_task = NULL; + continue; + } + finish_cancelled:; size_t new_tasks = gomp_task_run_post_handle_depend (child_task, team); @@ -2402,17 +2414,77 @@ ialias (omp_in_final) void omp_fulfill_event (omp_event_handle_t event) { - gomp_sem_t *sem = (gomp_sem_t *) event; - struct gomp_thread *thr = gomp_thread (); - struct gomp_team *team = thr ? thr->ts.team : NULL; + struct gomp_task *task = (struct gomp_task *) event; + if (!task->deferred_p) + { + if (gomp_sem_getcount (task->completion_sem) > 0) + gomp_fatal ("omp_fulfill_event: %p event already fulfilled!\n", task); - if (gomp_sem_getcount (sem) > 0) - gomp_fatal ("omp_fulfill_event: %p event already fulfilled!\n", sem); + gomp_debug (0, "omp_fulfill_event: %p event for undeferred task\n", + task); + gomp_sem_post (task->completion_sem); + return; + } - gomp_debug (0, "omp_fulfill_event: %p\n", sem); - gomp_sem_post (sem); - if (team) - gomp_team_barrier_wake (&team->barrier, 1); + struct gomp_team *team = __atomic_load_n (&task->detach_team, + MEMMODEL_RELAXED); + if (!team) + gomp_fatal ("omp_fulfill_event: %p event is invalid or has already " + "been fulfilled!\n", task); + + gomp_mutex_lock (&team->task_lock); + if (task->kind != GOMP_TASK_DETACHED) + { + /* The task has not finished running yet. */ + gomp_debug (0, + "omp_fulfill_event: %p event fulfilled for unfinished " + "task\n", task); + __atomic_store_n (&task->detach_team, NULL, MEMMODEL_RELAXED); + gomp_mutex_unlock (&team->task_lock); + return; + } + + gomp_debug (0, "omp_fulfill_event: %p event fulfilled for finished task\n", + task); + size_t new_tasks = gomp_task_run_post_handle_depend (task, team); + gomp_task_run_post_remove_parent (task); + gomp_clear_parent (&task->children_queue); + gomp_task_run_post_remove_taskgroup (task); + team->task_count--; + team->task_detach_count--; + + int do_wake = 0; + bool shackled_thread_p = team == gomp_thread ()->ts.team; + if (new_tasks > 0) + { + /* Wake up threads to run new tasks. */ + do_wake = team->nthreads - team->task_running_count; + if (do_wake > new_tasks) + do_wake = new_tasks; + } + + if (!shackled_thread_p + && !do_wake + && gomp_team_barrier_waiting_for_tasks (&team->barrier) + && team->task_detach_count == 0) + { + /* Ensure that at least one thread is woken up to signal that the + barrier can finish. */ + do_wake = 1; + } + + /* If we are running in an unshackled thread, the team might vanish before + gomp_team_barrier_wake is run if we release the lock first, so keep the + lock for the call in that case. */ + if (shackled_thread_p) + gomp_mutex_unlock (&team->task_lock); + if (do_wake) + gomp_team_barrier_wake (&team->barrier, do_wake); + if (!shackled_thread_p) + gomp_mutex_unlock (&team->task_lock); + + gomp_finish_task (task); + free (task); } ialias (omp_fulfill_event) diff --git a/libgomp/team.c b/libgomp/team.c index 0f3707c..9662234 100644 --- a/libgomp/team.c +++ b/libgomp/team.c @@ -206,7 +206,6 @@ gomp_new_team (unsigned nthreads) team->work_share_cancelled = 0; team->team_cancelled = 0; - priority_queue_init (&team->task_detach_queue); team->task_detach_count = 0; return team; @@ -224,7 +223,6 @@ free_team (struct gomp_team *team) gomp_barrier_destroy (&team->barrier); gomp_mutex_destroy (&team->task_lock); priority_queue_free (&team->task_queue); - priority_queue_free (&team->task_detach_queue); team_free (team); } diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-1.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-1.c index 8583e37..14932b0 100644 --- a/libgomp/testsuite/libgomp.c-c++-common/task-detach-1.c +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-1.c @@ -14,10 +14,10 @@ int main (void) #pragma omp parallel #pragma omp single { - #pragma omp task detach(detach_event1) + #pragma omp task detach (detach_event1) x++; - #pragma omp task detach(detach_event2) + #pragma omp task detach (detach_event2) { y++; omp_fulfill_event (detach_event1); diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-10.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-10.c new file mode 100644 index 0000000..10d6746 --- /dev/null +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-10.c @@ -0,0 +1,45 @@ +/* { dg-do run } */ + +#include <omp.h> +#include <assert.h> + +/* Test tasks with detach clause on an offload device. Each device + thread spawns off a chain of tasks in a taskgroup, that can then + be executed by any available thread. */ + +int main (void) +{ + int x = 0, y = 0, z = 0; + int thread_count; + omp_event_handle_t detach_event1, detach_event2; + + #pragma omp target map (tofrom: x, y, z) map (from: thread_count) + #pragma omp parallel private (detach_event1, detach_event2) + #pragma omp taskgroup + { + #pragma omp single + thread_count = omp_get_num_threads (); + + #pragma omp task detach (detach_event1) untied + #pragma omp atomic update + x++; + + #pragma omp task detach (detach_event2) untied + { + #pragma omp atomic update + y++; + omp_fulfill_event (detach_event1); + } + + #pragma omp task untied + { + #pragma omp atomic update + z++; + omp_fulfill_event (detach_event2); + } + } + + assert (x == thread_count); + assert (y == thread_count); + assert (z == thread_count); +} diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-11.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-11.c new file mode 100644 index 0000000..dd002dc --- /dev/null +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-11.c @@ -0,0 +1,13 @@ +/* { dg-do run } */ + +#include <omp.h> + +/* Test the detach clause when the task is undeferred. */ + +int main (void) +{ + omp_event_handle_t event; + + #pragma omp task detach (event) + omp_fulfill_event (event); +} diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-2.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-2.c index 943ac2a..3e33c40 100644 --- a/libgomp/testsuite/libgomp.c-c++-common/task-detach-2.c +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-2.c @@ -12,13 +12,13 @@ int main (void) omp_event_handle_t detach_event1, detach_event2; int x = 0, y = 0, z = 0; - #pragma omp parallel num_threads(1) + #pragma omp parallel num_threads (1) #pragma omp single { - #pragma omp task detach(detach_event1) + #pragma omp task detach (detach_event1) x++; - #pragma omp task detach(detach_event2) + #pragma omp task detach (detach_event2) { y++; omp_fulfill_event (detach_event1); diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-3.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-3.c index 2609fb1..c85857d 100644 --- a/libgomp/testsuite/libgomp.c-c++-common/task-detach-3.c +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-3.c @@ -14,16 +14,16 @@ int main (void) #pragma omp parallel #pragma omp single { - #pragma omp task depend(out:dep) detach(detach_event) + #pragma omp task depend (out:dep) detach (detach_event) x++; #pragma omp task { y++; - omp_fulfill_event(detach_event); + omp_fulfill_event (detach_event); } - #pragma omp task depend(in:dep) + #pragma omp task depend (in:dep) z++; } diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-4.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-4.c index eeb9554..cd0d2b3 100644 --- a/libgomp/testsuite/libgomp.c-c++-common/task-detach-4.c +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-4.c @@ -14,10 +14,10 @@ int main (void) #pragma omp parallel #pragma omp single - #pragma omp task detach(detach_event) + #pragma omp task detach (detach_event) { x++; - omp_fulfill_event(detach_event); + omp_fulfill_event (detach_event); } assert (x == 1); diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-5.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-5.c index 5a01517..382f377 100644 --- a/libgomp/testsuite/libgomp.c-c++-common/task-detach-5.c +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-5.c @@ -12,16 +12,16 @@ int main (void) int thread_count; omp_event_handle_t detach_event1, detach_event2; - #pragma omp parallel firstprivate(detach_event1, detach_event2) + #pragma omp parallel private (detach_event1, detach_event2) { #pragma omp single - thread_count = omp_get_num_threads(); + thread_count = omp_get_num_threads (); - #pragma omp task detach(detach_event1) untied + #pragma omp task detach (detach_event1) untied #pragma omp atomic update x++; - #pragma omp task detach(detach_event2) untied + #pragma omp task detach (detach_event2) untied { #pragma omp atomic update y++; diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-6.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-6.c index b5f68cc..e5c2291 100644 --- a/libgomp/testsuite/libgomp.c-c++-common/task-detach-6.c +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-6.c @@ -13,11 +13,11 @@ int main (void) int thread_count; omp_event_handle_t detach_event1, detach_event2; - #pragma omp target map(tofrom: x, y, z) map(from: thread_count) - #pragma omp parallel firstprivate(detach_event1, detach_event2) + #pragma omp target map (tofrom: x, y, z) map (from: thread_count) + #pragma omp parallel private (detach_event1, detach_event2) { #pragma omp single - thread_count = omp_get_num_threads(); + thread_count = omp_get_num_threads (); #pragma omp task detach(detach_event1) untied #pragma omp atomic update @@ -36,8 +36,6 @@ int main (void) z++; omp_fulfill_event (detach_event2); } - - #pragma omp taskwait } assert (x == thread_count); diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-7.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-7.c new file mode 100644 index 0000000..3f025d6 --- /dev/null +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-7.c @@ -0,0 +1,45 @@ +/* { dg-do run } */ + +#include <omp.h> +#include <assert.h> + +/* Test tasks with detach clause. Each thread spawns off a chain of tasks, + that can then be executed by any available thread. Each thread uses + taskwait to wait for the child tasks to complete. */ + +int main (void) +{ + int x = 0, y = 0, z = 0; + int thread_count; + omp_event_handle_t detach_event1, detach_event2; + + #pragma omp parallel private (detach_event1, detach_event2) + { + #pragma omp single + thread_count = omp_get_num_threads (); + + #pragma omp task detach (detach_event1) untied + #pragma omp atomic update + x++; + + #pragma omp task detach (detach_event2) untied + { + #pragma omp atomic update + y++; + omp_fulfill_event (detach_event1); + } + + #pragma omp task untied + { + #pragma omp atomic update + z++; + omp_fulfill_event (detach_event2); + } + + #pragma omp taskwait + } + + assert (x == thread_count); + assert (y == thread_count); + assert (z == thread_count); +} diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-8.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-8.c new file mode 100644 index 0000000..6f77f12 --- /dev/null +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-8.c @@ -0,0 +1,47 @@ +/* { dg-do run } */ + +#include <omp.h> +#include <assert.h> + +/* Test tasks with detach clause on an offload device. Each device + thread spawns off a chain of tasks, that can then be executed by + any available thread. Each thread uses taskwait to wait for the + child tasks to complete. */ + +int main (void) +{ + int x = 0, y = 0, z = 0; + int thread_count; + omp_event_handle_t detach_event1, detach_event2; + + #pragma omp target map (tofrom: x, y, z) map (from: thread_count) + #pragma omp parallel private (detach_event1, detach_event2) + { + #pragma omp single + thread_count = omp_get_num_threads (); + + #pragma omp task detach (detach_event1) untied + #pragma omp atomic update + x++; + + #pragma omp task detach (detach_event2) untied + { + #pragma omp atomic update + y++; + omp_fulfill_event (detach_event1); + } + + #pragma omp task untied + { + #pragma omp atomic update + z++; + omp_fulfill_event (detach_event2); + } + + #pragma omp taskwait + } + + assert (x == thread_count); + assert (y == thread_count); + assert (z == thread_count); +} diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-9.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-9.c new file mode 100644 index 0000000..5316ca5 --- /dev/null +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-9.c @@ -0,0 +1,43 @@ +/* { dg-do run } */ + +#include <omp.h> +#include <assert.h> + +/* Test tasks with detach clause. Each thread spawns off a chain of tasks + in a taskgroup, that can then be executed by any available thread. */ + +int main (void) +{ + int x = 0, y = 0, z = 0; + int thread_count; + omp_event_handle_t detach_event1, detach_event2; + + #pragma omp parallel private (detach_event1, detach_event2) + #pragma omp taskgroup + { + #pragma omp single + thread_count = omp_get_num_threads (); + + #pragma omp task detach (detach_event1) untied + #pragma omp atomic update + x++; + + #pragma omp task detach (detach_event2) untied + { + #pragma omp atomic update + y++; + omp_fulfill_event (detach_event1); + } + + #pragma omp task untied + { + #pragma omp atomic update + z++; + omp_fulfill_event (detach_event2); + } + } + + assert (x == thread_count); + assert (y == thread_count); + assert (z == thread_count); +} diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-1.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-1.f90 index 217bf65..c53b1ca 100644 --- a/libgomp/testsuite/libgomp.fortran/task-detach-1.f90 +++ b/libgomp/testsuite/libgomp.fortran/task-detach-1.f90 @@ -11,11 +11,11 @@ program task_detach_1 !$omp parallel !$omp single - !$omp task detach(detach_event1) + !$omp task detach (detach_event1) x = x + 1 !$omp end task - !$omp task detach(detach_event2) + !$omp task detach (detach_event2) y = y + 1 call omp_fulfill_event (detach_event1) !$omp end task diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-10.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-10.f90 new file mode 100644 index 0000000..61f0ea8 --- /dev/null +++ b/libgomp/testsuite/libgomp.fortran/task-detach-10.f90 @@ -0,0 +1,44 @@ +! { dg-do run } + +! Test tasks with detach clause on an offload device. Each device +! thread spawns off a chain of tasks in a taskgroup, that can then +! be executed by any available thread. + +program task_detach_10 + use omp_lib + + integer (kind=omp_event_handle_kind) :: detach_event1, detach_event2 + integer :: x = 0, y = 0, z = 0 + integer :: thread_count + + !$omp target map (tofrom: x, y, z) map (from: thread_count) + !$omp parallel private (detach_event1, detach_event2) + !$omp taskgroup + !$omp single + thread_count = omp_get_num_threads () + !$omp end single + + !$omp task detach (detach_event1) untied + !$omp atomic update + x = x + 1 + !$omp end task + + !$omp task detach (detach_event2) untied + !$omp atomic update + y = y + 1 + call omp_fulfill_event (detach_event1) + !$omp end task + + !$omp task untied + !$omp atomic update + z = z + 1 + call omp_fulfill_event (detach_event2) + !$omp end task + !