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From: xuejiufei <xuejiufei@gmail.com>
To: Tejun Heo <tj@kernel.org>, Jens Axboe <axboe@fb.com>,
	Shaohua Li <shli@kernel.org>
Cc: linux-block@vger.kernel.org, cgroups@vger.kernel.org
Subject: [RFC] distinguish foreground and background IOs in block throttle
Date: Mon, 25 Dec 2017 10:44:26 +0800	[thread overview]
Message-ID: <1fa623a6-e374-de5e-477e-e604cb760f82@gmail.com> (raw)

Hi all,

Cgroup writeback is supported since v4.2. I found there exists a
problem in the following case.

A cgroup may send both buffer and direct/sync IOs. The foreground
thread will be stalled when periodic writeback IOs is flushed because
the service queue already has a plenty of writeback IOs, then
foreground IOs should be enqueued with its FIFO policy.

I wonder if we can distinguish foreground and background IOs in block
throttle to fix the above problem.

Any suggestion are always appreciated.


Thanks,
Jiufei

             reply	other threads:[~2017-12-25  2:44 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-12-25  2:44 xuejiufei [this message]
2017-12-27 12:36 ` [RFC] distinguish foreground and background IOs in block throttle Paolo Valente
     [not found]   ` <A491ADB3-5487-4161-A526-E0C3AF416437-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
2017-12-28  1:51     ` Joseph Qi
2017-12-28  8:48       ` Paolo Valente

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