From: Waiman Long <longman@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>, 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 v10 2/9] cpuset: Add new v2 cpuset.sched.domain_root flag
Date: Thu, 21 Jun 2018 15:58:06 +0800 [thread overview]
Message-ID: <b44b0748-9fec-6bb0-7665-435487e5d8b3@redhat.com> (raw)
In-Reply-To: <20180620142735.GM2494@hirez.programming.kicks-ass.net>
On 06/20/2018 10:27 PM, Peter Zijlstra wrote:
> On Mon, Jun 18, 2018 at 12:14:01PM +0800, Waiman Long wrote:
>> + cpuset.sched.domain_root
> Why are we calling this a domain_root and not a partition?
A partition can consist of several cgroups in a tree structure. That
flag should only be set at the root of a partition. I will change the
name to partition_root if you think this name is acceptable.
>
>> + A read-write single value file which exists on non-root
>> + cpuset-enabled cgroups. It is a binary value flag that accepts
>> + either "0" (off) or "1" (on). This flag is set by the parent
>> + and is not delegatable.
> You still haven't answered:
> ,
> https://lkml.kernel.org/r/20180531094943.GG12180@hirez.programming.kicks-ass.net
>
> the question stands.
I am sorry to miss your question. Turning on domain_root will affects
the cpu mapping in the parent. That is why it cannot be set by the child
as a child is not supposed to be able to affect the parent.
As for the inconsistency between the real root and the container root,
this is true for almost all the controllers. So it is a generic problem.
One possible solution is to create a kind a pseudo root cgroup for the
container that looks and feels like a real root. But is there really a
need to do that?
Cheers,
Longman
next prev parent reply other threads:[~2018-06-21 7:58 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-18 4:13 [PATCH v10 0/9] cpuset: Enable cpuset controller in default hierarchy Waiman Long
2018-06-18 4:14 ` [PATCH v10 1/9] " Waiman Long
2018-06-18 4:14 ` [PATCH v10 2/9] cpuset: Add new v2 cpuset.sched.domain_root flag Waiman Long
2018-06-20 14:27 ` Peter Zijlstra
2018-06-21 7:58 ` Waiman Long [this message]
2018-06-21 8:05 ` Waiman Long
2018-06-21 9:20 ` Peter Zijlstra
2018-06-22 3:00 ` Waiman Long
2018-07-02 16:32 ` Tejun Heo
2018-06-21 9:27 ` Peter Zijlstra
2018-06-22 2:48 ` Waiman Long
2018-06-18 4:14 ` [PATCH v10 3/9] cpuset: Simulate auto-off of sched.domain_root at cgroup removal Waiman Long
2018-06-20 14:11 ` Peter Zijlstra
2018-06-21 8:22 ` Waiman Long
2018-06-18 4:14 ` [PATCH v10 4/9] cpuset: Allow changes to cpus in a domain root Waiman Long
2018-06-18 4:14 ` [PATCH v10 5/9] cpuset: Make sure that domain roots work properly with CPU hotplug Waiman Long
2018-06-20 14:15 ` Peter Zijlstra
2018-06-21 3:09 ` Waiman Long
2018-06-18 4:14 ` [PATCH v10 6/9] cpuset: Make generate_sched_domains() recognize isolated_cpus Waiman Long
2018-06-18 14:44 ` Waiman Long
2018-06-18 14:58 ` Juri Lelli
2018-06-18 4:14 ` [PATCH v10 6/9] cpuset: Make generate_sched_domains() recognize reserved_cpus Waiman Long
2018-06-20 14:17 ` Peter Zijlstra
2018-06-21 8:14 ` Waiman Long
2018-06-18 4:14 ` [PATCH v10 7/9] cpuset: Expose cpus.effective and mems.effective on cgroup v2 root Waiman Long
2018-06-18 4:14 ` [PATCH v10 8/9] cpuset: Don't rebuild sched domains if cpu changes in non-domain root Waiman Long
2018-06-18 4:14 ` [PATCH v10 9/9] cpuset: Allow reporting of sched domain generation info Waiman Long
2018-06-20 14:20 ` Peter Zijlstra
2018-06-18 14:20 ` [PATCH v10 0/9] cpuset: Enable cpuset controller in default hierarchy Juri Lelli
2018-06-18 15:07 ` Waiman Long
2018-06-19 9:52 ` Juri Lelli
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=b44b0748-9fec-6bb0-7665-435487e5d8b3@redhat.com \
--to=longman@redhat.com \
--cc=cgroups@vger.kernel.org \
--cc=efault@gmx.de \
--cc=guro@fb.com \
--cc=hannes@cmpxchg.org \
--cc=juri.lelli@redhat.com \
--cc=kernel-team@fb.com \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=lizefan@huawei.com \
--cc=luto@amacapital.net \
--cc=mingo@redhat.com \
--cc=patrick.bellasi@arm.com \
--cc=peterz@infradead.org \
--cc=pjt@google.com \
--cc=tj@kernel.org \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®