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From: Tejun Heo <tj@kernel.org>
To: Shaohua Li <shli@fb.com>
Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
	kernel-team@fb.com, axboe@fb.com, vgoyal@redhat.com
Subject: Re: [PATCH V5 08/17] blk-throttle: make throtl_slice tunable
Date: Mon, 9 Jan 2017 15:08:43 -0500	[thread overview]
Message-ID: <20170109200843.GL12827@mtj.duckdns.org> (raw)
In-Reply-To: <3341ed56034ecbcdaaaa63a87345ea7f16178339.1481833017.git.shli@fb.com>

Hello,

On Thu, Dec 15, 2016 at 12:32:59PM -0800, Shaohua Li wrote:
> throtl_slice is important for blk-throttling. It's called slice
> internally but it really is a time window blk-throttling samples data.
> blk-throttling will make decision based on the samplings. An example is
> bandwidth measurement. A cgroup's bandwidth is measured in the time
> interval of throtl_slice.
> 
> A small throtl_slice meanse cgroups have smoother throughput but burn
> more CPUs. It has 100ms default value, which is not appropriate for all
> disks. A fast SSD can dispatch a lot of IOs in 100ms. This patch makes
> it tunable.
> 
> Since throtl_slice isn't a time slice, the sysfs name
> 'throttle_sample_time' reflects its character better.

Generally looks good.  I think some documentation would be great.
Also, do we wannt set it to a lower number if blk_queue_nonrot()?

Thanks.

-- 
tejun

  reply	other threads:[~2017-01-09 20:08 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-12-15 20:32 [PATCH V5 00/17] blk-throttle: add .low limit Shaohua Li
2016-12-15 20:32 ` [PATCH V5 01/17] blk-throttle: use U64_MAX/UINT_MAX to replace -1 Shaohua Li
2016-12-15 20:32 ` [PATCH V5 02/17] blk-throttle: prepare support multiple limits Shaohua Li
2016-12-15 20:32 ` [PATCH V5 03/17] blk-throttle: add .low interface Shaohua Li
2017-01-09 16:35   ` Tejun Heo
2016-12-15 20:32 ` [PATCH V5 04/17] blk-throttle: configure bps/iops limit for cgroup in low limit Shaohua Li
2017-01-09 17:35   ` Tejun Heo
2016-12-15 20:32 ` [PATCH V5 05/17] blk-throttle: add upgrade logic for LIMIT_LOW state Shaohua Li
2017-01-09 18:40   ` Tejun Heo
2017-01-09 19:46     ` Tejun Heo
2016-12-15 20:32 ` [PATCH V5 06/17] blk-throttle: add downgrade logic Shaohua Li
2016-12-15 20:32 ` [PATCH V5 07/17] blk-throttle: make sure expire time isn't too big Shaohua Li
2017-01-09 19:54   ` Tejun Heo
2016-12-15 20:32 ` [PATCH V5 08/17] blk-throttle: make throtl_slice tunable Shaohua Li
2017-01-09 20:08   ` Tejun Heo [this message]
2016-12-15 20:33 ` [PATCH V5 09/17] blk-throttle: detect completed idle cgroup Shaohua Li
2017-01-09 20:13   ` Tejun Heo
2016-12-15 20:33 ` [PATCH V5 10/17] blk-throttle: make bandwidth change smooth Shaohua Li
2017-01-09 20:28   ` Tejun Heo
2016-12-15 20:33 ` [PATCH V5 11/17] blk-throttle: add a simple idle detection Shaohua Li
2017-01-09 20:56   ` Tejun Heo
2016-12-15 20:33 ` [PATCH V5 12/17] blk-throttle: add interface to configure idle time threshold Shaohua Li
2017-01-09 20:58   ` Tejun Heo
2016-12-15 20:33 ` [PATCH V5 13/17] blk-throttle: ignore idle cgroup limit Shaohua Li
2017-01-09 21:01   ` Tejun Heo
2016-12-15 20:33 ` [PATCH V5 14/17] blk-throttle: add interface for per-cgroup target latency Shaohua Li
2017-01-09 21:14   ` Tejun Heo
2016-12-15 20:33 ` [PATCH V5 15/17] block: track request size in blk_issue_stat Shaohua Li
2016-12-16  2:01   ` kbuild test robot
2017-01-09 21:17   ` Tejun Heo
2016-12-15 20:33 ` [PATCH V5 16/17] blk-throttle: add a mechanism to estimate IO latency Shaohua Li
2017-01-09 21:39   ` Tejun Heo
2016-12-15 20:33 ` [PATCH V5 17/17] blk-throttle: add latency target support Shaohua Li
2017-01-09 21:46 ` [PATCH V5 00/17] blk-throttle: add .low limit Tejun Heo
2017-01-09 22:27   ` Shaohua Li

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