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From: Song Liu <song@kernel.org>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org,
	linux-raid <linux-raid@vger.kernel.org>,
	stable@vger.kernel.org, Larkin Lowrey <llowrey@nuclearwinter.com>,
	Wilson Jonathan <i400sjon@gmail.com>,
	Roger Heflin <rogerheflin@gmail.com>
Subject: Re: [PATCH] block: check more requests for multiple_queues in blk_attempt_plug_merge
Date: Fri, 11 Mar 2022 08:59:05 -0800	[thread overview]
Message-ID: <CAPhsuW492+zrVCyckgct_ju+5V_2grn4-s--TU2QVA7pkYtyzA@mail.gmail.com> (raw)
In-Reply-To: <84310ba2-a413-22f4-1349-59a09f4851a1@kernel.dk>

Hi Jens,

On Fri, Mar 11, 2022 at 6:16 AM Jens Axboe <axboe@kernel.dk> wrote:
>
> On 3/10/22 5:07 PM, Jens Axboe wrote:
> > In any case, just doing larger reads would likely help quite a bit, but
> > would still be nice to get to the bottom of why we're not seeing the
> > level of merging we expect.
>
> Song, can you try this one? It'll do the dispatch in a somewhat saner
> fashion, bundling identical queues. And we'll keep iterating the plug
> list for a merge if we have multiple disks, until we've seen a queue
> match and checked.

This one works great! We are seeing 99% read request merge and
500kB+ average read size. The original patch in this thread only got
88% and 34kB for these two metrics.

Thanks,
Song

[...]

  reply	other threads:[~2022-03-11 16:59 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-09  6:42 [PATCH] block: check more requests for multiple_queues in blk_attempt_plug_merge Song Liu
2022-03-10  6:48 ` Christoph Hellwig
2022-03-10  7:23   ` Song Liu
2022-03-10 22:10     ` Song Liu
2022-03-10 22:12       ` Song Liu
2022-03-10 22:15 ` Jens Axboe
2022-03-10 22:37   ` Song Liu
2022-03-10 23:02     ` Jens Axboe
2022-03-10 23:33       ` Song Liu
2022-03-11  0:07         ` Jens Axboe
2022-03-11  0:31           ` Song Liu
2022-03-11  0:36             ` Jens Axboe
2022-03-11  0:38               ` Jens Axboe
2022-03-11  1:14               ` Ming Lei
2022-03-11  1:21                 ` Jens Axboe
2022-03-11  1:32                   ` Ming Lei
2022-03-11  1:35                     ` Jens Axboe
2022-03-11  8:09                       ` Wols Lists
2022-03-11 14:16           ` Jens Axboe
2022-03-11 16:59             ` Song Liu [this message]
2022-03-11 21:41               ` Paul Menzel
2022-03-11 22:40                 ` Song Liu
2022-03-11 11:30     ` Wilson Jonathan
2022-03-11 15:58       ` Wols Lists

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