util/qemu-thread-posix.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
In this case there is no need to call pthread_cond_timedwait; the
function is just a trywait and waiting on the condition variable would
always time out.
Based-on: <20220222090507.2028-1-longpeng2@huawei.com>
Cc: "Longpeng(Mike)" <longpeng2@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
util/qemu-thread-posix.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/util/qemu-thread-posix.c b/util/qemu-thread-posix.c
index f2ce47d36b..89c23f1d64 100644
--- a/util/qemu-thread-posix.c
+++ b/util/qemu-thread-posix.c
@@ -282,8 +282,12 @@ int qemu_sem_timedwait(QemuSemaphore *sem, int ms)
compute_abs_deadline(&ts, ms);
qemu_mutex_lock(&sem->mutex);
while (sem->count == 0) {
- rc = qemu_cond_timedwait_ts(&sem->cond, &sem->mutex, &ts,
- __FILE__, __LINE__);
+ if (ms == 0) {
+ rc = false;
+ } else {
+ rc = qemu_cond_timedwait_ts(&sem->cond, &sem->mutex, &ts,
+ __FILE__, __LINE__);
+ }
if (!rc) { /* timeout */
break;
}
--
2.34.1
> -----Original Message----- > From: Paolo Bonzini [mailto:paolo.bonzini@gmail.com] On Behalf Of Paolo Bonzini > Sent: Wednesday, February 23, 2022 4:36 PM > To: qemu-devel@nongnu.org > Cc: Longpeng (Mike, Cloud Infrastructure Service Product Dept.) > <longpeng2@huawei.com> > Subject: [PATCH] thread-posix: optimize qemu_sem_timedwait with zero timeout > > In this case there is no need to call pthread_cond_timedwait; the > function is just a trywait and waiting on the condition variable would > always time out. > > Based-on: <20220222090507.2028-1-longpeng2@huawei.com> > Cc: "Longpeng(Mike)" <longpeng2@huawei.com> > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > --- > util/qemu-thread-posix.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/util/qemu-thread-posix.c b/util/qemu-thread-posix.c > index f2ce47d36b..89c23f1d64 100644 > --- a/util/qemu-thread-posix.c > +++ b/util/qemu-thread-posix.c > @@ -282,8 +282,12 @@ int qemu_sem_timedwait(QemuSemaphore *sem, int ms) > compute_abs_deadline(&ts, ms); > qemu_mutex_lock(&sem->mutex); > while (sem->count == 0) { > - rc = qemu_cond_timedwait_ts(&sem->cond, &sem->mutex, &ts, > - __FILE__, __LINE__); > + if (ms == 0) { > + rc = false; > + } else { > + rc = qemu_cond_timedwait_ts(&sem->cond, &sem->mutex, &ts, > + __FILE__, __LINE__); > + } > if (!rc) { /* timeout */ > break; > } > -- > 2.34.1 Reviewed-by: Longpeng <longpeng2@huawei.com> Thanks.
On 23/2/22 09:36, Paolo Bonzini wrote: > In this case there is no need to call pthread_cond_timedwait; the > function is just a trywait and waiting on the condition variable would > always time out. > > Based-on: <20220222090507.2028-1-longpeng2@huawei.com> ^ Please remove when applying. Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> > Cc: "Longpeng(Mike)" <longpeng2@huawei.com> > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > --- > util/qemu-thread-posix.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-)
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