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] [day] [month] [year] [list]

Message-ID: <219817a9-773e-e1ea-9b85-7af15919bbc2@redhat.com>
Date:   Fri, 17 Aug 2018 21:03:28 -0400
From:   Waiman Long <longman@...hat.com>
To:     Tejun Heo <tj@...nel.org>
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

On 08/17/2018 11:59 AM, Tejun Heo wrote:
> Hello, Waiman.
>
> On Mon, Aug 13, 2018 at 01:56:15PM -0400, Waiman Long wrote:
>> The following restrictions are still imposed on a partition root wrt
>> allowable changes in cpuset.cpus:
>> 1) cpuset.cpus cannot be set to "". There must be at least 1 cpu there.
>> 2) Adding cpus that are not in parent's cpuset.cpus (as well as
>> cpuset.cpus.effective) or that will take all the parent's effective cpus
>> away is not allowed.
>>
>> So are these limitations acceptable?
>>
>> The easiest way to remove those restrictions is to forcefully turn off
>> the cpuset.sched.partition flag in the cpuset as well as any
>> sub-partitions when the user try to do that. With that change, there
>> will be no more new restriction on what you can do on cpuset.cpus.
> I think that'd be the right thing to do.  That's what we do with
> cpuset.cpus and cpuset.mems too.  If there's nothing available, we
> ignore the config and show the settings which are currently in effect.
>
> Thanks.
>
Thanks! I will send out an updated patch after the 4.19 merge window closes.

-Longman