Message ID | 20220725073855.76049-5-eesposit@redhat.com |
---|---|
State | New |
Headers | show |
Series | job: replace AioContext lock with job_mutex | expand |
Am 25.07.2022 um 09:38 hat Emanuele Giuseppe Esposito geschrieben: > Same as AIO_WAIT_WHILE macro, but if we are in the Main loop > do not release and then acquire ctx_ 's aiocontext. > > Once all Aiocontext locks go away, this macro will replace > AIO_WAIT_WHILE. > > Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> > Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> > Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> > --- > include/block/aio-wait.h | 17 +++++++++++++---- > 1 file changed, 13 insertions(+), 4 deletions(-) > > diff --git a/include/block/aio-wait.h b/include/block/aio-wait.h > index 54840f8622..a61f82c617 100644 > --- a/include/block/aio-wait.h > +++ b/include/block/aio-wait.h > @@ -59,10 +59,13 @@ typedef struct { > extern AioWait global_aio_wait; > > /** > - * AIO_WAIT_WHILE: > + * _AIO_WAIT_WHILE: > * @ctx: the aio context, or NULL if multiple aio contexts (for which the > * caller does not hold a lock) are involved in the polling condition. > * @cond: wait while this conditional expression is true > + * @unlock: whether to unlock and then lock again @ctx. This apples > + * only when waiting for another AioContext from the main loop. > + * Otherwise it's ignored. > * > * Wait while a condition is true. Use this to implement synchronous > * operations that require event loop activity. > @@ -75,7 +78,7 @@ extern AioWait global_aio_wait; > * wait on conditions between two IOThreads since that could lead to deadlock, > * go via the main loop instead. > */ > -#define AIO_WAIT_WHILE(ctx, cond) ({ \ > +#define _AIO_WAIT_WHILE(ctx, cond, unlock) ({ \ "All identifiers that begin with an underscore and either an uppercase letter or another underscore are always reserved for any use." (C11, 7.1.3) Kevin
diff --git a/include/block/aio-wait.h b/include/block/aio-wait.h index 54840f8622..a61f82c617 100644 --- a/include/block/aio-wait.h +++ b/include/block/aio-wait.h @@ -59,10 +59,13 @@ typedef struct { extern AioWait global_aio_wait; /** - * AIO_WAIT_WHILE: + * _AIO_WAIT_WHILE: * @ctx: the aio context, or NULL if multiple aio contexts (for which the * caller does not hold a lock) are involved in the polling condition. * @cond: wait while this conditional expression is true + * @unlock: whether to unlock and then lock again @ctx. This apples + * only when waiting for another AioContext from the main loop. + * Otherwise it's ignored. * * Wait while a condition is true. Use this to implement synchronous * operations that require event loop activity. @@ -75,7 +78,7 @@ extern AioWait global_aio_wait; * wait on conditions between two IOThreads since that could lead to deadlock, * go via the main loop instead. */ -#define AIO_WAIT_WHILE(ctx, cond) ({ \ +#define _AIO_WAIT_WHILE(ctx, cond, unlock) ({ \ bool waited_ = false; \ AioWait *wait_ = &global_aio_wait; \ AioContext *ctx_ = (ctx); \ @@ -92,11 +95,11 @@ extern AioWait global_aio_wait; assert(qemu_get_current_aio_context() == \ qemu_get_aio_context()); \ while ((cond)) { \ - if (ctx_) { \ + if (unlock && ctx_) { \ aio_context_release(ctx_); \ } \ aio_poll(qemu_get_aio_context(), true); \ - if (ctx_) { \ + if (unlock && ctx_) { \ aio_context_acquire(ctx_); \ } \ waited_ = true; \ @@ -105,6 +108,12 @@ extern AioWait global_aio_wait; qatomic_dec(&wait_->num_waiters); \ waited_; }) +#define AIO_WAIT_WHILE(ctx, cond) \ + _AIO_WAIT_WHILE(ctx, cond, true) + +#define AIO_WAIT_WHILE_UNLOCKED(ctx, cond) \ + _AIO_WAIT_WHILE(ctx, cond, false) + /** * aio_wait_kick: * Wake up the main thread if it is waiting on AIO_WAIT_WHILE(). During