$omp end taskgroup + !$omp end parallel + !$omp end target + + if (x /= thread_count) stop 1 + if (y /= thread_count) stop 2 + if (z /= thread_count) stop 3 +end program diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-11.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-11.f90 new file mode 100644 index 0000000..b33baff --- /dev/null +++ b/libgomp/testsuite/libgomp.fortran/task-detach-11.f90 @@ -0,0 +1,13 @@ +! { dg-do run } + +! Test the detach clause when the task is undeferred. + +program task_detach_11 + use omp_lib + + integer (kind=omp_event_handle_kind) :: detach_event + + !$omp task detach (detach_event) + call omp_fulfill_event (detach_event) + !$omp end task +end program diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-2.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-2.f90 index ecb4829..68e3ff2 100644 --- a/libgomp/testsuite/libgomp.fortran/task-detach-2.f90 +++ b/libgomp/testsuite/libgomp.fortran/task-detach-2.f90 @@ -10,13 +10,13 @@ program task_detach_2 integer (kind=omp_event_handle_kind) :: detach_event1, detach_event2 integer :: x = 0, y = 0, z = 0 - !$omp parallel num_threads(1) + !$omp parallel num_threads (1) !$omp single - !$omp task detach(detach_event1) + !$omp task detach (detach_event1) x = x + 1 !$omp end task - !$omp task detach(detach_event2) + !$omp task detach (detach_event2) y = y + 1 call omp_fulfill_event (detach_event1) !$omp end task diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-3.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-3.f90 index bdf93a5..5ac68d5 100644 --- a/libgomp/testsuite/libgomp.fortran/task-detach-3.f90 +++ b/libgomp/testsuite/libgomp.fortran/task-detach-3.f90 @@ -12,16 +12,16 @@ program task_detach_3 !$omp parallel !$omp single - !$omp task depend(out:dep) detach(detach_event) + !$omp task depend (out:dep) detach (detach_event) x = x + 1 !$omp end task !$omp task y = y + 1 - call omp_fulfill_event(detach_event) + call omp_fulfill_event (detach_event) !$omp end task - !$omp task depend(in:dep) + !$omp task depend (in:dep) z = z + 1 !$omp end task !$omp end single diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-4.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-4.f90 index 6d0843c..159624c 100644 --- a/libgomp/testsuite/libgomp.fortran/task-detach-4.f90 +++ b/libgomp/testsuite/libgomp.fortran/task-detach-4.f90 @@ -11,9 +11,9 @@ program task_detach_4 !$omp parallel !$omp single - !$omp task detach(detach_event) + !$omp task detach (detach_event) x = x + 1 - call omp_fulfill_event(detach_event) + call omp_fulfill_event (detach_event) !$omp end task !$omp end single !$omp end parallel diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-5.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-5.f90 index 955d687..95bd132 100644 --- a/libgomp/testsuite/libgomp.fortran/task-detach-5.f90 +++ b/libgomp/testsuite/libgomp.fortran/task-detach-5.f90 @@ -10,17 +10,17 @@ program task_detach_5 integer :: x = 0, y = 0, z = 0 integer :: thread_count - !$omp parallel firstprivate(detach_event1, detach_event2) + !$omp parallel private (detach_event1, detach_event2) !$omp single - thread_count = omp_get_num_threads() + thread_count = omp_get_num_threads () !$omp end single - !$omp task detach(detach_event1) untied + !$omp task detach (detach_event1) untied !$omp atomic update x = x + 1 !$omp end task - !$omp task detach(detach_event2) untied + !$omp task detach (detach_event2) untied !$omp atomic update y = y + 1 call omp_fulfill_event (detach_event1); diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-6.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-6.f90 index 0fe2155..b2c476f 100644 --- a/libgomp/testsuite/libgomp.fortran/task-detach-6.f90 +++ b/libgomp/testsuite/libgomp.fortran/task-detach-6.f90 @@ -11,30 +11,28 @@ program task_detach_6 integer :: x = 0, y = 0, z = 0 integer :: thread_count - !$omp target map(tofrom: x, y, z) map(from: thread_count) - !$omp parallel firstprivate(detach_event1, detach_event2) + !$omp target map (tofrom: x, y, z) map (from: thread_count) + !$omp parallel private (detach_event1, detach_event2) !$omp single - thread_count = omp_get_num_threads() + thread_count = omp_get_num_threads () !$omp end single - !$omp task detach(detach_event1) untied + !$omp task detach (detach_event1) untied !$omp atomic update x = x + 1 !$omp end task - !$omp task detach(detach_event2) untied + !$omp task detach (detach_event2) untied !$omp atomic update y = y + 1 - call omp_fulfill_event (detach_event1); + call omp_fulfill_event (detach_event1) !$omp end task !$omp task untied !$omp atomic update z = z + 1 - call omp_fulfill_event (detach_event2); + call omp_fulfill_event (detach_event2) !$omp end task - - !$omp taskwait !$omp end parallel !$omp end target diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-7.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-7.f90 new file mode 100644 index 0000000..32e715e --- /dev/null +++ b/libgomp/testsuite/libgomp.fortran/task-detach-7.f90 @@ -0,0 +1,42 @@ +! { dg-do run } + +! Test tasks with detach clause. Each thread spawns off a chain of tasks, +! that can then be executed by any available thread. Each thread uses +! taskwait to wait for the child tasks to complete. + +program task_detach_7 + use omp_lib + + integer (kind=omp_event_handle_kind) :: detach_event1, detach_event2 + integer :: x = 0, y = 0, z = 0 + integer :: thread_count + + !$omp parallel private (detach_event1, detach_event2) + !$omp single + thread_count = omp_get_num_threads() + !$omp end single + + !$omp task detach (detach_event1) untied + !$omp atomic update + x = x + 1 + !$omp end task + + !$omp task detach (detach_event2) untied + !$omp atomic update + y = y + 1 + call omp_fulfill_event (detach_event1) + !$omp end task + + !$omp task untied + !$omp atomic update + z = z + 1 + call omp_fulfill_event (detach_event2) + !$omp end task + + !$omp taskwait + !$omp end parallel + + if (x /= thread_count) stop 1 + if (y /= thread_count) stop 2 + if (z /= thread_count) stop 3 +end program diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-8.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-8.f90 new file mode 100644 index 0000000..e760eab --- /dev/null +++ b/libgomp/testsuite/libgomp.fortran/task-detach-8.f90 @@ -0,0 +1,45 @@ +! { dg-do run } + +! Test tasks with detach clause on an offload device. Each device +! thread spawns off a chain of tasks, that can then be executed by +! any available thread. Each thread uses taskwait to wait for the +! child tasks to complete. + +program task_detach_8 + use omp_lib + + integer (kind=omp_event_handle_kind) :: detach_event1, detach_event2 + integer :: x = 0, y = 0, z = 0 + integer :: thread_count + + !$omp target map (tofrom: x, y, z) map (from: thread_count) + !$omp parallel private (detach_event1, detach_event2) + !$omp single + thread_count = omp_get_num_threads () + !$omp end single + + !$omp task detach (detach_event1) untied + !$omp atomic update + x = x + 1 + !$omp end task + + !$omp task detach (detach_event2) untied + !$omp atomic update + y = y + 1 + call omp_fulfill_event (detach_event1) + !$omp end task + + !$omp task untied + !$omp atomic update + z = z + 1 + call omp_fulfill_event (detach_event2) + !$omp end task + + !$omp taskwait + !$omp end parallel + !$omp end target + + if (x /= thread_count) stop 1 + if (y /= thread_count) stop 2 + if (z /= thread_count) stop 3 +end program diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-9.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-9.f90 new file mode 100644 index 0000000..540c6de --- /dev/null +++ b/libgomp/testsuite/libgomp.fortran/task-detach-9.f90 @@ -0,0 +1,41 @@ +! { dg-do run } + +! Test tasks with detach clause. Each thread spawns off a chain of tasks +! in a taskgroup, that can then be executed by any available thread. + +program task_detach_9 + use omp_lib + + integer (kind=omp_event_handle_kind) :: detach_event1, detach_event2 + integer :: x = 0, y = 0, z = 0 + integer :: thread_count + + !$omp parallel private (detach_event1, detach_event2) + !$omp taskgroup + !$omp single + thread_count = omp_get_num_threads () + !$omp end single + + !$omp task detach (detach_event1) untied + !$omp atomic update + x = x + 1 + !$omp end task + + !$omp task detach (detach_event2) untied + !$omp atomic update + y = y + 1 + call omp_fulfill_event (detach_event1); + !$omp end task + + !$omp task untied + !$omp atomic update + z = z + 1 + call omp_fulfill_event (detach_event2); + !$omp end task + !$omp end taskgroup + !$omp end parallel + + if (x /= thread_count) stop 1 + if (y /= thread_count) stop 2 + if (z /= thread_count) stop 3 +end program
On Wed, Feb 24, 2021 at 06:17:01PM +0000, Kwok Cheung Yeung wrote: > > 1) while linux --enable-futex and accel gomp_sem_t is small (int), rtems > > and especially posix gomp_sem_t is large; so while it might be a good > > idea to inline gomp_sem_t on config/{linux,accel} into the union, for > > the rest it might be better to use indirection; if it is only for the > > undeferred tasks, it could be just using an automatic variable and > > put into the struct address of that; could be done either always, > > or define some macro in config/{linux,accel}/sem.h that gomp_sem_t is > > small and decide on the indirection based on that macro > > I think a pointer to an automatic variable would be simplest. Agreed. > Can anything in cpyfn make use of the fact that kind==GOMP_TASK_UNDEFERRED > while executing it? Anyway, if we want to keep this, then I suppose we could > just add an extra field deferred_p that does not change for the lifetime of > the task to indicate that the task is 'really' a deferred task. Adding a bool is fine, but see bellow. > > 3) kind is not constant, for the deferred tasks it can change over the > > lifetime of the task, as you've said in the comments, it is kind == > > GOMP_TASK_UNDEFERRED vs. other values; while the changes of task->kind > > are done while holding the task lock, omp_fulfill_event reads it before > > locking that lock, so I think it needs to be done using > > if (__atomic_load_n (&task->kind, MEMMODEL_RELAXED) == GOMP_TASK_UNDEFERRED) > > Pedantically the stores to task->kind also need to be done > > with __atomic_store_n MEMMODEL_RELAXED. > > If we check task->deferred_p instead (which never changes for a task after > instantiation), is that still necessary? Not for kind or the new field. > > - in gomp_barrier_handle_tasks the reason for if (new_tasks > 1) > > is that if there is a single dependent task, the current thread > > just finished handling one task and so can take that single task and so no > > need to wake up. While in the omp_fulfill_event case, even if there > > is just one new task, we need to schedule it to some thread and so > > is desirable to wake some thread. > > In that case, we could just do 'if (new_tasks > 0)' instead? Yes. > > > All we know > > (if team == gomp_thread ()->ts.team) is that at least one thread is doing > > something else but that one could be busy for quite some time. > > Well, it should still get around to the new task eventually, so there is no > problem in terms of correctness here. I suppose we could always wake up one > more thread than strictly necessary, but that might have knock-on effects on > performance elsewhere? Yeah, waking something unnecessarily is always going to cause performance problems. > I have applied your patch to move the gomp_team_barrier_done, and in > omp_fulfill_event, I ensure that a single thread is woken up so that > gomp_barrier_handle_tasks can signal for the barrier to finish. > > I'm having some trouble coming up with a testcase to test this scenario > though. I tried having a testcase like this to have threads in separate > teams: The unshackeled thread testcase would probably need a pthread_create call and restricting the testcase to POSIX threads targets. The teams in host teams (or target) don't have at least in OpenMP a way to serialize, e.g. it can always be implemented like we do ATM. But I guess that testcase can be done incrementally. > @@ -545,8 +548,15 @@ struct gomp_task > entries and the gomp_task in which they reside. */ > struct priority_node pnode[3]; > > - bool detach; > - gomp_sem_t completion_sem; > + union { > + /* Valid only if deferred_p is false. */ > + gomp_sem_t *completion_sem; > + /* Valid only if deferred_p is true. Set to the team that executes the > + task if the task is detached and the completion event has yet to be > + fulfilled. */ > + struct gomp_team *detach_team; > + }; > + bool deferred_p; > > struct gomp_task_icv icv; > void (*fn) (void *); What I don't like is that this creates too much wasteful padding in a struct that should be as small as possible. At least on 64-bit hosts which we care about most, pahole shows with your patch: struct gomp_task { struct gomp_task * parent; /* 0 8 */ struct priority_queue children_queue; /* 8 32 */ struct gomp_taskgroup * taskgroup; /* 40 8 */ struct gomp_dependers_vec * dependers; /* 48 8 */ struct htab * depend_hash; /* 56 8 */ /* --- cacheline 1 boundary (64 bytes) --- */ struct gomp_taskwait * taskwait; /* 64 8 */ size_t depend_count; /* 72 8 */ size_t num_dependees; /* 80 8 */ int priority; /* 88 4 */ /* XXX 4 bytes hole, try to pack */ struct priority_node pnode[3]; /* 96 48 */ /* --- cacheline 2 boundary (128 bytes) was 16 bytes ago --- */ union { gomp_sem_t * completion_sem; /* 144 8 */ struct gomp_team * detach_team; /* 144 8 */ }; /* 144 8 */ _Bool deferred_p; /* 152 1 */ /* XXX 7 bytes hole, try to pack */ struct gomp_task_icv icv; /* 160 40 */ /* --- cacheline 3 boundary (192 bytes) was 8 bytes ago --- */ void (*fn)(void *); /* 200 8 */ void * fn_data; /* 208 8 */ enum gomp_task_kind kind; /* 216 4 */ _Bool in_tied_task; /* 220 1 */ _Bool final_task; /* 221 1 */ _Bool copy_ctors_done; /* 222 1 */ _Bool parent_depends_on; /* 223 1 */ struct gomp_task_depend_entry depend[]; /* 224 0 */ /* size: 224, cachelines: 4, members: 21 */ /* sum members: 213, holes: 2, sum holes: 11 */ /* last cacheline: 32 bytes */ }; So perhaps it might be better to put the new 1 fields before int priority; field, in order bool deferred_p; union { }; That way, there will be just 3 bytes hole in the whole struct, not 4 + 7 byte holes. > > - if (task.detach && !task_fulfilled_p (&task)) > - gomp_sem_wait (&task.completion_sem); > + if ((flags & GOMP_TASK_FLAG_DETACH) != 0 && detach) > + gomp_sem_wait (&completion_sem); I think gomp_sem_destroy is missing here (in the conditional if it was only initialized. Furthermore, I don't understand the && detach, the earlier code assumes that if (flags & GOMP_TASK_FLAG_DETACH) != 0 then it can dereference *(void *)) detach, so the && detach seems to be unnecessary. > @@ -484,15 +483,16 @@ GOMP_task (void (*fn) (void *), void *data, void (*cpyfn) (void *, void *), > task->kind = GOMP_TASK_UNDEFERRED; > task->in_tied_task = parent->in_tied_task; > task->taskgroup = taskgroup; > + task->deferred_p = true; > if ((flags & GOMP_TASK_FLAG_DETACH) != 0) > { > - task->detach = true; > - gomp_sem_init (&task->completion_sem, 0); > - *(void **) detach = &task->completion_sem; I think you can move task->deferred_p into the if stmt. > + if (!shackled_thread_p > + && !do_wake > + && gomp_team_barrier_waiting_for_tasks (&team->barrier) > + && team->task_detach_count == 0) && team->task_detach_count == 0 is cheaper than the && gomp_team_barrier_waiting_for_tasks (&team->barrier) so please swap those two. > + { > + /* Ensure that at least one thread is woken up to signal that the > + barrier can finish. */ > + do_wake = 1; > + } Please drop the {}s around the single do_wake = 1; stmt. Otherwise LGTM. Jakub
