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From: Jens Axboe <axboe@kernel.dk>
To: Tejun Heo <tj@kernel.org>
Cc: linux-block@vger.kernel.org, kernel-team@fb.com,
	linux-kernel@vger.kernel.org, cgroups@vger.kernel.org,
	Josef Bacik <josef@toxicpanda.com>
Subject: Re: [PATCH block/for-5.5-fixes] iocost: over-budget forced IOs should schedule async delay
Date: Mon, 16 Dec 2019 16:10:32 -0700	[thread overview]
Message-ID: <fc474a2f-4e1b-8c9f-06bf-b479f7455c77@kernel.dk> (raw)
In-Reply-To: <20191216213400.GA2914998@devbig004.ftw2.facebook.com>

On 12/16/19 2:34 PM, Tejun Heo wrote:
> When over-budget IOs are force-issued through root cgroup,
> iocg_kick_delay() adjusts the async delay accordingly but doesn't
> actually schedule async throttle for the issuing task.  This bug is
> pretty well masked because sooner or later the offending threads are
> gonna get directly throttled on regular IOs or have async delay
> scheduled by mem_cgroup_throttle_swaprate().
> 
> However, it can affect control quality on filesystem metadata heavy
> operations.  Let's fix it by invoking blkcg_schedule_throttle() when
> iocg_kick_delay() says async delay is needed.

Applied, thanks Tejun.

-- 
Jens Axboe


      reply	other threads:[~2019-12-16 23:10 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-16 21:34 [PATCH block/for-5.5-fixes] iocost: over-budget forced IOs should schedule async delay Tejun Heo
2019-12-16 23:10 ` Jens Axboe [this message]

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