From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38626) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d1Aml-0007ab-Nu for qemu-devel@nongnu.org; Thu, 20 Apr 2017 08:02:12 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d1Amf-00033B-Lv for qemu-devel@nongnu.org; Thu, 20 Apr 2017 08:02:07 -0400 From: Paolo Bonzini Date: Thu, 20 Apr 2017 14:00:44 +0200 Message-Id: <20170420120058.28404-4-pbonzini@redhat.com> In-Reply-To: <20170420120058.28404-1-pbonzini@redhat.com> References: <20170420120058.28404-1-pbonzini@redhat.com> Subject: [Qemu-devel] [PATCH 03/17] block: access io_limits_disabled with atomic ops List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: qemu-block@nongnu.org Signed-off-by: Paolo Bonzini --- block/block-backend.c | 4 ++-- block/throttle-groups.c | 2 +- include/sysemu/block-backend.h | 3 ++- 3 files changed, 5 insertions(+), 4 deletions(-) diff --git a/block/block-backend.c b/block/block-backend.c index 7405024..915ccc5 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -1927,7 +1927,7 @@ static void blk_root_drained_begin(BdrvChild *child) /* Note that blk->root may not be accessible here yet if we are just * attaching to a BlockDriverState that is drained. Use child instead. */ - if (blk->public.io_limits_disabled++ == 0) { + if (atomic_fetch_inc(&blk->public.io_limits_disabled) == 0) { throttle_group_restart_blk(blk); } } @@ -1938,7 +1938,7 @@ static void blk_root_drained_end(BdrvChild *child) assert(blk->quiesce_counter); assert(blk->public.io_limits_disabled); - --blk->public.io_limits_disabled; + atomic_dec(&blk->public.io_limits_disabled); if (--blk->quiesce_counter == 0) { if (blk->dev_ops && blk->dev_ops->drained_end) { diff --git a/block/throttle-groups.c b/block/throttle-groups.c index b73e7a8..69bfbd4 100644 --- a/block/throttle-groups.c +++ b/block/throttle-groups.c @@ -240,7 +240,7 @@ static bool throttle_group_schedule_timer(BlockBackend *blk, bool is_write) ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts); bool must_wait; - if (blkp->io_limits_disabled) { + if (atomic_read(&blkp->io_limits_disabled)) { return false; } diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h index 7462228..87a43b0 100644 --- a/include/sysemu/block-backend.h +++ b/include/sysemu/block-backend.h @@ -80,7 +80,8 @@ typedef struct BlockBackendPublic { CoQueue throttled_reqs[2]; /* Nonzero if the I/O limits are currently being ignored; generally - * it is zero. */ + * it is zero. Accessed with atomic operations. + */ unsigned int io_limits_disabled; /* The following fields are protected by the ThrottleGroup lock. -- 2.9.3