On 24/02/2021 7:46 pm, Jakub Jelinek wrote: >> @@ -545,8 +548,15 @@ struct gomp_task >> entries and the gomp_task in which they reside. */ >> struct priority_node pnode[3]; >> >> - bool detach; >> - gomp_sem_t completion_sem; >> + union { >> + /* Valid only if deferred_p is false. */ >> + gomp_sem_t *completion_sem; >> + /* Valid only if deferred_p is true. Set to the team that executes the >> + task if the task is detached and the completion event has yet to be >> + fulfilled. */ >> + struct gomp_team *detach_team; >> + }; >> + bool deferred_p; >> >> struct gomp_task_icv icv; >> void (*fn) (void *); > > What I don't like is that this creates too much wasteful padding > in a struct that should be as small as possible. > At least on 64-bit hosts which we care about most, pahole shows with your > patch: > struct gomp_task { > struct gomp_task * parent; /* 0 8 */ > struct priority_queue children_queue; /* 8 32 */ > struct gomp_taskgroup * taskgroup; /* 40 8 */ > struct gomp_dependers_vec * dependers; /* 48 8 */ > struct htab * depend_hash; /* 56 8 */ > /* --- cacheline 1 boundary (64 bytes) --- */ > struct gomp_taskwait * taskwait; /* 64 8 */ > size_t depend_count; /* 72 8 */ > size_t num_dependees; /* 80 8 */ > int priority; /* 88 4 */ > > /* XXX 4 bytes hole, try to pack */ > > struct priority_node pnode[3]; /* 96 48 */ > /* --- cacheline 2 boundary (128 bytes) was 16 bytes ago --- */ > union { > gomp_sem_t * completion_sem; /* 144 8 */ > struct gomp_team * detach_team; /* 144 8 */ > }; /* 144 8 */ > _Bool deferred_p; /* 152 1 */ > > /* XXX 7 bytes hole, try to pack */ > > struct gomp_task_icv icv; /* 160 40 */ > /* --- cacheline 3 boundary (192 bytes) was 8 bytes ago --- */ > void (*fn)(void *); /* 200 8 */ > void * fn_data; /* 208 8 */ > enum gomp_task_kind kind; /* 216 4 */ > _Bool in_tied_task; /* 220 1 */ > _Bool final_task; /* 221 1 */ > _Bool copy_ctors_done; /* 222 1 */ > _Bool parent_depends_on; /* 223 1 */ > struct gomp_task_depend_entry depend[]; /* 224 0 */ > > /* size: 224, cachelines: 4, members: 21 */ > /* sum members: 213, holes: 2, sum holes: 11 */ > /* last cacheline: 32 bytes */ > }; > > So perhaps it might be better to put the new 1 fields before int priority; > field, in order bool deferred_p; union { }; > That way, there will be just 3 bytes hole in the whole struct, > not 4 + 7 byte holes. > Moving the fields in that order before priority results in the same holes due to the alignment requirement of the pointers: size_t num_dependees; /* 80 8 */ _Bool deferred_p; /* 88 1 */ /* XXX 7 bytes hole, try to pack */ union { gomp_sem_t * completion_sem; /* 96 8 */ struct gomp_team * detach_team; /* 96 8 */ }; /* 96 8 */ int priority; /* 104 4 */ /* XXX 4 bytes hole, try to pack */ struct priority_node pnode[3]; /* 112 48 */ Reversing the order reduces the hole to 3 bytes: size_t num_dependees; /* 80 8 */ union { gomp_sem_t * completion_sem; /* 88 8 */ struct gomp_team * detach_team; /* 88 8 */ }; /* 88 8 */ _Bool deferred_p; /* 96 1 */ /* XXX 3 bytes hole, try to pack */ int priority; /* 100 4 */ If we were really determined to get rid of the hole, we could stash deferred_p in the least-significant bit of the pointer union, but I think that might be more trouble than it is worth... >> >> - if (task.detach && !task_fulfilled_p (&task)) >> - gomp_sem_wait (&task.completion_sem); >> + if ((flags & GOMP_TASK_FLAG_DETACH) != 0 && detach) >> + gomp_sem_wait (&completion_sem); > > I think gomp_sem_destroy is missing here (in the conditional if it was > only initialized. Furthermore, I don't understand the && detach, > the earlier code assumes that if (flags & GOMP_TASK_FLAG_DETACH) != 0 > then it can dereference *(void *)) detach, so the && detach seems > to be unnecessary. I have added a call to gomp_sem_destroy, and removed the redundant check for detach. >> @@ -484,15 +483,16 @@ GOMP_task (void (*fn) (void *), void *data, void (*cpyfn) (void *, void *), >> task->kind = GOMP_TASK_UNDEFERRED; >> task->in_tied_task = parent->in_tied_task; >> task->taskgroup = taskgroup; >> + task->deferred_p = true; >> if ((flags & GOMP_TASK_FLAG_DETACH) != 0) >> { >> - task->detach = true; >> - gomp_sem_init (&task->completion_sem, 0); >> - *(void **) detach = &task->completion_sem; > > I think you can move task->deferred_p into the if stmt. That can be done (since the code for detach is currently the only thing using it), but I think it would be better to have deferred_p always have the right value, regardless of whether or not it is used? Otherwise that might lead to some confusion if it is later used by something else. >> + if (!shackled_thread_p >> + && !do_wake >> + && gomp_team_barrier_waiting_for_tasks (&team->barrier) >> + && team->task_detach_count == 0) > > && team->task_detach_count == 0 is cheaper than the > && gomp_team_barrier_waiting_for_tasks (&team->barrier) > so please swap those two. > Done. >> + { >> + /* Ensure that at least one thread is woken up to signal that the >> + barrier can finish. */ >> + do_wake = 1; >> + } > > Please drop the {}s around the single do_wake = 1; stmt. Okay. I put the braces in because it looked a little odd with the comment. > Otherwise LGTM. > I will get this committed later if the regression tests finish with no surprises. Thank you for your time in reviewing this patch! Kwok From 462c86549de28f28d5a71e4a7e83e2c17fd19c17 Mon Sep 17 00:00:00 2001 From: Kwok Cheung Yeung <kcy@codesourcery.com> Date: Thu, 21 Jan 2021 05:38:47 -0800 Subject: [PATCH] openmp: Fix intermittent hanging of task-detach-6 libgomp tests [PR98738] This adds support for the task detach clause to taskwait and taskgroup, and simplifies the handling of the detach clause by moving most of the extra handling required for detach tasks to omp_fulfill_event. 2021-02-25 Kwok Cheung Yeung <kcy@codesourcery.com> Jakub Jelinek <jakub@redhat.com> libgomp/ PR libgomp/98738 * libgomp.h (enum gomp_task_kind): Add GOMP_TASK_DETACHED. (struct gomp_task): Replace detach and completion_sem fields with union containing completion_sem and detach_team. Add deferred_p field. (struct gomp_team): Remove task_detach_queue. * task.c: Include assert.h. (gomp_init_task): Initialize deferred_p and detach_team fields. (task_fulfilled_p): Delete. (GOMP_task): Use address of task as the event handle. Remove initialization of detach field. Initialize deferred_p field. Use automatic local for completion_sem. Initialize detach_team field for deferred tasks. (gomp_barrier_handle_tasks): Remove handling of task_detach_queue. Set kind of suspended detach task to GOMP_TASK_DETACHED and decrement task_running_count. Move finish_cancelled block out of else branch. Relocate call to gomp_team_barrier_done. (GOMP_taskwait): Handle tasks with completion events that have not been fulfilled. (GOMP_taskgroup_end): Likewise. (omp_fulfill_event): Use address of task as event handle. Post to completion_sem for undeferred tasks. Clear detach_team if task has not finished. For finished tasks, handle post-execution tasks, call gomp_team_barrier_wake if necessary, and free task. * team.c (gomp_new_team): Remove initialization of task_detach_queue. (free_team): Remove free of task_detach_queue. * testsuite/libgomp.c-c++-common/task-detach-1.c: Fix formatting. * testsuite/libgomp.c-c++-common/task-detach-2.c: Fix formatting. * testsuite/libgomp.c-c++-common/task-detach-3.c: Fix formatting. * testsuite/libgomp.c-c++-common/task-detach-4.c: Fix formatting. * testsuite/libgomp.c-c++-common/task-detach-5.c: Fix formatting. Change data-sharing of detach events on enclosing parallel to private. * testsuite/libgomp.c-c++-common/task-detach-6.c: Likewise. Remove taskwait directive. * testsuite/libgomp.c-c++-common/task-detach-7.c: New. * testsuite/libgomp.c-c++-common/task-detach-8.c: New. * testsuite/libgomp.c-c++-common/task-detach-9.c: New. * testsuite/libgomp.c-c++-common/task-detach-10.c: New. * testsuite/libgomp.c-c++-common/task-detach-11.c: New. * testsuite/libgomp.c-c++-common/task-detach-1.f90: Fix formatting. * testsuite/libgomp.c-c++-common/task-detach-2.f90: Fix formatting. * testsuite/libgomp.c-c++-common/task-detach-3.f90: Fix formatting. * testsuite/libgomp.c-c++-common/task-detach-4.f90: Fix formatting. * testsuite/libgomp.fortran/task-detach-5.f90: Fix formatting. Change data-sharing of detach events on enclosing parallel to private. * testsuite/libgomp.fortran/task-detach-6.f90: Likewise. Remove taskwait directive. * testsuite/libgomp.c-c++-common/task-detach-7.f90: New. * testsuite/libgomp.c-c++-common/task-detach-8.f90: New. * testsuite/libgomp.c-c++-common/task-detach-9.f90: New. * testsuite/libgomp.c-c++-common/task-detach-10.f90: New. * testsuite/libgomp.c-c++-common/task-detach-11.f90: New. --- libgomp/libgomp.h | 21 +- libgomp/task.c | 237 ++++++++++++++------- libgomp/team.c | 2 - .../testsuite/libgomp.c-c++-common/task-detach-1.c | 4 +- .../libgomp.c-c++-common/task-detach-10.c | 45 ++++ .../libgomp.c-c++-common/task-detach-11.c | 13 ++ .../testsuite/libgomp.c-c++-common/task-detach-2.c | 6 +- .../testsuite/libgomp.c-c++-common/task-detach-3.c | 6 +- .../testsuite/libgomp.c-c++-common/task-detach-4.c | 4 +- .../testsuite/libgomp.c-c++-common/task-detach-5.c | 8 +- .../testsuite/libgomp.c-c++-common/task-detach-6.c | 8 +- .../testsuite/libgomp.c-c++-common/task-detach-7.c | 45 ++++ .../testsuite/libgomp.c-c++-common/task-detach-8.c | 47 ++++ .../testsuite/libgomp.c-c++-common/task-detach-9.c | 43 ++++ .../testsuite/libgomp.fortran/task-detach-1.f90 | 4 +- .../testsuite/libgomp.fortran/task-detach-10.f90 | 44 ++++ .../testsuite/libgomp.fortran/task-detach-11.f90 | 13 ++ .../testsuite/libgomp.fortran/task-detach-2.f90 | 6 +- .../testsuite/libgomp.fortran/task-detach-3.f90 | 6 +- .../testsuite/libgomp.fortran/task-detach-4.f90 | 4 +- .../testsuite/libgomp.fortran/task-detach-5.f90 | 8 +- .../testsuite/libgomp.fortran/task-detach-6.f90 | 16 +- .../testsuite/libgomp.fortran/task-detach-7.f90 | 42 ++++ .../testsuite/libgomp.fortran/task-detach-8.f90 | 45 ++++ .../testsuite/libgomp.fortran/task-detach-9.f90 | 41 ++++ 25 files changed, 586 insertions(+), 132 deletions(-) create mode 100644 libgomp/testsuite/libgomp.c-c++-common/task-detach-10.c create mode 100644 libgomp/testsuite/libgomp.c-c++-common/task-detach-11.c create mode 100644 libgomp/testsuite/libgomp.c-c++-common/task-detach-7.c create mode 100644 libgomp/testsuite/libgomp.c-c++-common/task-detach-8.c create mode 100644 libgomp/testsuite/libgomp.c-c++-common/task-detach-9.c create mode 100644 libgomp/testsuite/libgomp.fortran/task-detach-10.f90 create mode 100644 libgomp/testsuite/libgomp.fortran/task-detach-11.f90 create mode 100644 libgomp/testsuite/libgomp.fortran/task-detach-7.f90 create mode 100644 libgomp/testsuite/libgomp.fortran/task-detach-8.f90 create mode 100644 libgomp/testsuite/libgomp.fortran/task-detach-9.f90 diff --git a/libgomp/libgomp.h b/libgomp/libgomp.h index b4d0c93..ef1bb49 100644 --- a/libgomp/libgomp.h +++ b/libgomp/libgomp.h @@ -481,7 +481,10 @@ enum gomp_task_kind but not yet completed. Once that completes, they will be readded into the queues as GOMP_TASK_WAITING in order to perform the var unmapping. */ - GOMP_TASK_ASYNC_RUNNING + GOMP_TASK_ASYNC_RUNNING, + /* Task that has finished executing but is waiting for its + completion event to be fulfilled. */ + GOMP_TASK_DETACHED }; struct gomp_task_depend_entry @@ -537,6 +540,16 @@ struct gomp_task into the various queues to be scheduled. */ size_t num_dependees; + union { + /* Valid only if deferred_p is false. */ + gomp_sem_t *completion_sem; + /* Valid only if deferred_p is true. Set to the team that executes the + task if the task is detached and the completion event has yet to be + fulfilled. */ + struct gomp_team *detach_team; + }; + bool deferred_p; + /* Priority of this task. */ int priority; /* The priority node for this task in each of the different queues. @@ -545,9 +558,6 @@ struct gomp_task entries and the gomp_task in which they reside. */ struct priority_node pnode[3]; - bool detach; - gomp_sem_t completion_sem; - struct gomp_task_icv icv; void (*fn) (void *); void *fn_data; @@ -688,8 +698,7 @@ struct gomp_team int work_share_cancelled; int team_cancelled; - /* Tasks waiting for their completion event to be fulfilled. */ - struct priority_queue task_detach_queue; + /* Number of tasks waiting for their completion event to be fulfilled. */ unsigned int task_detach_count; /* This array contains structures for implicit tasks. */ diff --git a/libgomp/task.c b/libgomp/task.c index b242e7c..d263e54 100644 --- a/libgomp/task.c +++ b/libgomp/task.c @@ -29,6 +29,7 @@ #include "libgomp.h" #include <stdlib.h> #include <string.h> +#include <assert.h> #include "gomp-constants.h" typedef struct gomp_task_depend_entry *hash_entry_type; @@ -86,7 +87,8 @@ gomp_init_task (struct gomp_task *task, struct gomp_task *parent_task, task->dependers = NULL; task->depend_hash = NULL; task->depend_count = 0; - task->detach = false; + task->deferred_p = true; + task->detach_team = NULL; } /* Clean up a task, after completing it. */ @@ -327,12 +329,6 @@ gomp_task_handle_depend (struct gomp_task *task, struct gomp_task *parent, } } -static bool -task_fulfilled_p (struct gomp_task *task) -{ - return gomp_sem_getcount (&task->completion_sem) > 0; -} - /* Called when encountering an explicit task directive. If IF_CLAUSE is false, then we must not delay in executing the task. If UNTIED is true, then the task may be executed by any member of the team. @@ -398,6 +394,7 @@ GOMP_task (void (*fn) (void *), void *data, void (*cpyfn) (void *, void *), || team->task_count > 64 * team->nthreads) { struct gomp_task task; + gomp_sem_t completion_sem; /* If there are depend clauses and earlier deferred sibling tasks with depend