From: Tejun Heo <tj@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Waiman Long <longman@redhat.com>, Li Zefan <lizefan@huawei.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Ingo Molnar <mingo@redhat.com>,
cgroups@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-doc@vger.kernel.org, kernel-team@fb.com, pjt@google.com,
luto@amacapital.net, Mike Galbraith <efault@gmx.de>,
torvalds@linux-foundation.org, Roman Gushchin <guro@fb.com>,
Juri Lelli <juri.lelli@redhat.com>,
Patrick Bellasi <patrick.bellasi@arm.com>
Subject: Re: [PATCH v11 7/9] cpuset: Expose cpus.effective and mems.effective on cgroup v2 root
Date: Fri, 20 Jul 2018 05:04:16 -0700 [thread overview]
Message-ID: <20180720120416.GA1934745@devbig577.frc2.facebook.com> (raw)
In-Reply-To: <20180720114549.GY72677@devbig577.frc2.facebook.com>
Hello,
On Fri, Jul 20, 2018 at 04:45:49AM -0700, Tejun Heo wrote:
> > > 2. take away any given cpu from ist subtree.
> >
> > I really hate this obsession of yours and doubly so for partitions. But
> > why would this currently not be allowed?
>
> Well, sorry that you hate it. It's a fundamental architectural
> constraint. If it can't satisfy that, it should't be in cgroup.
Just in case it wasn't clear from previous the exchanges, basic
architecture designs like this are what makes things like delegation
actually useful across all controllers. If we allow a descendant in
the hierarchy to restrict waht its ancestors can do, it becomes really
painful operationally.
For now, I'd suggest just doing it at the first child level and move
on unless there are clear use cases where nested partitions are
useful, which I find unlikely given the nature of the operation -
partitions don't really have anything to do with one another.
Thanks.
--
tejun
next prev parent reply other threads:[~2018-07-20 12:04 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-24 7:30 [PATCH v11 0/9] cpuset: Enable cpuset controller in default hierarchy Waiman Long
2018-06-24 7:30 ` [PATCH v11 1/9] " Waiman Long
2018-06-24 7:30 ` [PATCH v11 2/9] cpuset: Add new v2 cpuset.sched.partition flag Waiman Long
2018-06-24 7:30 ` [PATCH v11 3/9] cpuset: Simulate auto-off of sched.partition at cgroup removal Waiman Long
2018-06-24 7:30 ` [PATCH v11 4/9] cpuset: Allow changes to cpus in a partition root Waiman Long
2018-06-24 7:30 ` [PATCH v11 5/9] cpuset: Make sure that partition flag work properly with CPU hotplug Waiman Long
2018-06-24 7:30 ` [PATCH v11 6/9] cpuset: Make generate_sched_domains() recognize reserved_cpus Waiman Long
2018-06-24 7:30 ` [PATCH v11 7/9] cpuset: Expose cpus.effective and mems.effective on cgroup v2 root Waiman Long
2018-07-02 16:53 ` Tejun Heo
2018-07-03 0:41 ` Waiman Long
2018-07-03 15:58 ` Tejun Heo
2018-07-06 20:32 ` Waiman Long
2018-07-10 15:23 ` Waiman Long
2018-07-18 15:21 ` Waiman Long
2018-07-18 15:31 ` Tejun Heo
2018-07-18 21:12 ` Waiman Long
2018-07-19 13:52 ` Peter Zijlstra
2018-07-19 14:04 ` Waiman Long
2018-07-19 15:30 ` Tejun Heo
2018-07-19 15:52 ` Waiman Long
2018-07-19 16:52 ` Tejun Heo
2018-07-19 17:22 ` Waiman Long
2018-07-19 17:25 ` Tejun Heo
2018-07-19 17:38 ` Waiman Long
2018-07-20 11:32 ` Peter Zijlstra
2018-07-20 11:31 ` Peter Zijlstra
2018-07-20 11:45 ` Tejun Heo
2018-07-20 12:04 ` Tejun Heo [this message]
2018-07-20 15:44 ` Peter Zijlstra
2018-07-20 15:56 ` Tejun Heo
2018-07-20 16:19 ` Waiman Long
2018-07-20 16:37 ` Peter Zijlstra
2018-07-20 17:09 ` Waiman Long
2018-07-20 17:41 ` Tejun Heo
2018-08-13 17:56 ` Waiman Long
2018-08-17 15:59 ` Tejun Heo
2018-08-18 1:03 ` Waiman Long
2018-07-27 21:21 ` Waiman Long
2018-07-20 16:25 ` Peter Zijlstra
2018-07-20 15:57 ` Waiman Long
2018-07-20 11:29 ` Peter Zijlstra
2018-06-24 7:30 ` [PATCH v11 8/9] cpuset: Don't rebuild sched domains if cpu changes in non-partition root Waiman Long
2018-06-24 7:30 ` [PATCH v11 9/9] cpuset: Allow reporting of sched domain generation info Waiman Long
2018-07-19 13:54 ` Peter Zijlstra
2018-07-19 13:56 ` Waiman Long
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