From: "Darrick J. Wong" <darrick.wong@oracle.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>,
linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-api@vger.kernel.org,
Dmitry Monakhov <dmtrmonakhov@yandex-team.ru>
Subject: Re: [PATCH] block: add iostat counters for flush requests
Date: Thu, 21 Nov 2019 08:04:30 -0800 [thread overview]
Message-ID: <20191121160430.GJ6211@magnolia> (raw)
In-Reply-To: <ff971ff6-9a10-c3f1-107d-4f7d378e8755@kernel.dk>
On Thu, Nov 21, 2019 at 08:56:14AM -0700, Jens Axboe wrote:
> On 11/21/19 3:40 AM, Konstantin Khlebnikov wrote:
> > Requests that triggers flushing volatile writeback cache to disk (barriers)
> > have significant effect to overall performance.
> >
> > Block layer has sophisticated engine for combining several flush requests
> > into one. But there is no statistics for actual flushes executed by disk.
> > Requests which trigger flushes usually are barriers - zero-size writes.
> >
> > This patch adds two iostat counters into /sys/class/block/$dev/stat and
> > /proc/diskstats - count of completed flush requests and their total time.
>
> This makes sense to me, and the "recent" discard addition already proved
> that we're fine extending with more fields. Unless folks object, I'd be
> happy to queue this up for 5.5.
Looks like a good addition to /me... :)
--D
> --
> Jens Axboe
>
next prev parent reply other threads:[~2019-11-21 16:04 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-21 10:40 [PATCH] block: add iostat counters for flush requests Konstantin Khlebnikov
2019-11-21 15:56 ` Jens Axboe
2019-11-21 16:04 ` Darrick J. Wong [this message]
2019-11-21 16:07 ` Jens Axboe
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