clauses, check if there isn't a dependency. If there @@ -414,16 +411,18 @@ GOMP_task (void (*fn) (void *), void *data, void (*cpyfn) (void *, void *), task.final_task = (thr->task && thr->task->final_task) || (flags & GOMP_TASK_FLAG_FINAL); task.priority = priority; + task.deferred_p = false; if ((flags & GOMP_TASK_FLAG_DETACH) != 0) { - task.detach = true; - gomp_sem_init (&task.completion_sem, 0); - *(void **) detach = &task.completion_sem; + gomp_sem_init (&completion_sem, 0); + task.completion_sem = &completion_sem; + *(void **) detach = &task; if (data) - *(void **) data = &task.completion_sem; + *(void **) data = &task; - gomp_debug (0, "New event: %p\n", &task.completion_sem); + gomp_debug (0, "Thread %d: new event: %p\n", + thr->ts.team_id, &task); } if (thr->task) @@ -443,8 +442,11 @@ GOMP_task (void (*fn) (void *), void *data, void (*cpyfn) (void *, void *), else fn (data); - if (task.detach && !task_fulfilled_p (&task)) - gomp_sem_wait (&task.completion_sem); + if ((flags & GOMP_TASK_FLAG_DETACH) != 0) + { + gomp_sem_wait (&completion_sem); + gomp_sem_destroy (&completion_sem); + } /* Access to "children" is normally done inside a task_lock mutex region, but the only way this particular task.children @@ -484,15 +486,16 @@ GOMP_task (void (*fn) (void *), void *data, void (*cpyfn) (void *, void *), task->kind = GOMP_TASK_UNDEFERRED; task->in_tied_task = parent->in_tied_task; task->taskgroup = taskgroup; + task->deferred_p = true; if ((flags & GOMP_TASK_FLAG_DETACH) != 0) { - task->detach = true; - gomp_sem_init (&task->completion_sem, 0); - *(void **) detach = &task->completion_sem; + task->detach_team = team; + + *(void **) detach = task; if (data) - *(void **) data = &task->completion_sem; + *(void **) data = task; - gomp_debug (0, "New event: %p\n", &task->completion_sem); + gomp_debug (0, "Thread %d: new event: %p\n", thr->ts.team_id, task); } thr->task = task; if (cpyfn) @@ -1362,27 +1365,6 @@ gomp_barrier_handle_tasks (gomp_barrier_state_t state) { bool cancelled = false; - /* Look for a queued detached task with a fulfilled completion event - that is ready to finish. */ - child_task = priority_queue_find (PQ_TEAM, &team->task_detach_queue, - task_fulfilled_p); - if (child_task) - { - priority_queue_remove (PQ_TEAM, &team->task_detach_queue, - child_task, MEMMODEL_RELAXED); - --team->task_detach_count; - gomp_debug (0, "thread %d: found task with fulfilled event %p\n", - thr->ts.team_id, &child_task->completion_sem); - - if (to_free) - { - gomp_finish_task (to_free); - free (to_free); - to_free = NULL; - } - goto finish_cancelled; - } - if (!priority_queue_empty_p (&team->task_queue, MEMMODEL_RELAXED)) { bool ignored; @@ -1405,6 +1387,19 @@ gomp_barrier_handle_tasks (gomp_barrier_state_t state) team->task_running_count++; child_task->in_tied_task = true; } + else if (team->task_count == 0 + && gomp_team_barrier_waiting_for_tasks (&team->barrier)) + { + gomp_team_barrier_done (&team->barrier, state); + gomp_mutex_unlock (&team->task_lock); + gomp_team_barrier_wake (&team->barrier, 0); + if (to_free) + { + gomp_finish_task (to_free); + free (to_free); + } + return; + } gomp_mutex_unlock (&team->task_lock); if (do_wake) { @@ -1450,44 +1445,37 @@ gomp_barrier_handle_tasks (gomp_barrier_state_t state) gomp_mutex_lock (&team->task_lock); if (child_task) { - if (child_task->detach && !task_fulfilled_p (child_task)) + if (child_task->detach_team) { - priority_queue_insert (PQ_TEAM, &team->task_detach_queue, - child_task, child_task->priority, - PRIORITY_INSERT_END, - false, false); + assert (child_task->detach_team == team); + child_task->kind = GOMP_TASK_DETACHED; ++team->task_detach_count; - gomp_debug (0, "thread %d: queueing task with event %p\n", - thr->ts.team_id, &child_task->completion_sem); + --team->task_running_count; + gomp_debug (0, + "thread %d: task with event %p finished without " + "completion event fulfilled in team barrier\n", + thr->ts.team_id, child_task); child_task = NULL; + continue; } - else + + finish_cancelled:; + size_t new_tasks + = gomp_task_run_post_handle_depend (child_task, team); + gomp_task_run_post_remove_parent (child_task); + gomp_clear_parent (&child_task->children_queue); + gomp_task_run_post_remove_taskgroup (child_task); + to_free = child_task; + if (!cancelled) + team->task_running_count--; + child_task = NULL; + if (new_tasks > 1) { - finish_cancelled:; - size_t new_tasks - = gomp_task_run_post_handle_depend (child_task, team); - gomp_task_run_post_remove_parent (child_task); - gomp_clear_parent (&child_task->children_queue); - gomp_task_run_post_remove_taskgroup (child_task); - to_free = child_task; - child_task = NULL; - if (!cancelled) - team->task_running_count--; - if (new_tasks > 1) - { - do_wake = team->nthreads - team->task_running_count; - if (do_wake > new_tasks) - do_wake = new_tasks; - } - if (--team->task_count == 0 - && gomp_team_barrier_waiting_for_tasks (&team->barrier)) - { - gomp_team_barrier_done (&team->barrier, state); - gomp_mutex_unlock (&team->task_lock); - gomp_team_barrier_wake (&team->barrier, 0); - gomp_mutex_lock (&team->task_lock); - } + do_wake = team->nthreads - team->task_running_count; + if (do_wake > new_tasks) + do_wake = new_tasks; } + --team->task_count; } } } @@ -1559,7 +1547,8 @@ GOMP_taskwait (void) else { /* All tasks we are waiting for are either running in other - threads, or they are tasks that have not had their + threads, are detached and waiting for the completion event to be + fulfilled, or they are tasks that have not had their dependencies met (so they're not even in the queue). Wait for them. */ if (task->taskwait == NULL) @@ -1614,6 +1603,19 @@ GOMP_taskwait (void) gomp_mutex_lock (&team->task_lock); if (child_task) { + if (child_task->detach_team) + { + assert (child_task->detach_team == team); + child_task->kind = GOMP_TASK_DETACHED; + ++team->task_detach_count; + gomp_debug (0, + "thread %d: task with event %p finished without " + "completion event fulfilled in taskwait\n", + thr->ts.team_id, child_task); + child_task = NULL; + continue; + } + finish_cancelled:; size_t new_tasks = gomp_task_run_post_handle_depend (child_task, team); @@ -2069,6 +2071,19 @@ GOMP_taskgroup_end (void) gomp_mutex_lock (&team->task_lock); if (child_task) { + if (child_task->detach_team) + { + assert (child_task->detach_team == team); + child_task->kind = GOMP_TASK_DETACHED; + ++team->task_detach_count; + gomp_debug (0, + "thread %d: task with event %p finished without " + "completion event fulfilled in taskgroup\n", + thr->ts.team_id, child_task); + child_task = NULL; + continue; + } + finish_cancelled:; size_t new_tasks = gomp_task_run_post_handle_depend (child_task, team); @@ -2402,17 +2417,75 @@ ialias (omp_in_final) void omp_fulfill_event (omp_event_handle_t event) { - gomp_sem_t *sem = (gomp_sem_t *) event; - struct gomp_thread *thr = gomp_thread (); - struct gomp_team *team = thr ? thr->ts.team : NULL; + struct gomp_task *task = (struct gomp_task *) event; + if (!task->deferred_p) + { + if (gomp_sem_getcount (task->completion_sem) > 0) + gomp_fatal ("omp_fulfill_event: %p event already fulfilled!\n", task); - if (gomp_sem_getcount (sem) > 0) - gomp_fatal ("omp_fulfill_event: %p event already fulfilled!\n", sem); + gomp_debug (0, "omp_fulfill_event: %p event for undeferred task\n", + task); + gomp_sem_post (task->completion_sem); + return; + } - gomp_debug (0, "omp_fulfill_event: %p\n", sem); - gomp_sem_post (sem); - if (team) - gomp_team_barrier_wake (&team->barrier, 1); + struct gomp_team *team = __atomic_load_n (&task->detach_team, + MEMMODEL_RELAXED); + if (!team) + gomp_fatal ("omp_fulfill_event: %p event is invalid or has already " + "been fulfilled!\n", task); + + gomp_mutex_lock (&team->task_lock); + if (task->kind != GOMP_TASK_DETACHED) + { + /* The task has not finished running yet. */ + gomp_debug (0, + "omp_fulfill_event: %p event fulfilled for unfinished " + "task\n", task); + __atomic_store_n (&task->detach_team, NULL, MEMMODEL_RELAXED); + gomp_mutex_unlock (&team->task_lock); + return; + } + + gomp_debug (0, "omp_fulfill_event: %p event fulfilled for finished task\n", + task); + size_t new_tasks = gomp_task_run_post_handle_depend (task, team); + gomp_task_run_post_remove_parent (task); + gomp_clear_parent (&task->children_queue); + gomp_task_run_post_remove_taskgroup (task); + team->task_count--; + team->task_detach_count--; + + int do_wake = 0; + bool shackled_thread_p = team == gomp_thread ()->ts.team; + if (new_tasks > 0) + { + /* Wake up threads to run new tasks. */ + do_wake = team->nthreads - team->task_running_count; + if (do_wake > new_tasks) + do_wake = new_tasks; + } + + if (!shackled_thread_p + && !do_wake + && team->task_detach_count == 0 + && gomp_team_barrier_waiting_for_tasks (&team->barrier)) + /* Ensure that at least one thread is woken up to signal that the + barrier can finish. */ + do_wake = 1; + + /* If we are running in an unshackled thread, the team might vanish before + gomp_team_barrier_wake is run if we release the lock first, so keep the + lock for the call in that case. */ + if (shackled_thread_p) + gomp_mutex_unlock (&team->task_lock); + if (do_wake) + gomp_team_barrier_wake (&team->barrier, do_wake); + if (!shackled_thread_p) + gomp_mutex_unlock (&team->task_lock); + + gomp_finish_task (task); + free (task); } ialias (omp_fulfill_event) diff --git a/libgomp/team.c b/libgomp/team.c index 0f3707c..9662234 100644 --- a/libgomp/team.c +++ b/libgomp/team.c @@ -206,7 +206,6 @@ gomp_new_team (unsigned nthreads) team->work_share_cancelled = 0; team->team_cancelled = 0; - priority_queue_init (&team->task_detach_queue); team->task_detach_count = 0; return team; @@ -224,7 +223,6 @@ free_team (struct gomp_team *team) gomp_barrier_destroy (&team->barrier); gomp_mutex_destroy (&team->task_lock); priority_queue_free (&team->task_queue); - priority_queue_free (&team->task_detach_queue); team_free (team); } diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-1.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-1.c index 8583e37..14932b0 100644 --- a/libgomp/testsuite/libgomp.c-c++-common/task-detach-1.c +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-1.c @@ -14,10 +14,10 @@ int main (void) #pragma omp parallel #pragma omp single { - #pragma omp task detach(detach_event1) + #pragma omp task detach (detach_event1) x++; - #pragma omp task detach(detach_event2) + #pragma omp task detach (detach_event2) { y++; omp_fulfill_event (detach_event1); diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-10.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-10.c new file mode 100644 index 0000000..10d6746 --- /dev/null +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-10.c @@ -0,0 +1,45 @@ +/* { dg-do run } */ + +#include <omp.h> +#include <assert.h> + +/* Test tasks with detach clause on an offload device. Each device + thread spawns off a chain of tasks in a taskgroup, that can then + be executed by any available thread. */ + +int main (void) +{ + int x = 0, y = 0, z = 0; + int thread_count; + omp_event_handle_t detach_event1, detach_event2; + + #pragma omp target map (tofrom: x, y, z) map (from: thread_count) + #pragma omp parallel private (detach_event1, detach_event2) + #pragma omp taskgroup + { + #pragma omp single + thread_count = omp_get_num_threads (); + + #pragma omp task detach (detach_event1) untied + #pragma omp atomic update + x++; + + #pragma omp task detach (detach_event2) untied + { + #pragma omp atomic update + y++; + omp_fulfill_event (detach_event1); + } + + #pragma omp task untied + { + #pragma omp atomic update + z++; + omp_fulfill_event (detach_event2); + } + } + + assert (x == thread_count); + assert (y == thread_count); + assert (z == thread_count); +} diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-11.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-11.c new file mode 100644 index 0000000..dd002dc --- /dev/null +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-11.c @@ -0,0 +1,13 @@ +/* { dg-do run } */ + +#include <omp.h> + +/* Test the detach clause when the task is undeferred. */ + +int main (void) +{ + omp_event_handle_t event; + + #pragma omp task detach (event) + omp_fulfill_event (event); +} diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-2.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-2.c index 943ac2a..3e33c40 100644 --- a/libgomp/testsuite/libgomp.c-c++-common/task-detach-2.c +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-2.c @@ -12,13 +12,13 @@ int main (void) omp_event_handle_t detach_event1, detach_event2; int x = 0, y = 0, z = 0; - #pragma omp parallel num_threads(1) + #pragma omp parallel num_threads (1) #pragma omp single { - #pragma omp task detach(detach_event1) + #pragma omp task detach (detach_event1) x++; - #pragma omp task detach(detach_event2) + #pragma omp task detach (detach_event2) { y++; omp_fulfill_event (detach_event1); diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-3.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-3.c index 2609fb1..c85857d 100644 --- a/libgomp/testsuite/libgomp.c-c++-common/task-detach-3.c +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-3.c @@ -14,16 +14,16 @@ int main (void) #pragma omp parallel #pragma omp single { - #pragma omp task depend(out:dep) detach(detach_event) + #pragma omp task depend (out:dep) detach (detach_event) x++; #pragma omp task { y++; - omp_fulfill_event(detach_event); + omp_fulfill_event (detach_event); } - #pragma omp task depend(in:dep) + #pragma omp task depend (in:dep) z++; } diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-4.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-4.c index eeb9554..cd0d2b3 100644 --- a/libgomp/testsuite/libgomp.c-c++-common/task-detach-4.c +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-4.c @@ -14,10 +14,10 @@ int main (void) #pragma omp parallel #pragma omp single - #pragma omp task detach(detach_event) + #pragma omp task detach (detach_event) { x++; - omp_fulfill_event(detach_event); + omp_fulfill_event (detach_event); } assert (x == 1); diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-5.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-5.c index 5a01517..382f377 100644 --- a/libgomp/testsuite/libgomp.c-c++-common/task-detach-5.c +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-5.c @@ -12,16 +12,16 @@ int main (void) int thread_count; omp_event_handle_t detach_event1, detach_event2; - #pragma omp parallel firstprivate(detach_event1, detach_event2) + #pragma omp parallel private (detach_event1, detach_event2) { #pragma omp single - thread_count = omp_get_num_threads(); + thread_count = omp_get_num_threads (); - #pragma omp task detach(detach_event1) untied + #pragma omp task detach (detach_event1) untied #pragma omp atomic update x++; - #pragma omp task detach(detach_event2) untied + #pragma omp task detach (detach_event2) untied { #pragma omp atomic update y++; diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-6.