From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42239) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d8pIT-0001cQ-KN for qemu-devel@nongnu.org; Thu, 11 May 2017 10:42:30 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d8pIS-0004Ei-K8 for qemu-devel@nongnu.org; Thu, 11 May 2017 10:42:29 -0400 From: Paolo Bonzini Date: Thu, 11 May 2017 16:41:58 +0200 Message-Id: <20170511144208.24075-9-pbonzini@redhat.com> In-Reply-To: <20170511144208.24075-1-pbonzini@redhat.com> References: <20170511144208.24075-1-pbonzini@redhat.com> Subject: [Qemu-devel] [PATCH 08/18] throttle-groups: do not use qemu_co_enter_next List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: famz@redhat.com, stefanha@redhat.com, qemu-block@nongnu.org Prepare for removing this function; always restart throttled requests from coroutine context. This will matter when restarting throttled requests will have to acquire a CoMutex. Signed-off-by: Paolo Bonzini --- v1->v2: heavily simplified thanks to previous patch [Stefan] add coroutine_fn as needed [Stefan] block/throttle-groups.c | 42 +++++++++++++++++++++++++++++++++++++----- 1 file changed, 37 insertions(+), 5 deletions(-) diff --git a/block/throttle-groups.c b/block/throttle-groups.c index 85169ecfb0..8bf1031efa 100644 --- a/block/throttle-groups.c +++ b/block/throttle-groups.c @@ -260,6 +260,20 @@ static bool throttle_group_schedule_timer(BlockBackend *blk, bool is_write) return must_wait; } +/* Start the next pending I/O request for a BlockBackend. Return whether + * any request was actually pending. + * + * @blk: the current BlockBackend + * @is_write: the type of operation (read/write) + */ +static bool coroutine_fn throttle_group_co_restart_queue(BlockBackend *blk, + bool is_write) +{ + BlockBackendPublic *blkp = blk_get_public(blk); + + return qemu_co_queue_next(&blkp->throttled_reqs[is_write]); +} + /* Look for the next pending I/O request and schedule it. * * This assumes that tg->lock is held. @@ -287,7 +301,7 @@ static void schedule_next_request(BlockBackend *blk, bool is_write) if (!must_wait) { /* Give preference to requests from the current blk */ if (qemu_in_coroutine() && - qemu_co_queue_next(&blkp->throttled_reqs[is_write])) { + throttle_group_co_restart_queue(blk, is_write)) { token = blk; } else { ThrottleTimers *tt = &blk_get_public(token)->throttle_timers; @@ -340,15 +354,21 @@ void coroutine_fn throttle_group_co_io_limits_intercept(BlockBackend *blk, qemu_mutex_unlock(&tg->lock); } -static void throttle_group_restart_queue(BlockBackend *blk, bool is_write) +typedef struct { + BlockBackend *blk; + bool is_write; +} RestartData; + +static void coroutine_fn throttle_group_restart_queue_entry(void *opaque) { + RestartData *data = opaque; + BlockBackend *blk = data->blk; + bool is_write = data->is_write; BlockBackendPublic *blkp = blk_get_public(blk); ThrottleGroup *tg = container_of(blkp->throttle_state, ThrottleGroup, ts); bool empty_queue; - aio_context_acquire(blk_get_aio_context(blk)); - empty_queue = !qemu_co_enter_next(&blkp->throttled_reqs[is_write]); - aio_context_release(blk_get_aio_context(blk)); + empty_queue = !throttle_group_co_restart_queue(blk, is_write); /* If the request queue was empty then we have to take care of * scheduling the next one */ @@ -359,6 +379,18 @@ static void throttle_group_restart_queue(BlockBackend *blk, bool is_write) } } +static void throttle_group_restart_queue(BlockBackend *blk, bool is_write) +{ + Coroutine *co; + RestartData rd = { + .blk = blk, + .is_write = is_write + }; + + co = qemu_coroutine_create(throttle_group_restart_queue_entry, &rd); + aio_co_enter(blk_get_aio_context(blk), co); +} + void throttle_group_restart_blk(BlockBackend *blk) { BlockBackendPublic *blkp = blk_get_public(blk); -- 2.12.2