From: Ming Lei <ming.lei@redhat.com>
To: Omar Sandoval <osandov@osandov.com>
Cc: Jens Axboe <axboe@fb.com>,
linux-block@vger.kernel.org,
Christoph Hellwig <hch@infradead.org>,
Bart Van Assche <bart.vanassche@sandisk.com>,
Laurence Oberman <loberman@redhat.com>,
Paolo Valente <paolo.valente@linaro.org>,
Mel Gorman <mgorman@techsingularity.net>
Subject: Re: [PATCH V4 00/14] blk-mq-sched: improve SCSI-MQ performance
Date: Wed, 20 Sep 2017 11:18:11 +0800 [thread overview]
Message-ID: <20170920031810.GA24489@ming.t460p> (raw)
In-Reply-To: <20170919192515.GC31219@vader.DHCP.thefacebook.com>
On Tue, Sep 19, 2017 at 12:25:15PM -0700, Omar Sandoval wrote:
> On Sat, Sep 02, 2017 at 11:17:15PM +0800, Ming Lei wrote:
> > Hi,
> >
> > In Red Hat internal storage test wrt. blk-mq scheduler, we
> > found that I/O performance is much bad with mq-deadline, especially
> > about sequential I/O on some multi-queue SCSI devcies(lpfc, qla2xxx,
> > SRP...)
> >
> > Turns out one big issue causes the performance regression: requests
> > are still dequeued from sw queue/scheduler queue even when ldd's
> > queue is busy, so I/O merge becomes quite difficult to make, then
> > sequential IO degrades a lot.
> >
> > The 1st five patches improve this situation, and brings back
> > some performance loss.
>
> Sorry it took so long, I've reviewed or commented on patches 1-6. When
> you send v5, could you just send patches 1-6, and split the rest as
> their own series?
Sure, no problem.
Thanks for your review!
--
Ming
next prev parent reply other threads:[~2017-09-20 3:18 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-02 15:17 [PATCH V4 00/14] blk-mq-sched: improve SCSI-MQ performance Ming Lei
2017-09-02 15:17 ` [PATCH V4 01/14] blk-mq-sched: fix scheduler bad performance Ming Lei
2017-09-08 20:48 ` Omar Sandoval
2017-09-08 20:54 ` Omar Sandoval
2017-09-08 20:56 ` Omar Sandoval
2017-09-09 7:43 ` Ming Lei
2017-09-09 7:33 ` Ming Lei
2017-09-02 15:17 ` [PATCH V4 02/14] sbitmap: introduce __sbitmap_for_each_set() Ming Lei
2017-09-08 20:43 ` Omar Sandoval
2017-09-09 9:38 ` Ming Lei
2017-09-10 17:20 ` Omar Sandoval
2017-09-11 4:08 ` Ming Lei
2017-09-13 18:37 ` Omar Sandoval
2017-09-14 1:56 ` Ming Lei
2017-09-14 14:59 ` Omar Sandoval
2017-09-14 15:18 ` Omar Sandoval
2017-09-15 1:57 ` Ming Lei
2017-09-02 15:17 ` [PATCH V4 03/14] blk-mq: introduce blk_mq_dispatch_rq_from_ctx() Ming Lei
2017-09-15 0:04 ` Omar Sandoval
2017-09-15 1:50 ` Ming Lei
2017-09-02 15:17 ` [PATCH V4 04/14] blk-mq-sched: move actual dispatching into one helper Ming Lei
2017-09-19 19:21 ` Omar Sandoval
2017-09-02 15:17 ` [PATCH V4 05/14] blk-mq-sched: improve dispatching from sw queue Ming Lei
2017-09-08 23:54 ` Omar Sandoval
2017-09-10 4:45 ` Ming Lei
2017-09-10 17:38 ` Omar Sandoval
2017-09-11 4:13 ` Ming Lei
2017-09-13 17:32 ` Omar Sandoval
2017-09-19 20:37 ` Jens Axboe
2017-09-20 2:37 ` Ming Lei
2017-09-20 12:20 ` Ming Lei
2017-09-22 2:15 ` Ming Lei
2017-09-02 15:17 ` [PATCH V4 06/14] blk-mq-sched: don't dequeue request until all in ->dispatch are flushed Ming Lei
2017-09-19 19:11 ` Omar Sandoval
2017-09-20 2:55 ` Ming Lei
2017-09-02 15:17 ` [PATCH V4 07/14] blk-mq-sched: introduce blk_mq_sched_queue_depth() Ming Lei
2017-09-02 15:17 ` [PATCH V4 08/14] blk-mq-sched: use q->queue_depth as hint for q->nr_requests Ming Lei
2017-09-02 15:17 ` [PATCH V4 09/14] block: introduce rqhash helpers Ming Lei
2017-09-02 15:17 ` [PATCH V4 10/14] block: move actual bio merge code into __elv_merge Ming Lei
2017-09-02 15:17 ` [PATCH V4 11/14] block: add check on elevator for supporting bio merge via hashtable from blk-mq sw queue Ming Lei
2017-09-02 15:17 ` [PATCH V4 12/14] block: introduce .last_merge and .hash to blk_mq_ctx Ming Lei
2017-09-02 15:17 ` [PATCH V4 13/14] blk-mq-sched: refactor blk_mq_sched_try_merge() Ming Lei
2017-09-02 15:17 ` [PATCH V4 14/14] blk-mq: improve bio merge from blk-mq sw queue Ming Lei
2017-09-04 9:12 ` [PATCH V4 00/14] blk-mq-sched: improve SCSI-MQ performance Paolo Valente
2017-09-05 1:39 ` Ming Lei
2017-09-06 15:27 ` Ming Lei
2017-09-19 19:25 ` Omar Sandoval
2017-09-20 3:18 ` Ming Lei [this message]
-- strict thread matches above, loose matches on Subject: below --
2017-09-06 21:09 Oleksandr Natalenko
2017-09-06 21:22 ` Tom Nguyen
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