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[Qemu-devel] [PATCH 08/17] throttle-groups: protect throttled requests w
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PATCH 08/17] throttle-groups: protect throttled requests with a CoMutex |
Date: |
Thu, 20 Apr 2017 14:00:49 +0200 |
Signed-off-by: Paolo Bonzini <address@hidden>
---
block/block-backend.c | 1 +
block/throttle-groups.c | 11 +++++++++--
include/sysemu/block-backend.h | 7 ++-----
3 files changed, 12 insertions(+), 7 deletions(-)
diff --git a/block/block-backend.c b/block/block-backend.c
index 915ccc5..a37d74d 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -163,6 +163,7 @@ BlockBackend *blk_new(uint64_t perm, uint64_t shared_perm)
blk->shared_perm = shared_perm;
blk_set_enable_write_cache(blk, true);
+ qemu_co_mutex_init(&blk->public.reqs_lock);
qemu_co_queue_init(&blk->public.throttled_reqs[0]);
qemu_co_queue_init(&blk->public.throttled_reqs[1]);
diff --git a/block/throttle-groups.c b/block/throttle-groups.c
index d66bf62..695d28d 100644
--- a/block/throttle-groups.c
+++ b/block/throttle-groups.c
@@ -268,8 +268,13 @@ static bool throttle_group_schedule_timer(BlockBackend
*blk, bool is_write)
static bool throttle_group_co_restart_queue(BlockBackend *blk, bool is_write)
{
BlockBackendPublic *blkp = blk_get_public(blk);
+ bool ret;
- return qemu_co_queue_next(&blkp->throttled_reqs[is_write]);
+ qemu_co_mutex_lock(&blkp->reqs_lock);
+ ret = qemu_co_queue_next(&blkp->throttled_reqs[is_write]);
+ qemu_co_mutex_unlock(&blkp->reqs_lock);
+
+ return ret;
}
/* Look for the next pending I/O request and schedule it.
@@ -338,7 +343,9 @@ void coroutine_fn
throttle_group_co_io_limits_intercept(BlockBackend *blk,
if (must_wait || blkp->pending_reqs[is_write]) {
blkp->pending_reqs[is_write]++;
qemu_mutex_unlock(&tg->lock);
- qemu_co_queue_wait(&blkp->throttled_reqs[is_write], NULL);
+ qemu_co_mutex_lock(&blkp->reqs_lock);
+ qemu_co_queue_wait(&blkp->throttled_reqs[is_write], &blkp->reqs_lock);
+ qemu_co_mutex_unlock(&blkp->reqs_lock);
qemu_mutex_lock(&tg->lock);
blkp->pending_reqs[is_write]--;
}
diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h
index 87a43b0..e9529fb 100644
--- a/include/sysemu/block-backend.h
+++ b/include/sysemu/block-backend.h
@@ -72,11 +72,8 @@ typedef struct BlockDevOps {
* fields that must be public. This is in particular for QLIST_ENTRY() and
* friends so that BlockBackends can be kept in lists outside block-backend.c
*/
typedef struct BlockBackendPublic {
- /* I/O throttling has its own locking, but also some fields are
- * protected by the AioContext lock.
- */
-
- /* Protected by AioContext lock. */
+ /* reqs_lock protects the CoQueues for throttled requests. */
+ CoMutex reqs_lock;
CoQueue throttled_reqs[2];
/* Nonzero if the I/O limits are currently being ignored; generally
--
2.9.3
- [Qemu-devel] [PATCH 01/17] block: access copy_on_read with atomic ops, (continued)
- [Qemu-devel] [PATCH 01/17] block: access copy_on_read with atomic ops, Paolo Bonzini, 2017/04/20
- [Qemu-devel] [PATCH 13/17] coroutine-lock: introduce qemu_co_mutex_lock_unlock, Paolo Bonzini, 2017/04/20
- [Qemu-devel] [PATCH 09/17] util: add stats64 module, Paolo Bonzini, 2017/04/20
- [Qemu-devel] [PATCH 14/17] block: optimize access to reqs_lock, Paolo Bonzini, 2017/04/20
- [Qemu-devel] [PATCH 03/17] block: access io_limits_disabled with atomic ops, Paolo Bonzini, 2017/04/20
- [Qemu-devel] [PATCH 02/17] block: access quiesce_counter with atomic ops, Paolo Bonzini, 2017/04/20
- [Qemu-devel] [PATCH 04/17] block: access serialising_in_flight with atomic ops, Paolo Bonzini, 2017/04/20
- [Qemu-devel] [PATCH 10/17] block: use Stat64 for wr_highest_offset, Paolo Bonzini, 2017/04/20
- [Qemu-devel] [PATCH 15/17] block: introduce dirty_bitmap_mutex, Paolo Bonzini, 2017/04/20
- [Qemu-devel] [PATCH 17/17] block: make accounting thread-safe, Paolo Bonzini, 2017/04/20
- [Qemu-devel] [PATCH 08/17] throttle-groups: protect throttled requests with a CoMutex,
Paolo Bonzini <=
- [Qemu-devel] [PATCH 12/17] block: protect tracked_requests and flush_queue with reqs_lock, Paolo Bonzini, 2017/04/20
- [Qemu-devel] [PATCH 16/17] block: protect modification of dirty bitmaps with a mutex, Paolo Bonzini, 2017/04/20
- Re: [Qemu-devel] [PATCH for 2.10 00/17] Block layer thread safety, part 1, no-reply, 2017/04/20
- Re: [Qemu-devel] [PATCH for 2.10 00/17] Block layer thread safety, part 1, no-reply, 2017/04/20