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-6.c index b5f68cc..e5c2291 100644 --- a/libgomp/testsuite/libgomp.c-c++-common/task-detach-6.c +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-6.c @@ -13,11 +13,11 @@ int main (void) int thread_count; omp_event_handle_t detach_event1, detach_event2; - #pragma omp target map(tofrom: x, y, z) map(from: thread_count) - #pragma omp parallel firstprivate(detach_event1, detach_event2) + #pragma omp target map (tofrom: x, y, z) map (from: thread_count) + #pragma omp parallel private (detach_event1, detach_event2) { #pragma omp single - thread_count = omp_get_num_threads(); + thread_count = omp_get_num_threads (); #pragma omp task detach(detach_event1) untied #pragma omp atomic update @@ -36,8 +36,6 @@ int main (void) z++; omp_fulfill_event (detach_event2); } - - #pragma omp taskwait } assert (x == thread_count); diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-7.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-7.c new file mode 100644 index 0000000..3f025d6 --- /dev/null +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-7.c @@ -0,0 +1,45 @@ +/* { dg-do run } */ + +#include <omp.h> +#include <assert.h> + +/* Test tasks with detach clause. Each thread spawns off a chain of tasks, + that can then be executed by any available thread. Each thread uses + taskwait to wait for the child tasks to complete. */ + +int main (void) +{ + int x = 0, y = 0, z = 0; + int thread_count; + omp_event_handle_t detach_event1, detach_event2; + + #pragma omp parallel private (detach_event1, detach_event2) + { + #pragma omp single + thread_count = omp_get_num_threads (); + + #pragma omp task detach (detach_event1) untied + #pragma omp atomic update + x++; + + #pragma omp task detach (detach_event2) untied + { + #pragma omp atomic update + y++; + omp_fulfill_event (detach_event1); + } + + #pragma omp task untied + { + #pragma omp atomic update + z++; + omp_fulfill_event (detach_event2); + } + + #pragma omp taskwait + } + + assert (x == thread_count); + assert (y == thread_count); + assert (z == thread_count); +} diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-8.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-8.c new file mode 100644 index 0000000..6f77f12 --- /dev/null +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-8.c @@ -0,0 +1,47 @@ +/* { dg-do run } */ + +#include <omp.h> +#include <assert.h> + +/* Test tasks with detach clause on an offload device. Each device + thread spawns off a chain of tasks, that can then be executed by + any available thread. Each thread uses taskwait to wait for the + child tasks to complete. */ + +int main (void) +{ + int x = 0, y = 0, z = 0; + int thread_count; + omp_event_handle_t detach_event1, detach_event2; + + #pragma omp target map (tofrom: x, y, z) map (from: thread_count) + #pragma omp parallel private (detach_event1, detach_event2) + { + #pragma omp single + thread_count = omp_get_num_threads (); + + #pragma omp task detach (detach_event1) untied + #pragma omp atomic update + x++; + + #pragma omp task detach (detach_event2) untied + { + #pragma omp atomic update + y++; + omp_fulfill_event (detach_event1); + } + + #pragma omp task untied + { + #pragma omp atomic update + z++; + omp_fulfill_event (detach_event2); + } + + #pragma omp taskwait + } + + assert (x == thread_count); + assert (y == thread_count); + assert (z == thread_count); +} diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-9.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-9.c new file mode 100644 index 0000000..5316ca5 --- /dev/null +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-9.c @@ -0,0 +1,43 @@ +/* { dg-do run } */ + +#include <omp.h> +#include <assert.h> + +/* Test tasks with detach clause. Each thread spawns off a chain of tasks + in a taskgroup, that can then be executed by any available thread. */ + +int main (void) +{ + int x = 0, y = 0, z = 0; + int thread_count; + omp_event_handle_t detach_event1, detach_event2; + + #pragma omp parallel private (detach_event1, detach_event2) + #pragma omp taskgroup + { + #pragma omp single + thread_count = omp_get_num_threads (); + + #pragma omp task detach (detach_event1) untied + #pragma omp atomic update + x++; + + #pragma omp task detach (detach_event2) untied + { + #pragma omp atomic update + y++; + omp_fulfill_event (detach_event1); + } + + #pragma omp task untied + { + #pragma omp atomic update + z++; + omp_fulfill_event (detach_event2); + } + } + + assert (x == thread_count); + assert (y == thread_count); + assert (z == thread_count); +} diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-1.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-1.f90 index 217bf65..c53b1ca 100644 --- a/libgomp/testsuite/libgomp.fortran/task-detach-1.f90 +++ b/libgomp/testsuite/libgomp.fortran/task-detach-1.f90 @@ -11,11 +11,11 @@ program task_detach_1 !$omp parallel !$omp single - !$omp task detach(detach_event1) + !$omp task detach (detach_event1) x = x + 1 !$omp end task - !$omp task detach(detach_event2) + !$omp task detach (detach_event2) y = y + 1 call omp_fulfill_event (detach_event1) !$omp end task diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-10.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-10.f90 new file mode 100644 index 0000000..61f0ea8 --- /dev/null +++ b/libgomp/testsuite/libgomp.fortran/task-detach-10.f90 @@ -0,0 +1,44 @@ +! { dg-do run } + +! Test tasks with detach clause on an offload device. Each device +! thread spawns off a chain of tasks in a taskgroup, that can then +! be executed by any available thread. + +program task_detach_10 + use omp_lib + + integer (kind=omp_event_handle_kind) :: detach_event1, detach_event2 + integer :: x = 0, y = 0, z = 0 + integer :: thread_count + + !$omp target map (tofrom: x, y, z) map (from: thread_count) + !$omp parallel private (detach_event1, detach_event2) + !$omp taskgroup + !$omp single + thread_count = omp_get_num_threads () + !$omp end single + + !$omp task detach (detach_event1) untied + !$omp atomic update + x = x + 1 + !$omp end task + + !$omp task detach (detach_event2) untied + !$omp atomic update + y = y + 1 + call omp_fulfill_event (detach_event1) + !$omp end task + + !$omp task untied + !$omp atomic update + z = z + 1 + call omp_fulfill_event (detach_event2) + !$omp end task + !$omp end taskgroup + !$omp end parallel + !$omp end target + + if (x /= thread_count) stop 1 + if (y /= thread_count) stop 2 + if (z /= thread_count) stop 3 +end program diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-11.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-11.f90 new file mode 100644 index 0000000..b33baff --- /dev/null +++ b/libgomp/testsuite/libgomp.fortran/task-detach-11.f90 @@ -0,0 +1,13 @@ +! { dg-do run } + +! Test the detach clause when the task is undeferred. + +program task_detach_11 + use omp_lib + + integer (kind=omp_event_handle_kind) :: detach_event + + !$omp task detach (detach_event) + call omp_fulfill_event (detach_event) + !$omp end task +end program diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-2.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-2.f90 index ecb4829..68e3ff2 100644 --- a/libgomp/testsuite/libgomp.fortran/task-detach-2.f90 +++ b/libgomp/testsuite/libgomp.fortran/task-detach-2.f90 @@ -10,13 +10,13 @@ program task_detach_2 integer (kind=omp_event_handle_kind) :: detach_event1, detach_event2 integer :: x = 0, y = 0, z = 0 - !$omp parallel num_threads(1) + !$omp parallel num_threads (1) !$omp single - !$omp task detach(detach_event1) + !$omp task detach (detach_event1) x = x + 1 !$omp end task - !$omp task detach(detach_event2) + !$omp task detach (detach_event2) y = y + 1 call omp_fulfill_event (detach_event1) !$omp end task diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-3.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-3.f90 index bdf93a5..5ac68d5 100644 --- a/libgomp/testsuite/libgomp.fortran/task-detach-3.f90 +++ b/libgomp/testsuite/libgomp.fortran/task-detach-3.f90 @@ -12,16 +12,16 @@ program task_detach_3 !$omp parallel !$omp single - !$omp task depend(out:dep) detach(detach_event) + !$omp task depend (out:dep) detach (detach_event) x = x + 1 !$omp end task !$omp task y = y + 1 - call omp_fulfill_event(detach_event) + call omp_fulfill_event (detach_event) !$omp end task - !$omp task depend(in:dep) + !$omp task depend (in:dep) z = z + 1 !$omp end task !$omp end single diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-4.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-4.f90 index 6d0843c..159624c 100644 --- a/libgomp/testsuite/libgomp.fortran/task-detach-4.f90 +++ b/libgomp/testsuite/libgomp.fortran/task-detach-4.f90 @@ -11,9 +11,9 @@ program task_detach_4 !$omp parallel !$omp single - !$omp task detach(detach_event) + !$omp task detach (detach_event) x = x + 1 - call omp_fulfill_event(detach_event) + call omp_fulfill_event (detach_event) !$omp end task !$omp end single !$omp end parallel diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-5.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-5.f90 index 955d687..95bd132 100644 --- a/libgomp/testsuite/libgomp.fortran/task-detach-5.f90 +++ b/libgomp/testsuite/libgomp.fortran/task-detach-5.f90 @@ -10,17 +10,17 @@ program task_detach_5 integer :: x = 0, y = 0, z = 0 integer :: thread_count - !$omp parallel firstprivate(detach_event1, detach_event2) + !$omp parallel private (detach_event1, detach_event2) !$omp single - thread_count = omp_get_num_threads() + thread_count = omp_get_num_threads () !$omp end single - !$omp task detach(detach_event1) untied + !$omp task detach (detach_event1) untied !$omp atomic update x = x + 1 !$omp end task - !$omp task detach(detach_event2) untied + !$omp task detach (detach_event2) untied !$omp atomic update y = y + 1 call omp_fulfill_event (detach_event1); diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-6.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-6.f90 index 0fe2155..b2c476f 100644 --- a/libgomp/testsuite/libgomp.fortran/task-detach-6.f90 +++ b/libgomp/testsuite/libgomp.fortran/task-detach-6.f90 @@ -11,30 +11,28 @@ program task_detach_6 integer :: x = 0, y = 0, z = 0 integer :: thread_count - !$omp target map(tofrom: x, y, z) map(from: thread_count) - !$omp parallel firstprivate(detach_event1, detach_event2) + !$omp target map (tofrom: x, y, z) map (from: thread_count) + !$omp parallel private (detach_event1, detach_event2) !$omp single - thread_count = omp_get_num_threads() + thread_count = omp_get_num_threads () !$omp end single - !$omp task detach(detach_event1) untied + !$omp task detach (detach_event1) untied !$omp atomic update x = x + 1 !$omp end task - !$omp task detach(detach_event2) untied + !$omp task detach (detach_event2) untied !$omp atomic update y = y + 1 - call omp_fulfill_event (detach_event1); + call omp_fulfill_event (detach_event1) !$omp end task !$omp task untied !$omp atomic update z = z + 1 - call omp_fulfill_event (detach_event2); + call omp_fulfill_event (detach_event2) !$omp end task - - !$omp taskwait !$omp end parallel !$omp end target diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-7.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-7.f90 new file mode 100644 index 0000000..32e715e --- /dev/null +++ b/libgomp/testsuite/libgomp.fortran/task-detach-7.f90 @@ -0,0 +1,42 @@ +! { dg-do run } + +! Test tasks with detach clause. Each thread spawns off a chain of tasks, +! that can then be executed by any available thread. Each thread uses +! taskwait to wait for the child tasks to complete. + +program task_detach_7 + use omp_lib + + integer (kind=omp_event_handle_kind) :: detach_event1, detach_event2 + integer :: x = 0, y = 0, z = 0 + integer :: thread_count + + !$omp parallel private (detach_event1, detach_event2) + !$omp single + thread_count = omp_get_num_threads() + !$omp end single + + !$omp task detach (detach_event1) untied + !$omp atomic update + x = x + 1 + !$omp end task + + !$omp task detach (detach_event2) untied + !$omp atomic update + y = y + 1 + call omp_fulfill_event (detach_event1) + !$omp end task + + !$omp task untied + !$omp atomic update + z = z + 1 + call omp_fulfill_event (detach_event2) + !$omp end task + + !$omp taskwait + !$omp end parallel + + if (x /= thread_count) stop 1 + if (y /= thread_count) stop 2 + if (z /= thread_count) stop 3 +end program diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-8.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-8.f90 new file mode 100644 index 0000000..e760eab --- /dev/null +++ b/libgomp/testsuite/libgomp.fortran/task-detach-8.f90 @@ -0,0 +1,45 @@ +! { dg-do run } + +! Test tasks with detach clause on an offload device. Each device +! thread spawns off a chain of tasks, that can then be executed by +! any available thread. Each thread uses taskwait to wait for the +! child tasks to complete. + +program task_detach_8 + use omp_lib + + integer (kind=omp_event_handle_kind) :: detach_event1, detach_event2 + integer :: x = 0, y = 0, z = 0 + integer :: thread_count + + !$omp target map (tofrom: x, y, z) map (from: thread_count) + !$omp parallel private (detach_event1, detach_event2) + !$omp single + thread_count = omp_get_num_threads () + !$omp end single + + !$omp task detach (detach_event1) untied + !$omp atomic update + x = x + 1 + !$omp end task + + !$omp task detach (detach_event2) untied + !$omp atomic update + y = y + 1 + call omp_fulfill_event (detach_event1) + !$omp end task + + !$omp task untied + !$omp atomic update + z = z + 1 + call omp_fulfill_event (detach_event2) + !$omp end task + + !$omp taskwait + !$omp end parallel + !$omp end target + + if (x /= thread_count) stop 1 + if (y /= thread_count) stop 2 + if (z /= thread_count) stop 3 +end program diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-9.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-9.f90 new file mode 100644 index 0000000..540c6de --- /dev/null +++ b/libgomp/testsuite/libgomp.fortran/task-detach-9.f90 @@ -0,0 +1,41 @@ +! { dg-do run } + +! Test tasks with detach clause. Each thread spawns off a chain of tasks +! in a taskgroup, that can then be executed by any available thread. + +program task_detach_9 + use omp_lib + + integer (kind=omp_event_handle_kind) :: detach_event1, detach_event2 + integer :: x = 0, y = 0, z = 0 + integer :: thread_count + + !$omp parallel private (detach_event1, detach_event2) + !$omp taskgroup + !$omp single + thread_count = omp_get_num_threads () + !$omp end single + + !$omp task detach (detach_event1) untied + !$omp atomic update + x = x + 1 + !$omp end task + + !$omp task detach (detach_event2) untied + !$omp atomic update + y = y + 1 + call omp_fulfill_event (detach_event1); + !$omp end task + + !$omp task untied + !$omp atomic update + z = z + 1 + call omp_fulfill_event (detach_event2); + !$omp end task + !$omp end taskgroup + !$omp end parallel + + if (x /= thread_count) stop 1 + if (y /= thread_count) stop 2 + if (z /= thread_count) stop 3 +end program
