From mboxrd@z Thu Jan 1 00:00:00 1970 From: Waiman Long Subject: Re: [PATCH v6 2/2] cpuset: Add cpuset.sched_load_balance to v2 Date: Tue, 27 Mar 2018 10:23:33 -0400 Message-ID: References: <1521649309-26690-1-git-send-email-longman@redhat.com> <1521649309-26690-3-git-send-email-longman@redhat.com> <20180322084120.GE7231@localhost.localdomain> <20180323075952.GA4763@localhost.localdomain> <20180326124711.GE5942@localhost.localdomain> <20180327140259.GN1840639@devbig577.frc2.facebook.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8BIT Return-path: In-Reply-To: <20180327140259.GN1840639@devbig577.frc2.facebook.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Tejun Heo Cc: Juri Lelli , Li Zefan , Johannes Weiner , Peter Zijlstra , Ingo Molnar , cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, kernel-team@fb.com, pjt@google.com, luto@amacapital.net, efault@gmx.de, torvalds@linux-foundation.org, Roman Gushchin On 03/27/2018 10:02 AM, Tejun Heo wrote: > Hello, > > On Mon, Mar 26, 2018 at 04:28:49PM -0400, Waiman Long wrote: >> Maybe we can have a different root level flag, say, >> sched_partition_domain that is equivalent to !sched_load_balnace. >> However, I am still not sure if we should enforce that no task should be >> in the root cgroup when the flag is set. >> >> Tejun and Peter, what are your thoughts on this? > I haven't looked into the other issues too much but we for sure cannot > empty the root cgroup. > > Thanks. > Now, I have a different idea. How about we add a special root-only knob, say, "cpuset.cpus.isolated" that contains the list of CPUs that are still owned by root, but not participated in load balancing. All the tasks in the root are load-balanced among the remaining CPUs. A child can then be created that hold some or all the CPUs in the isolated set. It will then have a separate root domain if load balancing is on, or an isolated cpuset if load balancing is off. Will that idea work? Cheers, Longman