From: Omar Sandoval <osandov@osandov.com>
To: Ilya Dryomov <idryomov@gmail.com>
Cc: linux-block@vger.kernel.org, Jens Axboe <axboe@fb.com>,
Bart Van Assche <bvanassche@acm.org>,
Omar Sandoval <osandov@fb.com>
Subject: Re: [PATCH] blk-mq: I/O and timer unplugs are inverted in blktrace
Date: Thu, 27 Sep 2018 12:09:28 -0700 [thread overview]
Message-ID: <20180927190928.GB29754@vader> (raw)
In-Reply-To: <20180926123550.16311-1-idryomov@gmail.com>
On Wed, Sep 26, 2018 at 02:35:50PM +0200, Ilya Dryomov wrote:
> trace_block_unplug() takes true for explicit unplugs and false for
> implicit unplugs. schedule() unplugs are implicit and should be
> reported as timer unplugs. While correct in the legacy code, this has
> been inverted in blk-mq since 4.11.
>
> Cc: stable@vger.kernel.org
> Fixes: bd166ef183c2 ("blk-mq-sched: add framework for MQ capable IO schedulers")
Reviewed-by: Omar Sandoval <osandov@fb.com>
> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
> ---
> block/blk-mq.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/block/blk-mq.c b/block/blk-mq.c
> index 85a1c1a59c72..e3c39ea8e17b 100644
> --- a/block/blk-mq.c
> +++ b/block/blk-mq.c
> @@ -1628,7 +1628,7 @@ void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule)
> BUG_ON(!rq->q);
> if (rq->mq_ctx != this_ctx) {
> if (this_ctx) {
> - trace_block_unplug(this_q, depth, from_schedule);
> + trace_block_unplug(this_q, depth, !from_schedule);
> blk_mq_sched_insert_requests(this_q, this_ctx,
> &ctx_list,
> from_schedule);
> @@ -1648,7 +1648,7 @@ void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule)
> * on 'ctx_list'. Do those.
> */
> if (this_ctx) {
> - trace_block_unplug(this_q, depth, from_schedule);
> + trace_block_unplug(this_q, depth, !from_schedule);
> blk_mq_sched_insert_requests(this_q, this_ctx, &ctx_list,
> from_schedule);
> }
> --
> 2.14.4
>
next prev parent reply other threads:[~2018-09-28 1:29 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-26 12:35 [PATCH] blk-mq: I/O and timer unplugs are inverted in blktrace Ilya Dryomov
2018-09-27 19:09 ` Omar Sandoval [this message]
2018-09-27 19:12 ` Jens Axboe
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