On Thu, Feb 25, 2021 at 04:21:31PM +0000, Kwok Cheung Yeung wrote: > Reversing the order reduces the hole to 3 bytes: > > size_t num_dependees; /* 80 8 */ > union { > gomp_sem_t * completion_sem; /* 88 8 */ > struct gomp_team * detach_team; /* 88 8 */ > }; /* 88 8 */ > _Bool deferred_p; /* 96 1 */ > > /* XXX 3 bytes hole, try to pack */ > > int priority; /* 100 4 */ > > If we were really determined to get rid of the hole, we could stash > deferred_p in the least-significant bit of the pointer union, but I think Sorry, indeed, I was thinking about how it would be packed after priority, not before it but putting it in between priority and the related prio queues is undesirable. So union, deferred_p, priority is the right order. > > I think you can move task->deferred_p into the if stmt. > > That can be done (since the code for detach is currently the only thing > using it), but I think it would be better to have deferred_p always have the > right value, regardless of whether or not it is used? Otherwise that might > lead to some confusion if it is later used by something else. Ok either way. > I will get this committed later if the regression tests finish with no surprises. Two more nits below. > @@ -86,7 +87,8 @@ gomp_init_task (struct gomp_task *task, struct gomp_task *parent_task, > task->dependers = NULL; > task->depend_hash = NULL; > task->depend_count = 0; > - task->detach = false; > + task->deferred_p = true; > + task->detach_team = NULL; > } Please initialize deferred_p to false rather than true, because gomp_init_task is called in many places and except for that one spot in GOMP_task (and one in taskloop.c) the tasks are undeferred (e.g. the implicit tasks in parallel or the initial one etc.). And maybe also reorder the fields initialized in there to match the order of increasing field offsets. > @@ -414,16 +411,18 @@ GOMP_task (void (*fn) (void *), void *data, void (*cpyfn) (void *, void *), > task.final_task = (thr->task && thr->task->final_task) > || (flags & GOMP_TASK_FLAG_FINAL); > task.priority = priority; > + task.deferred_p = false; And then this shouldn't be here, gomp_init_task has already initialized it that way. Jakub
Hi! On 2021-02-23T22:52:38+0100, Jakub Jelinek via Gcc-patches <gcc-patches@gcc.gnu.org> wrote: > On Tue, Feb 23, 2021 at 09:43:51PM +0000, Kwok Cheung Yeung wrote: >> On 19/02/2021 7:12 pm, Kwok Cheung Yeung wrote: >> > I have included the current state of my patch. All task-detach-* tests >> > pass when executed without offloading or with offloading to GCN, but >> > with offloading to Nvidia, task-detach-6.* hangs consistently but >> > everything else passes (probably because of the missing >> > gomp_team_barrier_done?). >> >> It looks like the hang has nothing to do with the detach patch - this hangs >> consistently for me when offloaded to NVPTX: >> >> #include <omp.h> >> >> int main (void) >> { >> #pragma omp target >> #pragma omp parallel >> #pragma omp task >> ; >> } >> >> This doesn't hang when offloaded to GCN or the host device, or if >> num_threads(1) is specified on the omp parallel. So, I reproduced this the hard way; <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98738#c13> :-/ Please always file issues when you run into such things. I've now filed PR99555 "[OpenMP/nvptx] Execution-time hang for simple nested OpenMP 'target'/'parallel'/'task' constructs". > Then it can be solved separately, I'll try to have a look if I see something > bad from the dumps, but I admit I don't have much experience with debugging > NVPTX offloaded code... Any luck? Until this gets resolved properly, OK to push something like the attached (currently testing) "Avoid OpenMP/nvptx execution-time hangs for simple nested OpenMP 'target'/'parallel'/'task' constructs [PR99555]"? Grüße Thomas ----------------- Mentor Graphics (Deutschland) GmbH, Arnulfstrasse 201, 80634 München Registergericht München HRB 106955, Geschäftsführer: Thomas Heurung, Frank Thürauf
Hi! On 2021-03-11T17:52:55+0100, I wrote: > On 2021-02-23T22:52:38+0100, Jakub Jelinek via Gcc-patches <gcc-patches@gcc.gnu.org> wrote: >> On Tue, Feb 23, 2021 at 09:43:51PM +0000, Kwok Cheung Yeung wrote: >>> On 19/02/2021 7:12 pm, Kwok Cheung Yeung wrote: >>> > I have included the current state of my patch. All task-detach-* tests >>> > pass when executed without offloading or with offloading to GCN, but >>> > with offloading to Nvidia, task-detach-6.* hangs consistently but >>> > everything else passes (probably because of the missing >>> > gomp_team_barrier_done?). >>> >>> It looks like the hang has nothing to do with the detach patch - this hangs >>> consistently for me when offloaded to NVPTX: >>> >>> #include <omp.h> >>> >>> int main (void) >>> { >>> #pragma omp target >>> #pragma omp parallel >>> #pragma omp task >>> ; >>> } >>> >>> This doesn't hang when offloaded to GCN or the host device, or if >>> num_threads(1) is specified on the omp parallel. > > So, I reproduced this the hard way; > <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98738#c13> :-/ > > Please always file issues when you run into such things. I've now filed > PR99555 "[OpenMP/nvptx] Execution-time hang for simple nested OpenMP > 'target'/'parallel'/'task' constructs". > >> Then it can be solved separately, I'll try to have a look if I see something >> bad from the dumps, but I admit I don't have much experience with debugging >> NVPTX offloaded code... > > Any luck? > > > Until this gets resolved properly, OK to push something like the attached > (currently testing) "Avoid OpenMP/nvptx execution-time hangs for simple > nested OpenMP 'target'/'parallel'/'task' constructs [PR99555]"? As posted, I've now pushed "Avoid OpenMP/nvptx execution-time hangs for simple nested OpenMP 'target'/'parallel'/'task' constructs [PR99555]" to master branch in commit d99111fd8e12deffdd9a965ce17e8a760d531ec3, see attached. "... awaiting proper resolution, of course." Grüße Thomas ----------------- Mentor Graphics (Deutschland) GmbH, Arnulfstrasse 201, 80634 München Registergericht München HRB 106955, Geschäftsführer: Thomas Heurung, Frank Thürauf
Hi! On 2021-03-25T12:02:15+0100, I wrote: > On 2021-03-11T17:52:55+0100, I wrote: >> On 2021-02-23T22:52:38+0100, Jakub Jelinek via Gcc-patches <gcc-patches@gcc.gnu.org> wrote: >>> On Tue, Feb 23, 2021 at 09:43:51PM +0000, Kwok Cheung Yeung wrote: >>>> On 19/02/2021 7:12 pm, Kwok Cheung Yeung wrote: >>>> > I have included the current state of my patch. All task-detach-* tests >>>> > pass when executed without offloading or with offloading to GCN, but >>>> > with offloading to Nvidia, task-detach-6.* hangs consistently but >>>> > everything else passes (probably because of the missing >>>> > gomp_team_barrier_done?). >>>> >>>> It looks like the hang has nothing to do with the detach patch - this hangs >>>> consistently for me when offloaded to NVPTX: >>>> >>>> #include <omp.h> >>>> >>>> int main (void) >>>> { >>>> #pragma omp target >>>> #pragma omp parallel >>>> #pragma omp task >>>> ; >>>> } >>>> >>>> This doesn't hang when offloaded to GCN or the host device, or if >>>> num_threads(1) is specified on the omp parallel. >> >> So, I reproduced this the hard way; >> <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98738#c13> :-/ >> >> Please always file issues when you run into such things. I've now filed >> PR99555 "[OpenMP/nvptx] Execution-time hang for simple nested OpenMP >> 'target'/'parallel'/'task' constructs". >> >>> Then it can be solved separately, I'll try to have a look if I see something >>> bad from the dumps, but I admit I don't have much experience with debugging >>> NVPTX offloaded code... >> >> Any luck? >> >> >> Until this gets resolved properly, OK to push something like the attached >> (currently testing) "Avoid OpenMP/nvptx execution-time hangs for simple >> nested OpenMP 'target'/'parallel'/'task' constructs [PR99555]"? > > As posted, I've now pushed "Avoid OpenMP/nvptx execution-time hangs for > simple nested OpenMP 'target'/'parallel'/'task' constructs [PR99555]" to > master branch in commit d99111fd8e12deffdd9a965ce17e8a760d531ec3, see > attached. "... awaiting proper resolution, of course." > + if (on_device_arch_nvptx ()) > + __builtin_abort (); //TODO Until resolved, skip, with error status. Actually, we can do better: do try to execute this trivial OpenMP code (expected to complete in no time), but for nvptx offloading "make sure that we exit quickly, with error status", and XFAIL that. So that we'll get XFAIL -> XPASS when this starts to work for nvptx offloading. Is that attached "XFAIL OpenMP/nvptx execution-time hangs for simple nested OpenMP 'target'/'parallel'/'task' constructs [PR99555]" OK to push? There are other testcases that '#include <unistd.h>' -- do we have to worry about 'alarm' not being available in some configurations where the libgomp testsuite executes (and OpenMP 'target' doesn't already fail for other reasons)? Grüße Thomas ----------------- Mentor Graphics (Deutschland) GmbH, Arnulfstrasse 201, 80634 München Registergericht München HRB 106955, Geschäftsführer: Thomas Heurung, Frank Thürauf
Hi! On 2021-04-09T13:00:39+0200, I wrote: > On 2021-03-25T12:02:15+0100, I wrote: >> On 2021-03-11T17:52:55+0100, I wrote: >>> On 2021-02-23T22:52:38+0100, Jakub Jelinek via Gcc-patches <gcc-patches@gcc.gnu.org> wrote: >>>> On Tue, Feb 23, 2021 at 09:43:51PM +0000, Kwok Cheung Yeung wrote: >>>>> On 19/02/2021 7:12 pm, Kwok Cheung Yeung wrote: >>>>> > I have included the current state of my patch. All task-detach-* tests >>>>> > pass when executed without offloading or with offloading to GCN, but >>>>> > with offloading to Nvidia, task-detach-6.* hangs consistently but >>>>> > everything else passes (probably because of the missing >>>>> > gomp_team_barrier_done?). >>>>> >>>>> It looks like the hang has nothing to do with the detach patch - this hangs >>>>> consistently for me when offloaded to NVPTX: >>>>> >>>>> #include <omp.h> >>>>> >>>>> int main (void) >>>>> { >>>>> #pragma omp target >>>>> #pragma omp parallel >>>>> #pragma omp task >>>>> ; >>>>> } >>>>> >>>>> This doesn't hang when offloaded to GCN or the host device, or if >>>>> num_threads(1) is specified on the omp parallel. >>> >>> So, I reproduced this the hard way; >>> <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98738#c13> :-/ >>> >>> Please always file issues when you run into such things. I've now filed >>> PR99555 "[OpenMP/nvptx] Execution-time hang for simple nested OpenMP >>> 'target'/'parallel'/'task' constructs". >>> >>>> Then it can be solved separately, I'll try to have a look if I see something >>>> bad from the dumps, but I admit I don't have much experience with debugging >>>> NVPTX offloaded code... >>> >>> Any luck? >>> >>> >>> Until this gets resolved properly, OK to push something like the attached >>> (currently testing) "Avoid OpenMP/nvptx execution-time hangs for simple >>> nested OpenMP 'target'/'parallel'/'task' constructs [PR99555]"? >> >> As posted, I've now pushed "Avoid OpenMP/nvptx execution-time hangs for >> simple nested OpenMP 'target'/'parallel'/'task' constructs [PR99555]" to >> master branch in commit d99111fd8e12deffdd9a965ce17e8a760d531ec3, see >> attached. "... awaiting proper resolution, of course." > >> + if (on_device_arch_nvptx ()) >> + __builtin_abort (); //TODO Until resolved, skip, with error status. > > Actually, we can do better: do try to execute this trivial OpenMP code > (expected to complete in no time), but for nvptx offloading "make sure > that we exit quickly, with error status", and XFAIL that. So that we'll > get XFAIL -> XPASS when this starts to work for nvptx offloading. Pushed "XFAIL OpenMP/nvptx execution-time hangs for simple nested OpenMP 'target'/'parallel'/'task' constructs [PR99555]" to master branch in commit 4dd9e1c541e0eb921d62c8652c854b1259e56aac, see attached. Grüße Thomas ----------------- Mentor Graphics (Deutschland) GmbH, Arnulfstrasse 201, 80634 München Registergericht München HRB 106955, Geschäftsführer: Thomas Heurung, Frank Thürauf
