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| author | Tejun Heo <tj@kernel.org> | 2014-09-24 21:07:33 +0400 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2014-09-24 21:07:33 +0400 |
| commit | 9eca80461a45177e456219a9cd944c27675d6512 (patch) | |
| tree | 88652d4a20e98ba2bc503e110edf45c94a3f6699 | |
| parent | d06efebf0c37d438fcf07057be00dd40fcfce08d (diff) | |
| download | linux-9eca80461a45177e456219a9cd944c27675d6512.tar.xz | |
Revert "blk-mq, percpu_ref: implement a kludge for SCSI blk-mq stall during probe"
This reverts commit 0a30288da1aec914e158c2d7a3482a85f632750f, which
was a temporary fix for SCSI blk-mq stall issue. The following
patches will fix the issue properly by introducing atomic mode to
percpu_ref.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>
| -rw-r--r-- | block/blk-mq.c | 11 | ||||
| -rw-r--r-- | include/linux/percpu-refcount.h | 1 | ||||
| -rw-r--r-- | lib/percpu-refcount.c | 16 |
3 files changed, 1 insertions, 27 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index 255d79c14dc1..44a78ae3f899 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -119,16 +119,7 @@ void blk_mq_freeze_queue(struct request_queue *q) spin_unlock_irq(q->queue_lock); if (freeze) { - /* - * XXX: Temporary kludge to work around SCSI blk-mq stall. - * SCSI synchronously creates and destroys many queues - * back-to-back during probe leading to lengthy stalls. - * This will be fixed by keeping ->mq_usage_counter in - * atomic mode until genhd registration, but, for now, - * let's work around using expedited synchronization. - */ - __percpu_ref_kill_expedited(&q->mq_usage_counter); - + percpu_ref_kill(&q->mq_usage_counter); blk_mq_run_queues(q, false); } wait_event(q->mq_freeze_wq, percpu_ref_is_zero(&q->mq_usage_counter)); diff --git a/include/linux/percpu-refcount.h b/include/linux/percpu-refcount.h index 11b38ceca7e2..5df6784bd9d2 100644 --- a/include/linux/percpu-refcount.h +++ b/include/linux/percpu-refcount.h @@ -72,7 +72,6 @@ void percpu_ref_reinit(struct percpu_ref *ref); void percpu_ref_exit(struct percpu_ref *ref); void percpu_ref_kill_and_confirm(struct percpu_ref *ref, percpu_ref_func_t *confirm_kill); -void __percpu_ref_kill_expedited(struct percpu_ref *ref); /** * percpu_ref_kill - drop the initial ref diff --git a/lib/percpu-refcount.c b/lib/percpu-refcount.c index c6c31e2829b1..559ee0b20318 100644 --- a/lib/percpu-refcount.c +++ b/lib/percpu-refcount.c @@ -189,19 +189,3 @@ void percpu_ref_kill_and_confirm(struct percpu_ref *ref, call_rcu_sched(&ref->rcu, percpu_ref_kill_rcu); } EXPORT_SYMBOL_GPL(percpu_ref_kill_and_confirm); - -/* - * XXX: Temporary kludge to work around SCSI blk-mq stall. Used only by - * block/blk-mq.c::blk_mq_freeze_queue(). Will be removed during v3.18 - * devel cycle. Do not use anywhere else. - */ -void __percpu_ref_kill_expedited(struct percpu_ref *ref) -{ - WARN_ONCE(ref->pcpu_count_ptr & PCPU_REF_DEAD, - "percpu_ref_kill() called more than once on %pf!", - ref->release); - - ref->pcpu_count_ptr |= PCPU_REF_DEAD; - synchronize_sched_expedited(); - percpu_ref_kill_rcu(&ref->rcu); -} |