| Message ID | 20190814020218.1868-4-quintela@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | Fix multifd with big number of channels | expand |
* Juan Quintela (quintela@redhat.com) wrote: > If we start the migration before all have been created, we have to > handle the case that one channel still don't exist. This way it is > easier. > > Signed-off-by: Juan Quintela <quintela@redhat.com> > --- > migration/ram.c | 14 ++++++++++++++ > migration/trace-events | 1 + > 2 files changed, 15 insertions(+) > > diff --git a/migration/ram.c b/migration/ram.c > index 4bdd201a4e..4a6ae677a9 100644 > --- a/migration/ram.c > +++ b/migration/ram.c > @@ -663,6 +663,8 @@ typedef struct { > uint64_t num_pages; > /* syncs main thread and channels */ > QemuSemaphore sem_sync; > + /* thread has started and setup is done */ > + QemuSemaphore started; > } MultiFDSendParams; > > typedef struct { > @@ -1039,6 +1041,7 @@ void multifd_save_cleanup(void) > qemu_mutex_destroy(&p->mutex); > qemu_sem_destroy(&p->sem); > qemu_sem_destroy(&p->sem_sync); > + qemu_sem_destroy(&p->started); > g_free(p->name); > p->name = NULL; > multifd_pages_clear(p->pages); > @@ -1113,6 +1116,8 @@ static void *multifd_send_thread(void *opaque) > /* initial packet */ > p->num_packets = 1; > > + qemu_sem_post(&p->started); > + > while (true) { > qemu_sem_wait(&p->sem); > qemu_mutex_lock(&p->mutex); > @@ -1229,6 +1234,7 @@ int multifd_save_setup(void) > qemu_mutex_init(&p->mutex); > qemu_sem_init(&p->sem, 0); > qemu_sem_init(&p->sem_sync, 0); > + qemu_sem_init(&p->started, 0); > p->quit = false; > p->pending_job = 0; > p->id = i; > @@ -3486,6 +3492,14 @@ static int ram_save_setup(QEMUFile *f, void *opaque) > ram_control_before_iterate(f, RAM_CONTROL_SETUP); > ram_control_after_iterate(f, RAM_CONTROL_SETUP); > > + /* We want to wait for all threads to have started before doing > + * anything else */ > + for (int i = 0; i < migrate_multifd_channels(); i++) { > + MultiFDSendParams *p = &multifd_send_state->params[i]; > + > + qemu_sem_wait(&p->started); > + trace_multifd_send_thread_started(p->id); > + } What happens if there's an error during startup and either we cancel or the migration fails and we try and cleanup - how do we get out of this loop? Dave > multifd_send_sync_main(); > qemu_put_be64(f, RAM_SAVE_FLAG_EOS); > qemu_fflush(f); > diff --git a/migration/trace-events b/migration/trace-events > index 886ce70ca0..dd13a5c4b1 100644 > --- a/migration/trace-events > +++ b/migration/trace-events > @@ -95,6 +95,7 @@ multifd_send_sync_main_wait(uint8_t id) "channel %d" > multifd_send_terminate_threads(bool error) "error %d" > multifd_send_thread_end(uint8_t id, uint64_t packets, uint64_t pages) "channel %d packets %" PRIu64 " pages %" PRIu64 > multifd_send_thread_start(uint8_t id) "%d" > +multifd_send_thread_started(uint8_t id) "channel %d" > ram_discard_range(const char *rbname, uint64_t start, size_t len) "%s: start: %" PRIx64 " %zx" > ram_load_loop(const char *rbname, uint64_t addr, int flags, void *host) "%s: addr: 0x%" PRIx64 " flags: 0x%x host: %p" > ram_load_postcopy_loop(uint64_t addr, int flags) "@%" PRIx64 " %x" > -- > 2.21.0 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
"Dr. David Alan Gilbert" <dgilbert@redhat.com> wrote: > * Juan Quintela (quintela@redhat.com) wrote: >> If we start the migration before all have been created, we have to >> handle the case that one channel still don't exist. This way it is >> easier. >> >> Signed-off-by: Juan Quintela <quintela@redhat.com> >> @@ -3486,6 +3492,14 @@ static int ram_save_setup(QEMUFile *f, void *opaque) >> ram_control_before_iterate(f, RAM_CONTROL_SETUP); >> ram_control_after_iterate(f, RAM_CONTROL_SETUP); >> >> + /* We want to wait for all threads to have started before doing >> + * anything else */ >> + for (int i = 0; i < migrate_multifd_channels(); i++) { >> + MultiFDSendParams *p = &multifd_send_state->params[i]; >> + >> + qemu_sem_wait(&p->started); >> + trace_multifd_send_thread_started(p->id); >> + } > > What happens if there's an error during startup and either we cancel or > the migration fails and we try and cleanup - how do we get out of this > loop? Good catch. Will think a way to do it. Thanks. > Dave > >> multifd_send_sync_main(); >> qemu_put_be64(f, RAM_SAVE_FLAG_EOS); >> qemu_fflush(f); >> diff --git a/migration/trace-events b/migration/trace-events >> index 886ce70ca0..dd13a5c4b1 100644 >> --- a/migration/trace-events >> +++ b/migration/trace-events >> @@ -95,6 +95,7 @@ multifd_send_sync_main_wait(uint8_t id) "channel %d" >> multifd_send_terminate_threads(bool error) "error %d" >> multifd_send_thread_end(uint8_t id, uint64_t packets, uint64_t pages) "channel %d packets %" PRIu64 " pages %" PRIu64 >> multifd_send_thread_start(uint8_t id) "%d" >> +multifd_send_thread_started(uint8_t id) "channel %d" >> ram_discard_range(const char *rbname, uint64_t start, size_t len) "%s: start: %" PRIx64 " %zx" >> ram_load_loop(const char *rbname, uint64_t addr, int flags, void *host) "%s: addr: 0x%" PRIx64 " flags: 0x%x host: %p" >> ram_load_postcopy_loop(uint64_t addr, int flags) "@%" PRIx64 " %x" >> -- >> 2.21.0 >> > -- > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
diff --git a/migration/ram.c b/migration/ram.c index 4bdd201a4e..4a6ae677a9 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -663,6 +663,8 @@ typedef struct { uint64_t num_pages; /* syncs main thread and channels */ QemuSemaphore sem_sync; + /* thread has started and setup is done */ + QemuSemaphore started; } MultiFDSendParams; typedef struct { @@ -1039,6 +1041,7 @@ void multifd_save_cleanup(void) qemu_mutex_destroy(&p->mutex); qemu_sem_destroy(&p->sem); qemu_sem_destroy(&p->sem_sync); + qemu_sem_destroy(&p->started); g_free(p->name); p->name = NULL; multifd_pages_clear(p->pages); @@ -1113,6 +1116,8 @@ static void *multifd_send_thread(void *opaque) /* initial packet */ p->num_packets = 1; + qemu_sem_post(&p->started); + while (true) { qemu_sem_wait(&p->sem); qemu_mutex_lock(&p->mutex); @@ -1229,6 +1234,7 @@ int multifd_save_setup(void) qemu_mutex_init(&p->mutex); qemu_sem_init(&p->sem, 0); qemu_sem_init(&p->sem_sync, 0); + qemu_sem_init(&p->started, 0); p->quit = false; p->pending_job = 0; p->id = i; @@ -3486,6 +3492,14 @@ static int ram_save_setup(QEMUFile *f, void *opaque) ram_control_before_iterate(f, RAM_CONTROL_SETUP); ram_control_after_iterate(f, RAM_CONTROL_SETUP); + /* We want to wait for all threads to have started before doing + * anything else */ + for (int i = 0; i < migrate_multifd_channels(); i++) { + MultiFDSendParams *p = &multifd_send_state->params[i]; + + qemu_sem_wait(&p->started); + trace_multifd_send_thread_started(p->id); + } multifd_send_sync_main(); qemu_put_be64(f, RAM_SAVE_FLAG_EOS); qemu_fflush(f); diff --git a/migration/trace-events b/migration/trace-events index 886ce70ca0..dd13a5c4b1 100644 --- a/migration/trace-events +++ b/migration/trace-events @@ -95,6 +95,7 @@ multifd_send_sync_main_wait(uint8_t id) "channel %d" multifd_send_terminate_threads(bool error) "error %d" multifd_send_thread_end(uint8_t id, uint64_t packets, uint64_t pages) "channel %d packets %" PRIu64 " pages %" PRIu64 multifd_send_thread_start(uint8_t id) "%d" +multifd_send_thread_started(uint8_t id) "channel %d" ram_discard_range(const char *rbname, uint64_t start, size_t len) "%s: start: %" PRIx64 " %zx" ram_load_loop(const char *rbname, uint64_t addr, int flags, void *host) "%s: addr: 0x%" PRIx64 " flags: 0x%x host: %p" ram_load_postcopy_loop(uint64_t addr, int flags) "@%" PRIx64 " %x"
If we start the migration before all have been created, we have to handle the case that one channel still don't exist. This way it is easier. Signed-off-by: Juan Quintela <quintela@redhat.com> --- migration/ram.c | 14 ++++++++++++++ migration/trace-events | 1 + 2 files changed, 15 insertions(+)