From: Raghavendra KT <raghavendra.kt-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
To: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org,
Linux Kernel Mailing List
<linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
Vivek Goyal <vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Subject: Re: [PATCHSET cgroup/for-3.15] cgroup: implement unified hierarchy
Date: Wed, 30 Apr 2014 16:27:51 +0530 [thread overview]
Message-ID: <CAC4Lta0qd2vW4ENSOpzK+0i06MorzfmsZZZuW9xUtpZ_gWA9gA@mail.gmail.com> (raw)
In-Reply-To: <20140414175236.GB15249-Gd/HAXX7CRxy/B6EtB590w@public.gmane.org>
On Mon, Apr 14, 2014 at 11:22 PM, Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> wrote:
>> How does this work for root's tasks now? Given that task can only be
>> in leaf cgroups, that means tasks can't be in / cgroup (If one wants
>> to create some cgroups). Does that mean / will be empty and init system
>> need to setup things right.
>
> Root is exempt from the restriction. Root has always been special
> anyway.
>
(I do not wish to Hijack this thread, but found a relevant context
here to initiate discussion. But would discuss in a separate thread
once I get a positive go on the topic)
Hi Tejun,
For some controllers like cpuset, when we have exclusive_cpu is set,
what about having a knob in the cpuset controller
to move the task to non-root (when option is set).
Because all the way along, though we have freedom to make the cpusets
exclusive and move tasks (say VMs) into them,
making sure they do not interfere with each other, we can not prevent
the other tasks spawned in a system eating into cpus of
exclusive cpuset since they go to root automatically.
Do you think having a knob, to make sure new tasks spawned go to say a
default directory under root makes sense?
I understand that we could easily have a userspace script which could
achieve intended goal, but kernel solution
would really make the exclusive cpusets have exclusive access to cpus
it should have.
(I also have a POC implemented for pre-unified hierarchy tree and
understand some bit of complications involved in that and
understand that we should not have complex policies in kernel for e.g.
filtering tasks based on patterns etc..).
WARNING: multiple messages have this Message-ID (diff)
From: Raghavendra KT <raghavendra.kt@linux.vnet.ibm.com>
To: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>,
lizefan@huawei.com, containers@lists.linux-foundation.org,
cgroups@vger.kernel.org,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCHSET cgroup/for-3.15] cgroup: implement unified hierarchy
Date: Wed, 30 Apr 2014 16:27:51 +0530 [thread overview]
Message-ID: <CAC4Lta0qd2vW4ENSOpzK+0i06MorzfmsZZZuW9xUtpZ_gWA9gA@mail.gmail.com> (raw)
In-Reply-To: <20140414175236.GB15249@htj.dyndns.org>
On Mon, Apr 14, 2014 at 11:22 PM, Tejun Heo <tj@kernel.org> wrote:
>> How does this work for root's tasks now? Given that task can only be
>> in leaf cgroups, that means tasks can't be in / cgroup (If one wants
>> to create some cgroups). Does that mean / will be empty and init system
>> need to setup things right.
>
> Root is exempt from the restriction. Root has always been special
> anyway.
>
(I do not wish to Hijack this thread, but found a relevant context
here to initiate discussion. But would discuss in a separate thread
once I get a positive go on the topic)
Hi Tejun,
For some controllers like cpuset, when we have exclusive_cpu is set,
what about having a knob in the cpuset controller
to move the task to non-root (when option is set).
Because all the way along, though we have freedom to make the cpusets
exclusive and move tasks (say VMs) into them,
making sure they do not interfere with each other, we can not prevent
the other tasks spawned in a system eating into cpus of
exclusive cpuset since they go to root automatically.
Do you think having a knob, to make sure new tasks spawned go to say a
default directory under root makes sense?
I understand that we could easily have a userspace script which could
achieve intended goal, but kernel solution
would really make the exclusive cpusets have exclusive access to cpus
it should have.
(I also have a POC implemented for pre-unified hierarchy tree and
understand some bit of complications involved in that and
understand that we should not have complex policies in kernel for e.g.
filtering tasks based on patterns etc..).