diff --git a/libgomp/libgomp.h b/libgomp/libgomp.h index b4d0c93..90a6f02 100644 --- a/libgomp/libgomp.h +++ b/libgomp/libgomp.h @@ -481,7 +481,10 @@ enum gomp_task_kind but not yet completed. Once that completes, they will be readded into the queues as GOMP_TASK_WAITING in order to perform the var unmapping. */ - GOMP_TASK_ASYNC_RUNNING + GOMP_TASK_ASYNC_RUNNING, + /* Task that has finished executing but is waiting for its + completion event to be fulfilled. */ + GOMP_TASK_DETACHED }; struct gomp_task_depend_entry @@ -545,8 +548,14 @@ struct gomp_task entries and the gomp_task in which they reside. */ struct priority_node pnode[3]; - bool detach; - gomp_sem_t completion_sem; + union { + /* Valid only if kind == GOMP_TASK_UNDEFERRED. */ + gomp_sem_t completion_sem; + /* Valid for other values of kind. Set to the team that executes the + task if the task is detached and the completion event has yet to be + fulfilled. */ + struct gomp_team *detach_team; + }; struct gomp_task_icv icv; void (*fn) (void *); @@ -688,8 +697,7 @@ struct gomp_team int work_share_cancelled; int team_cancelled; - /* Tasks waiting for their completion event to be fulfilled. */ - struct priority_queue task_detach_queue; + /* Number of tasks waiting for their completion event to be fulfilled. */ unsigned int task_detach_count; /* This array contains structures for implicit tasks. */ diff --git a/libgomp/task.c b/libgomp/task.c index b242e7c..399e18b 100644 --- a/libgomp/task.c +++ b/libgomp/task.c @@ -29,6 +29,7 @@ #include "libgomp.h" #include <stdlib.h> #include <string.h> +#include <assert.h> #include "gomp-constants.h" typedef struct gomp_task_depend_entry *hash_entry_type; @@ -86,7 +87,7 @@ gomp_init_task (struct gomp_task *task, struct gomp_task *parent_task, task->dependers = NULL; task->depend_hash = NULL; task->depend_count = 0; - task->detach = false; + task->detach_team = NULL; } /* Clean up a task, after completing it. */ @@ -327,12 +328,6 @@ gomp_task_handle_depend (struct gomp_task *task, struct gomp_task *parent, } } -static bool -task_fulfilled_p (struct gomp_task *task) -{ - return gomp_sem_getcount (&task->completion_sem) > 0; -} - /* Called when encountering an explicit task directive. If IF_CLAUSE is false, then we must not delay in executing the task. If UNTIED is true, then the task may be executed by any member of the team. @@ -417,13 +412,13 @@ GOMP_task (void (*fn) (void *), void *data, void (*cpyfn) (void *, void *), if ((flags & GOMP_TASK_FLAG_DETACH) != 0) { - task.detach = true; gomp_sem_init (&task.completion_sem, 0); - *(void **) detach = &task.completion_sem; + *(void **) detach = &task; if (data) - *(void **) data = &task.completion_sem; + *(void **) data = &task; - gomp_debug (0, "New event: %p\n", &task.completion_sem); + gomp_debug (0, "Thread %d: new event: %p\n", + thr->ts.team_id, &task); } if (thr->task) @@ -443,7 +438,7 @@ GOMP_task (void (*fn) (void *), void *data, void (*cpyfn) (void *, void *), else fn (data); - if (task.detach && !task_fulfilled_p (&task)) + if ((flags & GOMP_TASK_FLAG_DETACH) != 0 && detach) gomp_sem_wait (&task.completion_sem); /* Access to "children" is normally done inside a task_lock @@ -481,18 +476,17 @@ GOMP_task (void (*fn) (void *), void *data, void (*cpyfn) (void *, void *), & ~(uintptr_t) (arg_align - 1)); gomp_init_task (task, parent, gomp_icv (false)); task->priority = priority; - task->kind = GOMP_TASK_UNDEFERRED; task->in_tied_task = parent->in_tied_task; task->taskgroup = taskgroup; if ((flags & GOMP_TASK_FLAG_DETACH) != 0) { - task->detach = true; - gomp_sem_init (&task->completion_sem, 0); - *(void **) detach = &task->completion_sem; + task->detach_team = team; + + *(void **) detach = task; if (data) - *(void **) data = &task->completion_sem; + *(void **) data = task; - gomp_debug (0, "New event: %p\n", &task->completion_sem); + gomp_debug (0, "Thread %d: new event: %p\n", thr->ts.team_id, task); } thr->task = task; if (cpyfn) @@ -1362,27 +1356,6 @@ gomp_barrier_handle_tasks (gomp_barrier_state_t state) { bool cancelled = false; - /* Look for a queued detached task with a fulfilled completion event - that is ready to finish. */ - child_task = priority_queue_find (PQ_TEAM, &team->task_detach_queue, - task_fulfilled_p); - if (child_task) - { - priority_queue_remove (PQ_TEAM, &team->task_detach_queue, - child_task, MEMMODEL_RELAXED); - --team->task_detach_count; - gomp_debug (0, "thread %d: found task with fulfilled event %p\n", - thr->ts.team_id, &child_task->completion_sem); - - if (to_free) - { - gomp_finish_task (to_free); - free (to_free); - to_free = NULL; - } - goto finish_cancelled; - } - if (!priority_queue_empty_p (&team->task_queue, MEMMODEL_RELAXED)) { bool ignored; @@ -1450,43 +1423,43 @@ gomp_barrier_handle_tasks (gomp_barrier_state_t state) gomp_mutex_lock (&team->task_lock); if (child_task) { - if (child_task->detach && !task_fulfilled_p (child_task)) + if (child_task->detach_team) { - priority_queue_insert (PQ_TEAM, &team->task_detach_queue, - child_task, child_task->priority, - PRIORITY_INSERT_END, - false, false); + assert (child_task->detach_team == team); + child_task->kind = GOMP_TASK_DETACHED; ++team->task_detach_count; - gomp_debug (0, "thread %d: queueing task with event %p\n", - thr->ts.team_id, &child_task->completion_sem); + --team->task_running_count; + gomp_debug (0, + "thread %d: task with event %p finished without " + "completion event fulfilled in team barrier\n", + thr->ts.team_id, child_task); child_task = NULL; + continue; } - else + + finish_cancelled:; + size_t new_tasks + = gomp_task_run_post_handle_depend (child_task, team); + gomp_task_run_post_remove_parent (child_task); + gomp_clear_parent (&child_task->children_queue); + gomp_task_run_post_remove_taskgroup (child_task); + to_free = child_task; + if (!cancelled) + team->task_running_count--; + child_task = NULL; + if (new_tasks > 1) { - finish_cancelled:; - size_t new_tasks - = gomp_task_run_post_handle_depend (child_task, team); - gomp_task_run_post_remove_parent (child_task); - gomp_clear_parent (&child_task->children_queue); - gomp_task_run_post_remove_taskgroup (child_task); - to_free = child_task; - child_task = NULL; - if (!cancelled) - team->task_running_count--; - if (new_tasks > 1) - { - do_wake = team->nthreads - team->task_running_count; - if (do_wake > new_tasks) - do_wake = new_tasks; - } - if (--team->task_count == 0 - && gomp_team_barrier_waiting_for_tasks (&team->barrier)) - { - gomp_team_barrier_done (&team->barrier, state); - gomp_mutex_unlock (&team->task_lock); - gomp_team_barrier_wake (&team->barrier, 0); - gomp_mutex_lock (&team->task_lock); - } + do_wake = team->nthreads - team->task_running_count; + if (do_wake > new_tasks) + do_wake = new_tasks; + } + if (--team->task_count == 0 + && gomp_team_barrier_waiting_for_tasks (&team->barrier)) + { + gomp_team_barrier_done (&team->barrier, state); + gomp_mutex_unlock (&team->task_lock); + gomp_team_barrier_wake (&team->barrier, 0); + gomp_mutex_lock (&team->task_lock); } } } @@ -1559,7 +1532,8 @@ GOMP_taskwait (void) else { /* All tasks we are waiting for are either running in other - threads, or they are tasks that have not had their + threads, are detached and waiting for the completion event to be + fulfilled, or they are tasks that have not had their dependencies met (so they're not even in the queue). Wait for them. */ if (task->taskwait == NULL) @@ -1614,6 +1588,19 @@ GOMP_taskwait (void) gomp_mutex_lock (&team->task_lock); if (child_task) { + if (child_task->detach_team) + { + assert (child_task->detach_team == team); + child_task->kind = GOMP_TASK_DETACHED; + ++team->task_detach_count; + gomp_debug (0, + "thread %d: task with event %p finished without " + "completion event fulfilled in taskwait\n", + thr->ts.team_id, child_task); + child_task = NULL; + continue; + } + finish_cancelled:; size_t new_tasks = gomp_task_run_post_handle_depend (child_task, team); @@ -2069,6 +2056,19 @@ GOMP_taskgroup_end (void) gomp_mutex_lock (&team->task_lock); if (child_task) { + if (child_task->detach_team) + { + assert (child_task->detach_team == team); + child_task->kind = GOMP_TASK_DETACHED; + ++team->task_detach_count; + gomp_debug (0, + "thread %d: task with event %p finished without " + "completion event fulfilled in taskgroup\n", + thr->ts.team_id, child_task); + child_task = NULL; + continue; + } + finish_cancelled:; size_t new_tasks = gomp_task_run_post_handle_depend (child_task, team); @@ -2402,17 +2402,80 @@ ialias (omp_in_final) void omp_fulfill_event (omp_event_handle_t event) { - gomp_sem_t *sem = (gomp_sem_t *) event; - struct gomp_thread *thr = gomp_thread (); - struct gomp_team *team = thr ? thr->ts.team : NULL; + struct gomp_task *task = (struct gomp_task *) event; + if (task->kind == GOMP_TASK_UNDEFERRED) + { + if (gomp_sem_getcount (&task->completion_sem) > 0) + gomp_fatal ("omp_fulfill_event: %p event already fulfilled!\n", task); + + gomp_debug (0, "omp_fulfill_event: %p event for undeferred task\n", task); + gomp_sem_post (&task->completion_sem); + return; + } - if (gomp_sem_getcount (sem) > 0) - gomp_fatal ("omp_fulfill_event: %p event already fulfilled!\n", sem); + struct gomp_team *team = task->detach_team; + if (!team) + gomp_fatal ("omp_fulfill_event: %p event is invalid or has already " + "been fulfilled!\n", task); - gomp_debug (0, "omp_fulfill_event: %p\n", sem); - gomp_sem_post (sem); - if (team) - gomp_team_barrier_wake (&team->barrier, 1); + gomp_mutex_lock (&team->task_lock); + if (task->kind != GOMP_TASK_DETACHED) + { + /* The task has not finished running yet. */ + gomp_debug (0, + "omp_fulfill_event: %p event fulfilled for unfinished " + "task\n", task); + task->detach_team = NULL; + gomp_mutex_unlock (&team->task_lock); + return; + } + + gomp_debug (0, "omp_fulfill_event: %p event fulfilled for finished task\n", + task); + size_t new_tasks = gomp_task_run_post_handle_depend (task, team); + gomp_task_run_post_remove_parent (task); + gomp_clear_parent (&task->children_queue); + gomp_task_run_post_remove_taskgroup (task); + team->task_count--; + team->task_detach_count--; + + /* Wake up any threads that may be waiting for the detached task + to complete. */ + struct gomp_task *parent = task->parent; + + if (parent && parent->taskwait) + { + if (parent->taskwait->in_taskwait) + { + parent->taskwait->in_taskwait = false; + gomp_sem_post (&parent->taskwait->taskwait_sem); + } + else if (parent->taskwait->in_depend_wait) + { + parent->taskwait->in_depend_wait = false; + gomp_sem_post (&parent->taskwait->taskwait_sem); + } + } + if (task->taskgroup && task->taskgroup->in_taskgroup_wait) + { + task->taskgroup->in_taskgroup_wait = false; + gomp_sem_post (&task->taskgroup->taskgroup_sem); + } + + int do_wake = 0; + if (new_tasks > 1) + { + do_wake = team->nthreads - team->task_running_count; + if (do_wake > new_tasks) + do_wake = new_tasks; + } + + gomp_mutex_unlock (&team->task_lock); + if (do_wake) + gomp_team_barrier_wake (&team->barrier, do_wake); + + gomp_finish_task (task); + free (task); } ialias (omp_fulfill_event) diff --git a/libgomp/team.c b/libgomp/team.c index 0f3707c..9662234 100644 --- a/libgomp/team.c +++ b/libgomp/team.c @@ -206,7 +206,6 @@ gomp_new_team (unsigned nthreads) team->work_share_cancelled = 0; team->team_cancelled = 0; - priority_queue_init (&team->task_detach_queue); team->task_detach_count = 0; return team; @@ -224,7 +223,6 @@ free_team (struct gomp_team *team) gomp_barrier_destroy (&team->barrier); gomp_mutex_destroy (&team->task_lock); priority_queue_free (&team->task_queue); - priority_queue_free (&team->task_detach_queue); team_free (team); } diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-1.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-1.c index 8583e37..14932b0 100644 --- a/libgomp/testsuite/libgomp.c-c++-common/task-detach-1.c +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-1.c @@ -14,10 +14,10 @@ int main (void) #pragma omp parallel #pragma omp single { - #pragma omp task detach(detach_event1) + #pragma omp task detach (detach_event1) x++; - #pragma omp task detach(detach_event2) + #pragma omp task detach (detach_event2) { y++; omp_fulfill_event (detach_event1); diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-10.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-10.c new file mode 100644 index 0000000..10d6746 --- /dev/null +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-10.c @@ -0,0 +1,45 @@ +/* { dg-do run } */ + +#include <omp.h> +#include <assert.h> + +/* Test tasks with detach clause on an offload device. Each device + thread spawns off a chain of tasks in a taskgroup, that can then + be executed by any available thread. */ + +int main (void) +{ + int x = 0, y = 0, z = 0; + int thread_count; + omp_event_handle_t detach_event1, detach_event2; + + #pragma omp target map (tofrom: x, y, z) map (from: thread_count) + #pragma omp parallel private (detach_event1, detach_event2) + #pragma omp taskgroup + { + #pragma omp single + thread_count = omp_get_num_threads (); + + #pragma omp task detach (detach_event1) untied + #pragma omp atomic update + x++; + + #pragma omp task detach (detach_event2) untied + { + #pragma omp atomic update + y++; + omp_fulfill_event (detach_event1); + } + + #pragma omp task untied + { + #pragma omp atomic update + z++; + omp_fulfill_event (detach_event2); + } + } + + assert (x == thread_count); + assert (y == thread_count); + assert (z == thread_count); +} diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-11.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-11.c new file mode 100644 index 0000000..dd002dc --- /dev/null +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-11.c @@ -0,0 +1,13 @@ +/* { dg-do run } */ + +#include <omp.h> + +/* Test the detach clause when the task is undeferred. */ + +int main (void) +{ + omp_event_handle_t event; + + #pragma omp task detach (event) + omp_fulfill_event (event); +} diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-2.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-2.c index 943ac2a..3e33c40 100644 --- a/libgomp/testsuite/libgomp.c-c++-common/task-detach-2.c +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-2.c @@ -12,13 +12,13 @@ int main (void) omp_event_handle_t detach_event1, detach_event2; int x = 0, y = 0, z = 0; - #pragma omp parallel num_threads(1) + #pragma omp parallel num_threads (1) #pragma omp single { - #pragma omp task detach(detach_event1) + #pragma omp task detach (detach_event1) x++; - #pragma omp task detach(detach_event2) + #pragma omp task detach (detach_event2) { y++; omp_fulfill_event (detach_event1); diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-3.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-3.c index 2609fb1..c85857d 100644 --- a/libgomp/testsuite/libgomp.c-c++-common/task-detach-3.c +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-3.c @@ -14,16 +14,16 @@ int main (void) #pragma omp parallel #pragma omp single { - #pragma omp task depend(out:dep) detach(detach_event) + #pragma omp task depend (out:dep) detach (detach_event) x++; #pragma omp task { y++; - omp_fulfill_event(detach_event); + omp_fulfill_event (detach_event); } - #pragma omp task depend(in:dep) + #pragma omp task depend (in:dep) z++; } diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-4.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-4.c index eeb9554..cd0d2b3 100644 --- a/libgomp/testsuite/libgomp.c-c++-common/task-detach-4.c +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-4.c @@ -14,10 +14,10 @@ int main (void) #pragma omp parallel #pragma omp single - #pragma omp task detach(detach_event) + #pragma omp task detach (detach_event) { x++; - omp_fulfill_event(detach_event); + omp_fulfill_event (detach_event); } assert (x == 1); diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-5.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-5.c index 5a01517..382f377 100644 --- a/libgomp/testsuite/libgomp.c-c++-common/task-detach-5.c +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-5.c @@ -12,16 +12,16 @@ int main (void) int thread_count; omp_event_handle_t detach_event1, detach_event2; - #pragma omp parallel firstprivate(detach_event1, detach_event2) + #pragma omp parallel private (detach_event1, detach_event2) { #pragma omp single - thread_count = omp_get_num_threads(); + thread_count = omp_get_num_threads (); - #pragma omp task detach(detach_event1) untied + #pragma omp task detach (detach_event1) untied #pragma omp atomic update x++; - #pragma omp task detach(detach_event2) untied + #pragma omp task detach (detach_event2) untied { #pragma omp atomic update y++; diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-6.