From 0fdb73112b6fb40af46a99e3251c340935a121ad Mon Sep 17 00:00:00 2001 From: Emanuele Giuseppe Esposito Date: Fri, 3 Feb 2023 08:17:30 -0500 Subject: thread-pool: use ThreadPool from the running thread Use qemu_get_current_aio_context() where possible, since we always submit work to the current thread anyways. We want to also be sure that the thread submitting the work is the same as the one processing the pool, to avoid adding synchronization to the pool list. Signed-off-by: Emanuele Giuseppe Esposito Message-Id: <20230203131731.851116-4-eesposit@redhat.com> Reviewed-by: Kevin Wolf Reviewed-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- util/thread-pool.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) (limited to 'util') diff --git a/util/thread-pool.c b/util/thread-pool.c index 31113b5..a70abb8 100644 --- a/util/thread-pool.c +++ b/util/thread-pool.c @@ -48,7 +48,7 @@ struct ThreadPoolElement { /* Access to this list is protected by lock. */ QTAILQ_ENTRY(ThreadPoolElement) reqs; - /* Access to this list is protected by the global mutex. */ + /* This list is only written by the thread pool's mother thread. */ QLIST_ENTRY(ThreadPoolElement) all; }; @@ -175,7 +175,6 @@ static void thread_pool_completion_bh(void *opaque) ThreadPool *pool = opaque; ThreadPoolElement *elem, *next; - aio_context_acquire(pool->ctx); restart: QLIST_FOREACH_SAFE(elem, &pool->head, all, next) { if (elem->state != THREAD_DONE) { @@ -195,9 +194,7 @@ restart: */ qemu_bh_schedule(pool->completion_bh); - aio_context_release(pool->ctx); elem->common.cb(elem->common.opaque, elem->ret); - aio_context_acquire(pool->ctx); /* We can safely cancel the completion_bh here regardless of someone * else having scheduled it meanwhile because we reenter the @@ -211,7 +208,6 @@ restart: qemu_aio_unref(elem); } } - aio_context_release(pool->ctx); } static void thread_pool_cancel(BlockAIOCB *acb) @@ -251,6 +247,9 @@ BlockAIOCB *thread_pool_submit_aio(ThreadPool *pool, { ThreadPoolElement *req; + /* Assert that the thread submitting work is the same running the pool */ + assert(pool->ctx == qemu_get_current_aio_context()); + req = qemu_aio_get(&thread_pool_aiocb_info, NULL, cb, opaque); req->func = func; req->arg = arg; -- cgit v1.1 From aef04fc79084fe340c931679413eb6070f2f13ca Mon Sep 17 00:00:00 2001 From: Emanuele Giuseppe Esposito Date: Fri, 3 Feb 2023 08:17:31 -0500 Subject: thread-pool: avoid passing the pool parameter every time thread_pool_submit_aio() is always called on a pool taken from qemu_get_current_aio_context(), and that is the only intended use: each pool runs only in the same thread that is submitting work to it, it can't run anywhere else. Therefore simplify the thread_pool_submit* API and remove the ThreadPool function parameter. Signed-off-by: Emanuele Giuseppe Esposito Message-Id: <20230203131731.851116-5-eesposit@redhat.com> Reviewed-by: Kevin Wolf Reviewed-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- util/thread-pool.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) (limited to 'util') diff --git a/util/thread-pool.c b/util/thread-pool.c index a70abb8..0d97888 100644 --- a/util/thread-pool.c +++ b/util/thread-pool.c @@ -241,11 +241,12 @@ static const AIOCBInfo thread_pool_aiocb_info = { .get_aio_context = thread_pool_get_aio_context, }; -BlockAIOCB *thread_pool_submit_aio(ThreadPool *pool, - ThreadPoolFunc *func, void *arg, - BlockCompletionFunc *cb, void *opaque) +BlockAIOCB *thread_pool_submit_aio(ThreadPoolFunc *func, void *arg, + BlockCompletionFunc *cb, void *opaque) { ThreadPoolElement *req; + AioContext *ctx = qemu_get_current_aio_context(); + ThreadPool *pool = aio_get_thread_pool(ctx); /* Assert that the thread submitting work is the same running the pool */ assert(pool->ctx == qemu_get_current_aio_context()); @@ -283,19 +284,18 @@ static void thread_pool_co_cb(void *opaque, int ret) aio_co_wake(co->co); } -int coroutine_fn thread_pool_submit_co(ThreadPool *pool, ThreadPoolFunc *func, - void *arg) +int coroutine_fn thread_pool_submit_co(ThreadPoolFunc *func, void *arg) { ThreadPoolCo tpc = { .co = qemu_coroutine_self(), .ret = -EINPROGRESS }; assert(qemu_in_coroutine()); - thread_pool_submit_aio(pool, func, arg, thread_pool_co_cb, &tpc); + thread_pool_submit_aio(func, arg, thread_pool_co_cb, &tpc); qemu_coroutine_yield(); return tpc.ret; } -void thread_pool_submit(ThreadPool *pool, ThreadPoolFunc *func, void *arg) +void thread_pool_submit(ThreadPoolFunc *func, void *arg) { - thread_pool_submit_aio(pool, func, arg, NULL, NULL); + thread_pool_submit_aio(func, arg, NULL, NULL); } void thread_pool_update_params(ThreadPool *pool, AioContext *ctx) -- cgit v1.1