linux-kernel - Re: [PATCH v11 7/9] cpuset: Expose cpus.effective and mems.effective on cgroup v2 root

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20180720174100.GC1934745@devbig577.frc2.facebook.com>
Date:   Fri, 20 Jul 2018 10:41:00 -0700
From:   Tejun Heo <tj@...nel.org>
To:     Waiman Long <longman@...hat.com>
Cc:     Peter Zijlstra <peterz@...radead.org>,
        Li Zefan <lizefan@...wei.com>,
        Johannes Weiner <hannes@...xchg.org>,
        Ingo Molnar <mingo@...hat.com>, cgroups@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-doc@...r.kernel.org,
        kernel-team@...com, pjt@...gle.com, luto@...capital.net,
        Mike Galbraith <efault@....de>, torvalds@...ux-foundation.org,
        Roman Gushchin <guro@...com>,
        Juri Lelli <juri.lelli@...hat.com>,
        Patrick Bellasi <patrick.bellasi@....com>
Subject: Re: [PATCH v11 7/9] cpuset: Expose cpus.effective and mems.effective
 on cgroup v2 root

Hello,

On Fri, Jul 20, 2018 at 01:09:23PM -0400, Waiman Long wrote:
> On 07/20/2018 12:37 PM, Peter Zijlstra wrote:
> > On Fri, Jul 20, 2018 at 12:19:29PM -0400, Waiman Long wrote:
> >> I am not against the idea of making it hierarchical eventually. I am
> >> just hoping to get thing going by merging the patchset in its current
> >> form and then we can make it hierarchical in a followup patch.
> > Where's the rush? Why can't we do this right in one go?
> 
> For me, the rush comes from RHEL8 as it is a goal to have a fully
> functioning cgroup v2 in that release.
> 
> I also believe that most of the use cases of partition can be satisfied
> with partitions at the first level children. Getting hierarchical
> partition right may drag on for half a year, maybe, giving our history
> with cpu v2 controller. No matter what we do to enable hierarchical
> partition in the future, the current model of using a partition flag is
> intuitive enough that it won't be changed at least for the first level
> children.

I'm fully with Waiman here.  There are people wanting to use it and
the part most people isn't controversial at all.  I don't see what'd
be gained by further delaying the whole thing.  If the first level
partition thing isn't acceptable to everyone, we can even strip down
further.  We can get .cpus and .mems merged first, which is what most
people want anyway.

Thanks.

-- 
tejun