From: "Austin S. Hemmelgarn" <ahferroin7@gmail.com>
To: Mark Brown <broonie@kernel.org>,
Linus Walleij <linus.walleij@linaro.org>
Cc: Tejun Heo <tj@kernel.org>,
Paolo Valente <paolo.valente@unimore.it>,
Shaohua Li <shli@fb.com>, Vivek Goyal <vgoyal@redhat.com>,
linux-block@vger.kernel.org,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Jens Axboe <axboe@fb.com>,
Kernel-team@fb.com, jmoyer@redhat.com,
Ulf Hansson <ulf.hansson@linaro.org>,
Hannes Reinecke <hare@suse.com>
Subject: Re: [PATCH V3 00/11] block-throttle: add .high limit
Date: Thu, 6 Oct 2016 07:57:37 -0400 [thread overview]
Message-ID: <439e8a13-cb14-c955-ae98-30ed5490739b@gmail.com> (raw)
In-Reply-To: <20161006110342.gyyiwaqw4ivzdaww@sirena.org.uk>
On 2016-10-06 07:03, Mark Brown wrote:
> On Thu, Oct 06, 2016 at 10:04:41AM +0200, Linus Walleij wrote:
>> On Tue, Oct 4, 2016 at 9:14 PM, Tejun Heo <tj@kernel.org> wrote:
>
>>> I get that bfq can be a good compromise on most desktop workloads and
>>> behave reasonably well for some server workloads with the slice
>>> expiration mechanism but it really isn't an IO resource partitioning
>>> mechanism.
>
>> Not just desktops, also Android phones.
>
>> So why not have BFQ as a separate scheduling policy upstream,
>> alongside CFQ, deadline and noop?
>
> Right.
>
>> We're already doing the per-usecase Kconfig thing for preemption.
>> But maybe somebody already hates that and want to get rid of it,
>> I don't know.
>
> Hannes also suggested going back to making BFQ a separate scheduler
> rather than replacing CFQ earlier, pointing out that it mitigates
> against the risks of changing CFQ substantially at this point (which
> seems to be the biggest issue here).
>
ISTR that the original argument for this approach essentially amounted
to: 'If it's so much better, why do we need both?'.
Such an argument is valid only if the new design is better in all
respects (which there isn't sufficient information to decide in this
case), or the negative aspects are worth the improvements (which is too
workload specific to decide for something like this).
next prev parent reply other threads:[~2016-10-06 11:57 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-03 21:20 [PATCH V3 00/11] block-throttle: add .high limit Shaohua Li
2016-10-03 21:20 ` [PATCH v3 01/11] block-throttle: prepare support multiple limits Shaohua Li
2016-10-03 21:20 ` [PATCH v3 02/11] block-throttle: add .high interface Shaohua Li
2016-10-03 21:20 ` [PATCH v3 03/11] block-throttle: configure bps/iops limit for cgroup in high limit Shaohua Li
2016-10-03 21:20 ` [PATCH v3 04/11] block-throttle: add upgrade logic for LIMIT_HIGH state Shaohua Li
2016-10-03 21:20 ` [PATCH v3 05/11] block-throttle: add downgrade logic Shaohua Li
2016-10-03 21:20 ` [PATCH v3 06/11] blk-throttle: make sure expire time isn't too big Shaohua Li
2016-10-03 21:20 ` [PATCH v3 07/11] blk-throttle: make throtl_slice tunable Shaohua Li
2016-10-03 21:20 ` [PATCH v3 08/11] blk-throttle: detect completed idle cgroup Shaohua Li
2016-10-03 21:20 ` [PATCH v3 09/11] block-throttle: make bandwidth change smooth Shaohua Li
2016-10-03 21:20 ` [PATCH v3 10/11] block-throttle: add a simple idle detection Shaohua Li
2016-10-03 21:20 ` [PATCH v3 11/11] blk-throttle: ignore idle cgroup limit Shaohua Li
2016-10-04 13:28 ` [PATCH V3 00/11] block-throttle: add .high limit Vivek Goyal
2016-10-04 15:56 ` Tejun Heo
2016-10-04 16:22 ` Paolo Valente
2016-10-04 16:27 ` Tejun Heo
2016-10-04 17:01 ` Paolo Valente
2016-10-04 17:28 ` Shaohua Li
2016-10-04 17:43 ` Paolo Valente
2016-10-04 18:28 ` Shaohua Li
2016-10-04 19:49 ` Paolo Valente
2016-10-04 18:54 ` Tejun Heo
2016-10-04 19:02 ` Paolo Valente
2016-10-04 19:14 ` Tejun Heo
2016-10-04 19:29 ` Paolo Valente
2016-10-04 20:27 ` Tejun Heo
2016-10-05 12:37 ` Paolo Valente
2016-10-05 13:12 ` Vivek Goyal
2016-10-05 14:04 ` Paolo Valente
2016-10-05 14:49 ` Tejun Heo
2016-10-05 18:30 ` Shaohua Li
2016-10-05 19:08 ` Shaohua Li
2016-10-05 19:57 ` Paolo Valente
2016-10-05 20:36 ` Shaohua Li
2016-10-06 7:22 ` Paolo Valente
2016-10-05 19:47 ` Paolo Valente
2016-10-05 20:07 ` Paolo Valente
2016-10-05 20:46 ` Shaohua Li
2016-10-06 7:58 ` Paolo Valente
2016-10-06 13:15 ` Paolo Valente
2016-10-06 17:49 ` Vivek Goyal
2016-10-06 18:01 ` Paolo Valente
2016-10-06 18:32 ` Vivek Goyal
2016-10-06 20:51 ` Paolo Valente
2016-10-06 19:44 ` Mark Brown
2016-10-06 19:57 ` Shaohua Li
2016-10-06 22:24 ` Paolo Valente
[not found] ` <CACsaVZ+AqSXHTRdpdrQQp6PuynEPeB-5YOyweWsenjvuKsD12w@mail.gmail.com>
2016-10-09 1:15 ` Fwd: " Kyle Sanderson
2016-10-14 16:40 ` Tejun Heo
2016-10-14 17:13 ` Paolo Valente
2016-10-14 18:35 ` Tejun Heo
2016-10-16 19:02 ` Paolo Valente
2016-10-18 5:15 ` Kyle Sanderson
2016-10-06 8:04 ` Linus Walleij
2016-10-06 11:03 ` Mark Brown
2016-10-06 11:57 ` Austin S. Hemmelgarn [this message]
2016-10-06 12:50 ` Paolo Valente
2016-10-06 13:52 ` Austin S. Hemmelgarn
2016-10-06 15:05 ` Paolo Valente
2016-10-06 15:10 ` Austin S. Hemmelgarn
2016-10-08 10:46 ` Heinz Diehl
2016-10-04 18:12 ` Vivek Goyal
2016-10-04 18:50 ` Tejun Heo
2016-10-04 18:56 ` Paolo Valente
2016-10-04 17:08 ` Shaohua Li
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