| Message ID | 1459870344-16773-8-git-send-email-alex.bennee@linaro.org |
|---|---|
| State | New |
| Headers | show |
On 05/04/16 18:32, Alex Bennée wrote: > diff --git a/cpus.c b/cpus.c > index e118fdf..46732a5 100644 > --- a/cpus.c > +++ b/cpus.c (snip) > @@ -1109,7 +1108,7 @@ static void *qemu_dummy_cpu_thread_fn(void *arg) > #endif > } > > -static void tcg_exec_all(void); > +static int tcg_cpu_exec(CPUState *cpu); Why don't just move tcg_cpu_exec() here and avoid this forward declaration. Such forward declarations of static functions are a bit annoying :) > > static void *qemu_tcg_cpu_thread_fn(void *arg) > { > @@ -1140,8 +1139,35 @@ static void *qemu_tcg_cpu_thread_fn(void *arg) > /* process any pending work */ > atomic_mb_set(&exit_request, 1); > > + cpu = first_cpu; > + > while (1) { > - tcg_exec_all(); > + /* Account partial waits to QEMU_CLOCK_VIRTUAL. */ > + qemu_account_warp_timer(); > + > + if (!cpu) { > + cpu = first_cpu; > + } > + > + for (; cpu != NULL && !exit_request; cpu = CPU_NEXT(cpu)) { Maybe a "while" cycle would be a bit neater here, like: while (cpu != NULL && !exit_request) { /* ... */ cpu = CPU_NEXT(cpu); } > + > + qemu_clock_enable(QEMU_CLOCK_VIRTUAL, > + (cpu->singlestep_enabled & SSTEP_NOTIMER) == 0); > + > + if (cpu_can_run(cpu)) { > + int r = tcg_cpu_exec(cpu); > + if (r == EXCP_DEBUG) { > + cpu_handle_guest_debug(cpu); > + break; > + } > + } else if (cpu->stop || cpu->stopped) { > + break; > + } > + > + } /* for cpu.. */ > + > + /* Pairs with smp_wmb in qemu_cpu_kick. */ While at it, we could also fix this comment like this: /* Pairs with atomic_mb_read() in cpu_exec(). */ > + atomic_mb_set(&exit_request, 0); > > if (use_icount) { > int64_t deadline = qemu_clock_deadline_ns_all(QEMU_CLOCK_VIRTUAL); Kind regards, Sergey
Sergey Fedorov <serge.fdrv@gmail.com> writes: > On 05/04/16 18:32, Alex Bennée wrote: >> diff --git a/cpus.c b/cpus.c >> index e118fdf..46732a5 100644 >> --- a/cpus.c >> +++ b/cpus.c > (snip) >> @@ -1109,7 +1108,7 @@ static void *qemu_dummy_cpu_thread_fn(void *arg) >> #endif >> } >> >> -static void tcg_exec_all(void); >> +static int tcg_cpu_exec(CPUState *cpu); > > Why don't just move tcg_cpu_exec() here and avoid this forward > declaration. Such forward declarations of static functions are a bit > annoying :) Sounds like a plan. > >> >> static void *qemu_tcg_cpu_thread_fn(void *arg) >> { >> @@ -1140,8 +1139,35 @@ static void *qemu_tcg_cpu_thread_fn(void *arg) >> /* process any pending work */ >> atomic_mb_set(&exit_request, 1); >> >> + cpu = first_cpu; >> + >> while (1) { >> - tcg_exec_all(); >> + /* Account partial waits to QEMU_CLOCK_VIRTUAL. */ >> + qemu_account_warp_timer(); >> + >> + if (!cpu) { >> + cpu = first_cpu; >> + } >> + >> + for (; cpu != NULL && !exit_request; cpu = CPU_NEXT(cpu)) { > > Maybe a "while" cycle would be a bit neater here, like: > > while (cpu != NULL && !exit_request) { > /* ... */ > cpu = CPU_NEXT(cpu); > } Yeah, I prefer the while to non-standard for loops. > > >> + >> + qemu_clock_enable(QEMU_CLOCK_VIRTUAL, >> + (cpu->singlestep_enabled & SSTEP_NOTIMER) == 0); >> + >> + if (cpu_can_run(cpu)) { >> + int r = tcg_cpu_exec(cpu); >> + if (r == EXCP_DEBUG) { >> + cpu_handle_guest_debug(cpu); >> + break; >> + } >> + } else if (cpu->stop || cpu->stopped) { >> + break; >> + } >> + >> + } /* for cpu.. */ >> + >> + /* Pairs with smp_wmb in qemu_cpu_kick. */ > > While at it, we could also fix this comment like this: > > /* Pairs with atomic_mb_read() in cpu_exec(). */ Will do. > >> + atomic_mb_set(&exit_request, 0); >> >> if (use_icount) { >> int64_t deadline = qemu_clock_deadline_ns_all(QEMU_CLOCK_VIRTUAL); > > Kind regards, > Sergey Thanks, -- Alex Bennée
diff --git a/cpus.c b/cpus.c index e118fdf..46732a5 100644 --- a/cpus.c +++ b/cpus.c @@ -67,7 +67,6 @@ #endif /* CONFIG_LINUX */ -static CPUState *next_cpu; int64_t max_delay; int64_t max_advance; @@ -1109,7 +1108,7 @@ static void *qemu_dummy_cpu_thread_fn(void *arg) #endif } -static void tcg_exec_all(void); +static int tcg_cpu_exec(CPUState *cpu); static void *qemu_tcg_cpu_thread_fn(void *arg) { @@ -1140,8 +1139,35 @@ static void *qemu_tcg_cpu_thread_fn(void *arg) /* process any pending work */ atomic_mb_set(&exit_request, 1); + cpu = first_cpu; + while (1) { - tcg_exec_all(); + /* Account partial waits to QEMU_CLOCK_VIRTUAL. */ + qemu_account_warp_timer(); + + if (!cpu) { + cpu = first_cpu; + } + + for (; cpu != NULL && !exit_request; cpu = CPU_NEXT(cpu)) { + + qemu_clock_enable(QEMU_CLOCK_VIRTUAL, + (cpu->singlestep_enabled & SSTEP_NOTIMER) == 0); + + if (cpu_can_run(cpu)) { + int r = tcg_cpu_exec(cpu); + if (r == EXCP_DEBUG) { + cpu_handle_guest_debug(cpu); + break; + } + } else if (cpu->stop || cpu->stopped) { + break; + } + + } /* for cpu.. */ + + /* Pairs with smp_wmb in qemu_cpu_kick. */ + atomic_mb_set(&exit_request, 0); if (use_icount) { int64_t deadline = qemu_clock_deadline_ns_all(QEMU_CLOCK_VIRTUAL); @@ -1500,37 +1526,6 @@ static int tcg_cpu_exec(CPUState *cpu) return ret; } -static void tcg_exec_all(void) -{ - int r; - - /* Account partial waits to QEMU_CLOCK_VIRTUAL. */ - qemu_account_warp_timer(); - - if (next_cpu == NULL) { - next_cpu = first_cpu; - } - for (; next_cpu != NULL && !exit_request; next_cpu = CPU_NEXT(next_cpu)) { - CPUState *cpu = next_cpu; - - qemu_clock_enable(QEMU_CLOCK_VIRTUAL, - (cpu->singlestep_enabled & SSTEP_NOTIMER) == 0); - - if (cpu_can_run(cpu)) { - r = tcg_cpu_exec(cpu); - if (r == EXCP_DEBUG) { - cpu_handle_guest_debug(cpu); - break; - } - } else if (cpu->stop || cpu->stopped) { - break; - } - } - - /* Pairs with smp_wmb in qemu_cpu_kick. */ - atomic_mb_set(&exit_request, 0); -} - void list_cpus(FILE *f, fprintf_function cpu_fprintf, const char *optarg) { /* XXX: implement xxx_cpu_list for targets that still miss it */
In preparation for multi-threaded TCG we remove tcg_exec_all and move all the CPU cycling into the main thread function. When MTTCG is enabled we shall use a separate thread function which only handles one vCPU. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> --- v2 - update timer calls to new API on rebase --- cpus.c | 63 +++++++++++++++++++++++++++++---------------------------------- 1 file changed, 29 insertions(+), 34 deletions(-)