From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43245) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V1fRM-0004f2-9p for qemu-devel@nongnu.org; Tue, 23 Jul 2013 12:28:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1V1fRI-0000Fm-Ei for qemu-devel@nongnu.org; Tue, 23 Jul 2013 12:27:56 -0400 Received: from nodalink.pck.nerim.net ([62.212.105.220]:47655 helo=paradis.irqsave.net) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V1fRH-0000Fd-TP for qemu-devel@nongnu.org; Tue, 23 Jul 2013 12:27:52 -0400 From: =?UTF-8?q?Beno=C3=AEt=20Canet?= Date: Tue, 23 Jul 2013 18:29:24 +0200 Message-Id: <1374596968-20181-2-git-send-email-benoit@irqsave.net> In-Reply-To: <1374596968-20181-1-git-send-email-benoit@irqsave.net> References: <1374596968-20181-1-git-send-email-benoit@irqsave.net> Subject: [Qemu-devel] [PATCH V3 for-1.6 1/5] block: Repair the throttling code. List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kwolf@redhat.com, =?UTF-8?q?Beno=C3=AEt=20Canet?= , stefanha@redhat.com The throttling code was segfaulting since commit 02ffb504485f0920cfc75a0982a602f824a9a4f4 because some qemu_co_queue_next caller does not run in a coroutine. qemu_co_queue_do_restart assume that the caller is a coroutinne. As suggested by Stefan fix this by entering the coroutine directly. Also make sure like suggested that qemu_co_queue_next() and qemu_co_queue_restart_all() can be called only in coroutines. Signed-off-by: Benoit Canet --- block.c | 8 ++++---- include/block/coroutine.h | 9 +++++++-- qemu-coroutine-lock.c | 20 ++++++++++++++++++-- 3 files changed, 29 insertions(+), 8 deletions(-) diff --git a/block.c b/block.c index b560241..dc72643 100644 --- a/block.c +++ b/block.c @@ -127,7 +127,8 @@ void bdrv_io_limits_disable(BlockDriverState *bs) { bs->io_limits_enabled = false; - while (qemu_co_queue_next(&bs->throttled_reqs)); + while (qemu_co_enter_next(&bs->throttled_reqs)) { + } if (bs->block_timer) { qemu_del_timer(bs->block_timer); @@ -143,7 +144,7 @@ static void bdrv_block_timer(void *opaque) { BlockDriverState *bs = opaque; - qemu_co_queue_next(&bs->throttled_reqs); + qemu_co_enter_next(&bs->throttled_reqs); } void bdrv_io_limits_enable(BlockDriverState *bs) @@ -1445,8 +1446,7 @@ void bdrv_drain_all(void) * a busy wait. */ QTAILQ_FOREACH(bs, &bdrv_states, list) { - if (!qemu_co_queue_empty(&bs->throttled_reqs)) { - qemu_co_queue_restart_all(&bs->throttled_reqs); + while (qemu_co_enter_next(&bs->throttled_reqs)) { busy = true; } } diff --git a/include/block/coroutine.h b/include/block/coroutine.h index 377805a..1f2db3e 100644 --- a/include/block/coroutine.h +++ b/include/block/coroutine.h @@ -130,12 +130,17 @@ void coroutine_fn qemu_co_queue_wait_insert_head(CoQueue *queue); * * Returns true if a coroutine was restarted, false if the queue is empty. */ -bool qemu_co_queue_next(CoQueue *queue); +bool coroutine_fn qemu_co_queue_next(CoQueue *queue); /** * Restarts all coroutines in the CoQueue and leaves the queue empty. */ -void qemu_co_queue_restart_all(CoQueue *queue); +void coroutine_fn qemu_co_queue_restart_all(CoQueue *queue); + +/** + * Enter the next coroutine in the queue + */ +bool qemu_co_enter_next(CoQueue *queue); /** * Checks if the CoQueue is empty. diff --git a/qemu-coroutine-lock.c b/qemu-coroutine-lock.c index d9fea49..aeb33b9 100644 --- a/qemu-coroutine-lock.c +++ b/qemu-coroutine-lock.c @@ -88,16 +88,32 @@ static bool qemu_co_queue_do_restart(CoQueue *queue, bool single) return true; } -bool qemu_co_queue_next(CoQueue *queue) +bool coroutine_fn qemu_co_queue_next(CoQueue *queue) { + assert(qemu_in_coroutine()); return qemu_co_queue_do_restart(queue, true); } -void qemu_co_queue_restart_all(CoQueue *queue) +void coroutine_fn qemu_co_queue_restart_all(CoQueue *queue) { + assert(qemu_in_coroutine()); qemu_co_queue_do_restart(queue, false); } +bool qemu_co_enter_next(CoQueue *queue) +{ + Coroutine *next; + + next = QTAILQ_FIRST(&queue->entries); + if (!next) { + return false; + } + + QTAILQ_REMOVE(&queue->entries, next, co_queue_next); + qemu_coroutine_enter(next, NULL); + return true; +} + bool qemu_co_queue_empty(CoQueue *queue) { return (QTAILQ_FIRST(&queue->entries) == NULL); -- 1.7.10.4