next prev parent reply other threads:[~2014-04-30 10:57 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-28 2:40 [PATCHSET cgroup/for-3.15] cgroup: implement unified hierarchy Tejun Heo
2014-03-28 2:40 ` Tejun Heo
2014-03-28 2:40 ` [PATCH 04/12] cgroup: make css_next_child() skip missing csses Tejun Heo
2014-03-28 2:40 ` [PATCH 06/12] cgroup: teach css_task_iter about effective csses Tejun Heo
2014-03-28 2:40 ` [PATCH 10/12] cgroup: update subsystem rebind restrictions Tejun Heo
2014-03-28 2:41 ` [PATCH 11/12] cgroup: prepare migration path for unified hierarchy Tejun Heo
2014-03-28 2:41 ` [PATCH 12/12] cgroup: implement dynamic subtree controller enable/disable on the default hierarchy Tejun Heo
2014-03-28 2:41 ` Tejun Heo
[not found] ` <1395974461-12735-1-git-send-email-tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
2014-03-28 2:40 ` [PATCH 01/12] cgroup: update cgroup->subsys_mask to ->child_subsys_mask and restore cgroup_root->subsys_mask Tejun Heo
2014-03-28 2:40 ` Tejun Heo
2014-03-28 2:40 ` [PATCH 02/12] cgroup: introduce effective cgroup_subsys_state Tejun Heo
2014-03-28 2:40 ` Tejun Heo
2014-03-28 2:40 ` [PATCH 03/12] cgroup: implement cgroup->e_csets[] Tejun Heo
2014-03-28 2:40 ` Tejun Heo
2014-03-28 2:40 ` [PATCH 04/12] cgroup: make css_next_child() skip missing csses Tejun Heo
2014-03-28 2:40 ` [PATCH 05/12] cgroup: reorganize css_task_iter Tejun Heo
2014-03-28 2:40 ` Tejun Heo
2014-03-28 2:40 ` [PATCH 06/12] cgroup: teach css_task_iter about effective csses Tejun Heo
2014-03-28 2:40 ` [PATCH 07/12] cgroup: cgroup->subsys[] should be cleared after the css is offlined Tejun Heo
2014-03-28 2:40 ` Tejun Heo
2014-03-28 2:40 ` [PATCH 08/12] cgroup: allow cgroup creation and suppress automatic css creation in the unified hierarchy Tejun Heo
2014-03-28 2:40 ` Tejun Heo
2014-03-28 2:40 ` [PATCH 09/12] cgroup: add css_set->dfl_cgrp Tejun Heo
2014-03-28 2:40 ` Tejun Heo
2014-03-28 2:40 ` [PATCH 10/12] cgroup: update subsystem rebind restrictions Tejun Heo
2014-03-28 2:41 ` [PATCH 11/12] cgroup: prepare migration path for unified hierarchy Tejun Heo
2014-03-28 2:41 ` [PATCH 12/12] cgroup: implement dynamic subtree controller enable/disable on the default hierarchy Tejun Heo
2014-04-14 15:45 ` [PATCHSET cgroup/for-3.15] cgroup: implement unified hierarchy Vivek Goyal
2014-04-14 15:45 ` Vivek Goyal
[not found] ` <20140414154556.GA9552-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2014-04-14 17:52 ` Tejun Heo
2014-04-14 17:52 ` Tejun Heo
[not found] ` <20140414175236.GB15249-Gd/HAXX7CRxy/B6EtB590w@public.gmane.org>
2014-04-14 18:14 ` Vivek Goyal
2014-04-14 18:14 ` Vivek Goyal
[not found] ` <20140414181421.GC9552-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2014-04-14 19:21 ` Tejun Heo
2014-04-14 19:21 ` Tejun Heo
[not found] ` <20140414192139.GB16835-Gd/HAXX7CRxy/B6EtB590w@public.gmane.org>
2014-04-15 2:58 ` Li Zefan
2014-04-15 2:58 ` Li Zefan
[not found] ` <534CA050.8060709-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
2014-04-15 4:57 ` Tejun Heo
2014-04-15 4:57 ` Tejun Heo
2014-04-30 10:57 ` Raghavendra KT [this message]
2014-04-30 10:57 ` Raghavendra KT
[not found] ` <CAC4Lta0qd2vW4ENSOpzK+0i06MorzfmsZZZuW9xUtpZ_gWA9gA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-05-02 15:12 ` Tejun Heo
2014-05-02 15:12 ` Tejun Heo
2014-05-05 16:37 ` Raghavendra KT
2014-05-05 16:37 ` Raghavendra KT
2014-04-14 21:31 ` Tejun Heo
2014-04-14 21:31 ` Tejun Heo
2014-04-15 22:05 ` [PATCH 0.5/12] cgroup: cgroup_apply_cftypes() shouldn't skip the default hierarhcy Tejun Heo
2014-04-15 22:05 ` Tejun Heo
2014-04-15 22:05 ` Tejun Heo
[not found] ` <20140415220504.GA13099-9pTldWuhBndy/B6EtB590w@public.gmane.org>
2014-04-15 22:05 ` Tejun Heo
2014-04-15 22:05 ` Tejun Heo
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