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-6.c index b5f68cc..e5c2291 100644 --- a/libgomp/testsuite/libgomp.c-c++-common/task-detach-6.c +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-6.c @@ -13,11 +13,11 @@ int main (void) int thread_count; omp_event_handle_t detach_event1, detach_event2; - #pragma omp target map(tofrom: x, y, z) map(from: thread_count) - #pragma omp parallel firstprivate(detach_event1, detach_event2) + #pragma omp target map (tofrom: x, y, z) map (from: thread_count) + #pragma omp parallel private (detach_event1, detach_event2) { #pragma omp single - thread_count = omp_get_num_threads(); + thread_count = omp_get_num_threads (); #pragma omp task detach(detach_event1) untied #pragma omp atomic update @@ -36,8 +36,6 @@ int main (void) z++; omp_fulfill_event (detach_event2); } - - #pragma omp taskwait } assert (x == thread_count); diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-7.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-7.c new file mode 100644 index 0000000..3f025d6 --- /dev/null +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-7.c @@ -0,0 +1,45 @@ +/* { dg-do run } */ + +#include <omp.h> +#include <assert.h> + +/* Test tasks with detach clause. Each thread spawns off a chain of tasks, + that can then be executed by any available thread. Each thread uses + taskwait to wait for the child tasks to complete. */ + +int main (void) +{ + int x = 0, y = 0, z = 0; + int thread_count; + omp_event_handle_t detach_event1, detach_event2; + + #pragma omp parallel private (detach_event1, detach_event2) + { + #pragma omp single + thread_count = omp_get_num_threads (); + + #pragma omp task detach (detach_event1) untied + #pragma omp atomic update + x++; + + #pragma omp task detach (detach_event2) untied + { + #pragma omp atomic update + y++; + omp_fulfill_event (detach_event1); + } + + #pragma omp task untied + { + #pragma omp atomic update + z++; + omp_fulfill_event (detach_event2); + } + + #pragma omp taskwait + } + + assert (x == thread_count); + assert (y == thread_count); + assert (z == thread_count); +} diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-8.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-8.c new file mode 100644 index 0000000..6f77f12 --- /dev/null +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-8.c @@ -0,0 +1,47 @@ +/* { dg-do run } */ + +#include <omp.h> +#include <assert.h> + +/* Test tasks with detach clause on an offload device. Each device + thread spawns off a chain of tasks, that can then be executed by + any available thread. Each thread uses taskwait to wait for the + child tasks to complete. */ + +int main (void) +{ + int x = 0, y = 0, z = 0; + int thread_count; + omp_event_handle_t detach_event1, detach_event2; + + #pragma omp target map (tofrom: x, y, z) map (from: thread_count) + #pragma omp parallel private (detach_event1, detach_event2) + { + #pragma omp single + thread_count = omp_get_num_threads (); + + #pragma omp task detach (detach_event1) untied + #pragma omp atomic update + x++; + + #pragma omp task detach (detach_event2) untied + { + #pragma omp atomic update + y++; + omp_fulfill_event (detach_event1); + } + + #pragma omp task untied + { + #pragma omp atomic update + z++; + omp_fulfill_event (detach_event2); + } + + #pragma omp taskwait + } + + assert (x == thread_count); + assert (y == thread_count); + assert (z == thread_count); +} diff --git a/libgomp/testsuite/libgomp.c-c++-common/task-detach-9.c b/libgomp/testsuite/libgomp.c-c++-common/task-detach-9.c new file mode 100644 index 0000000..5316ca5 --- /dev/null +++ b/libgomp/testsuite/libgomp.c-c++-common/task-detach-9.c @@ -0,0 +1,43 @@ +/* { dg-do run } */ + +#include <omp.h> +#include <assert.h> + +/* Test tasks with detach clause. Each thread spawns off a chain of tasks + in a taskgroup, that can then be executed by any available thread. */ + +int main (void) +{ + int x = 0, y = 0, z = 0; + int thread_count; + omp_event_handle_t detach_event1, detach_event2; + + #pragma omp parallel private (detach_event1, detach_event2) + #pragma omp taskgroup + { + #pragma omp single + thread_count = omp_get_num_threads (); + + #pragma omp task detach (detach_event1) untied + #pragma omp atomic update + x++; + + #pragma omp task detach (detach_event2) untied + { + #pragma omp atomic update + y++; + omp_fulfill_event (detach_event1); + } + + #pragma omp task untied + { + #pragma omp atomic update + z++; + omp_fulfill_event (detach_event2); + } + } + + assert (x == thread_count); + assert (y == thread_count); + assert (z == thread_count); +} diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-1.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-1.f90 index 217bf65..c53b1ca 100644 --- a/libgomp/testsuite/libgomp.fortran/task-detach-1.f90 +++ b/libgomp/testsuite/libgomp.fortran/task-detach-1.f90 @@ -11,11 +11,11 @@ program task_detach_1 !$omp parallel !$omp single - !$omp task detach(detach_event1) + !$omp task detach (detach_event1) x = x + 1 !$omp end task - !$omp task detach(detach_event2) + !$omp task detach (detach_event2) y = y + 1 call omp_fulfill_event (detach_event1) !$omp end task diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-10.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-10.f90 new file mode 100644 index 0000000..61f0ea8 --- /dev/null +++ b/libgomp/testsuite/libgomp.fortran/task-detach-10.f90 @@ -0,0 +1,44 @@ +! { dg-do run } + +! Test tasks with detach clause on an offload device. Each device +! thread spawns off a chain of tasks in a taskgroup, that can then +! be executed by any available thread. + +program task_detach_10 + use omp_lib + + integer (kind=omp_event_handle_kind) :: detach_event1, detach_event2 + integer :: x = 0, y = 0, z = 0 + integer :: thread_count + + !$omp target map (tofrom: x, y, z) map (from: thread_count) + !$omp parallel private (detach_event1, detach_event2) + !$omp taskgroup + !$omp single + thread_count = omp_get_num_threads () + !$omp end single + + !$omp task detach (detach_event1) untied + !$omp atomic update + x = x + 1 + !$omp end task + + !$omp task detach (detach_event2) untied + !$omp atomic update + y = y + 1 + call omp_fulfill_event (detach_event1) + !$omp end task + + !$omp task untied + !$omp atomic update + z = z + 1 + call omp_fulfill_event (detach_event2) + !$omp end task + !$omp end taskgroup + !$omp end parallel + !$omp end target + + if (x /= thread_count) stop 1 + if (y /= thread_count) stop 2 + if (z /= thread_count) stop 3 +end program diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-11.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-11.f90 new file mode 100644 index 0000000..b33baff --- /dev/null +++ b/libgomp/testsuite/libgomp.fortran/task-detach-11.f90 @@ -0,0 +1,13 @@ +! { dg-do run } + +! Test the detach clause when the task is undeferred. + +program task_detach_11 + use omp_lib + + integer (kind=omp_event_handle_kind) :: detach_event + + !$omp task detach (detach_event) + call omp_fulfill_event (detach_event) + !$omp end task +end program diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-2.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-2.f90 index ecb4829..68e3ff2 100644 --- a/libgomp/testsuite/libgomp.fortran/task-detach-2.f90 +++ b/libgomp/testsuite/libgomp.fortran/task-detach-2.f90 @@ -10,13 +10,13 @@ program task_detach_2 integer (kind=omp_event_handle_kind) :: detach_event1, detach_event2 integer :: x = 0, y = 0, z = 0 - !$omp parallel num_threads(1) + !$omp parallel num_threads (1) !$omp single - !$omp task detach(detach_event1) + !$omp task detach (detach_event1) x = x + 1 !$omp end task - !$omp task detach(detach_event2) + !$omp task detach (detach_event2) y = y + 1 call omp_fulfill_event (detach_event1) !$omp end task diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-3.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-3.f90 index bdf93a5..5ac68d5 100644 --- a/libgomp/testsuite/libgomp.fortran/task-detach-3.f90 +++ b/libgomp/testsuite/libgomp.fortran/task-detach-3.f90 @@ -12,16 +12,16 @@ program task_detach_3 !$omp parallel !$omp single - !$omp task depend(out:dep) detach(detach_event) + !$omp task depend (out:dep) detach (detach_event) x = x + 1 !$omp end task !$omp task y = y + 1 - call omp_fulfill_event(detach_event) + call omp_fulfill_event (detach_event) !$omp end task - !$omp task depend(in:dep) + !$omp task depend (in:dep) z = z + 1 !$omp end task !$omp end single diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-4.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-4.f90 index 6d0843c..159624c 100644 --- a/libgomp/testsuite/libgomp.fortran/task-detach-4.f90 +++ b/libgomp/testsuite/libgomp.fortran/task-detach-4.f90 @@ -11,9 +11,9 @@ program task_detach_4 !$omp parallel !$omp single - !$omp task detach(detach_event) + !$omp task detach (detach_event) x = x + 1 - call omp_fulfill_event(detach_event) + call omp_fulfill_event (detach_event) !$omp end task !$omp end single !$omp end parallel diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-5.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-5.f90 index 955d687..95bd132 100644 --- a/libgomp/testsuite/libgomp.fortran/task-detach-5.f90 +++ b/libgomp/testsuite/libgomp.fortran/task-detach-5.f90 @@ -10,17 +10,17 @@ program task_detach_5 integer :: x = 0, y = 0, z = 0 integer :: thread_count - !$omp parallel firstprivate(detach_event1, detach_event2) + !$omp parallel private (detach_event1, detach_event2) !$omp single - thread_count = omp_get_num_threads() + thread_count = omp_get_num_threads () !$omp end single - !$omp task detach(detach_event1) untied + !$omp task detach (detach_event1) untied !$omp atomic update x = x + 1 !$omp end task - !$omp task detach(detach_event2) untied + !$omp task detach (detach_event2) untied !$omp atomic update y = y + 1 call omp_fulfill_event (detach_event1); diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-6.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-6.f90 index 0fe2155..b2c476f 100644 --- a/libgomp/testsuite/libgomp.fortran/task-detach-6.f90 +++ b/libgomp/testsuite/libgomp.fortran/task-detach-6.f90 @@ -11,30 +11,28 @@ program task_detach_6 integer :: x = 0, y = 0, z = 0 integer :: thread_count - !$omp target map(tofrom: x, y, z) map(from: thread_count) - !$omp parallel firstprivate(detach_event1, detach_event2) + !$omp target map (tofrom: x, y, z) map (from: thread_count) + !$omp parallel private (detach_event1, detach_event2) !$omp single - thread_count = omp_get_num_threads() + thread_count = omp_get_num_threads () !$omp end single - !$omp task detach(detach_event1) untied + !$omp task detach (detach_event1) untied !$omp atomic update x = x + 1 !$omp end task - !$omp task detach(detach_event2) untied + !$omp task detach (detach_event2) untied !$omp atomic update y = y + 1 - call omp_fulfill_event (detach_event1); + call omp_fulfill_event (detach_event1) !$omp end task !$omp task untied !$omp atomic update z = z + 1 - call omp_fulfill_event (detach_event2); + call omp_fulfill_event (detach_event2) !$omp end task - - !$omp taskwait !$omp end parallel !$omp end target diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-7.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-7.f90 new file mode 100644 index 0000000..32e715e --- /dev/null +++ b/libgomp/testsuite/libgomp.fortran/task-detach-7.f90 @@ -0,0 +1,42 @@ +! { dg-do run } + +! Test tasks with detach clause. Each thread spawns off a chain of tasks, +! that can then be executed by any available thread. Each thread uses +! taskwait to wait for the child tasks to complete. + +program task_detach_7 + use omp_lib + + integer (kind=omp_event_handle_kind) :: detach_event1, detach_event2 + integer :: x = 0, y = 0, z = 0 + integer :: thread_count + + !$omp parallel private (detach_event1, detach_event2) + !$omp single + thread_count = omp_get_num_threads() + !$omp end single + + !$omp task detach (detach_event1) untied + !$omp atomic update + x = x + 1 + !$omp end task + + !$omp task detach (detach_event2) untied + !$omp atomic update + y = y + 1 + call omp_fulfill_event (detach_event1) + !$omp end task + + !$omp task untied + !$omp atomic update + z = z + 1 + call omp_fulfill_event (detach_event2) + !$omp end task + + !$omp taskwait + !$omp end parallel + + if (x /= thread_count) stop 1 + if (y /= thread_count) stop 2 + if (z /= thread_count) stop 3 +end program diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-8.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-8.f90 new file mode 100644 index 0000000..e760eab --- /dev/null +++ b/libgomp/testsuite/libgomp.fortran/task-detach-8.f90 @@ -0,0 +1,45 @@ +! { dg-do run } + +! Test tasks with detach clause on an offload device. Each device +! thread spawns off a chain of tasks, that can then be executed by +! any available thread. Each thread uses taskwait to wait for the +! child tasks to complete. + +program task_detach_8 + use omp_lib + + integer (kind=omp_event_handle_kind) :: detach_event1, detach_event2 + integer :: x = 0, y = 0, z = 0 + integer :: thread_count + + !$omp target map (tofrom: x, y, z) map (from: thread_count) + !$omp parallel private (detach_event1, detach_event2) + !$omp single + thread_count = omp_get_num_threads () + !$omp end single + + !$omp task detach (detach_event1) untied + !$omp atomic update + x = x + 1 + !$omp end task + + !$omp task detach (detach_event2) untied + !$omp atomic update + y = y + 1 + call omp_fulfill_event (detach_event1) + !$omp end task + + !$omp task untied + !$omp atomic update + z = z + 1 + call omp_fulfill_event (detach_event2) + !$omp end task + + !$omp taskwait + !$omp end parallel + !$omp end target + + if (x /= thread_count) stop 1 + if (y /= thread_count) stop 2 + if (z /= thread_count) stop 3 +end program diff --git a/libgomp/testsuite/libgomp.fortran/task-detach-9.f90 b/libgomp/testsuite/libgomp.fortran/task-detach-9.f90 new file mode 100644 index 0000000..540c6de --- /dev/null +++ b/libgomp/testsuite/libgomp.fortran/task-detach-9.f90 @@ -0,0 +1,41 @@ +! { dg-do run } + +! Test tasks with detach clause. Each thread spawns off a chain of tasks +! in a taskgroup, that can then be executed by any available thread. + +program task_detach_9 + use omp_lib + + integer (kind=omp_event_handle_kind) :: detach_event1, detach_event2 + integer :: x = 0, y = 0, z = 0 + integer :: thread_count + + !$omp parallel private (detach_event1, detach_event2) + !$omp taskgroup + !$omp single + thread_count = omp_get_num_threads () + !$omp end single + + !$omp task detach (detach_event1) untied + !$omp atomic update + x = x + 1 + !$omp end task + + !$omp task detach (detach_event2) untied + !$omp atomic update + y = y + 1 + call omp_fulfill_event (detach_event1); + !$omp end task + + !$omp task untied + !$omp atomic update + z = z + 1 + call omp_fulfill_event (detach_event2); + !$omp end task + !$omp end taskgroup + !$omp end parallel + + if (x /= thread_count) stop 1 + if (y /= thread_count) stop 2 + if (z /= thread_count) stop 3 +end program