From: Tejun Heo <tj@kernel.org>
To: "Michal Koutný" <mkoutny@suse.com>
Cc: hannes@cmpxchg.org, clm@fb.com, dennisz@fb.com, newella@fb.com,
lizefan@huawei.com, axboe@kernel.dk, josef@toxicpanda.com,
Josef Bacik <jbacik@fb.com>,
kernel-team@fb.com, Rik van Riel <riel@surriel.com>,
cgroups@vger.kernel.org, linux-block@vger.kernel.org,
linux-kernel@vger.kernel.org,
Paolo Valente <paolo.valente@linaro.org>
Subject: Re: [PATCH 08/10] blkcg: implement blk-iocost
Date: Tue, 10 Sep 2019 09:08:55 -0700 [thread overview]
Message-ID: <20190910160855.GS2263813@devbig004.ftw2.facebook.com> (raw)
In-Reply-To: <20190910125513.GA6399@blackbody.suse.cz>
Hello, Michal.
On Tue, Sep 10, 2019 at 02:55:14PM +0200, Michal Koutný wrote:
> This adds the generic io.weight attribute. How will this compose with
> the weight from IO schedulers? (AFAIK, only BFQ allows proportional
> control as of now. +CC Paolo.)
The two being enabled at the same time doesn't make sense, so we can
just switch over to bfq when bfq is selected as the iosched. I asked
what Paolo wanted to do in terms of interface a couple times now but
didn't get an answer and he posted a patch which makes the two
controllers conflict, so.... Paolo, so it looks like you want to
rename all bfq files to drop the bfq prefix, right? I can implement
the switching if so.
> I see this attributes are effectively per-cgroup per-device. Apparently,
> one device should have only one weight across hierarchy. Would it make
> sense to have io.bfq.weight and io.cost.weight with disjunctive devices?
It never makes sense to have both enabled, so I don't think that
interface makes sense.
> > + .name = "cost.qos",
> > + .flags = CFTYPE_ONLY_ON_ROOT,
> > [...]
> > + .name = "cost.model",
> > + .flags = CFTYPE_ONLY_ON_ROOT,
> I'm concerned that these aren't true cgroup attributes. The root cgroup
> would act as container for global configuration options. Wouldn't these
> values better fit as (configurable) attributes of the respective
> devices?
Initially, I put them under block device sysfs but it was too clumsy
with different config file formats and all. I think it's better to
have global controller configs at the root cgroup.
> Secondly, how is CFTYPE_ONLY_ON_ROOT supposed to be presented in cgroup
> namespaces?
Not at all. These are system-wide configs. cgroup namespaces
shouldn't have anything which aren't in non-root cgroups.
Thanks.
--
tejun
next prev parent reply other threads:[~2019-09-10 16:09 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-28 22:05 [PATCHSET v3 block/for-linus] IO cost model based work-conserving porportional controller Tejun Heo
2019-08-28 22:05 ` [PATCH 01/10] blkcg: pass @q and @blkcg into blkcg_pol_alloc_pd_fn() Tejun Heo
2019-08-28 22:05 ` [PATCH 02/10] blkcg: make ->cpd_init_fn() optional Tejun Heo
2019-08-28 22:05 ` [PATCH 03/10] blkcg: separate blkcg_conf_get_disk() out of blkg_conf_prep() Tejun Heo
2019-08-28 22:05 ` [PATCH 04/10] block/rq_qos: add rq_qos_merge() Tejun Heo
2019-08-28 22:05 ` [PATCH 05/10] block/rq_qos: implement rq_qos_ops->queue_depth_changed() Tejun Heo
2019-08-28 22:05 ` [PATCH 06/10] blkcg: s/RQ_QOS_CGROUP/RQ_QOS_LATENCY/ Tejun Heo
2019-08-28 22:05 ` [PATCH 07/10] blk-mq: add optional request->alloc_time_ns Tejun Heo
2019-08-28 22:05 ` [PATCH 08/10] blkcg: implement blk-iocost Tejun Heo
2019-08-29 15:53 ` [PATCH] blkcg: fix missing free on error path of blk_iocost_init() Tejun Heo
2019-09-10 12:55 ` [PATCH 08/10] blkcg: implement blk-iocost Michal Koutný
2019-09-10 16:08 ` Tejun Heo [this message]
2019-09-11 8:18 ` Paolo Valente
2019-09-11 14:16 ` Tejun Heo
2019-09-11 15:54 ` Tejun Heo
2019-09-11 16:44 ` Paolo Valente
2019-10-03 14:51 ` Michal Koutný
2019-10-03 16:45 ` Tejun Heo
2019-10-09 15:36 ` Michal Koutný
2019-10-14 15:36 ` Tejun Heo
2019-11-01 16:15 ` Michal Koutný
2019-11-01 16:56 ` Paolo Valente
2019-08-28 22:05 ` [PATCH 09/10] blkcg: add tools/cgroup/iocost_monitor.py Tejun Heo
2019-08-28 22:06 ` [PATCH 10/10] blkcg: add tools/cgroup/iocost_coef_gen.py Tejun Heo
2019-08-29 3:29 ` [PATCHSET v3 block/for-linus] IO cost model based work-conserving porportional controller Jens Axboe
[not found] ` <20190829082248.6464-1-hdanton@sina.com>
2019-08-29 15:43 ` [PATCH 07/10] blk-mq: add optional request->alloc_time_ns Tejun Heo
[not found] ` <20190829133928.16192-1-hdanton@sina.com>
2019-08-29 15:46 ` [PATCH 08/10] blkcg: implement blk-iocost Tejun Heo
2019-08-29 15:54 ` [PATCHSET v3 block/for-linus] IO cost model based work-conserving porportional controller Paolo Valente
2019-08-29 15:56 ` Tejun Heo
-- strict thread matches above, loose matches on Subject: below --
2019-07-10 20:51 [PATCHSET v2 " Tejun Heo
2019-07-10 20:51 ` [PATCH 08/10] blkcg: implement blk-iocost Tejun Heo
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