From mboxrd@z Thu Jan 1 00:00:00 1970 From: Waiman Long Subject: Re: [PATCH v10 2/9] cpuset: Add new v2 cpuset.sched.domain_root flag Date: Thu, 21 Jun 2018 16:05:10 +0800 Message-ID: <89436f95-47d7-32d9-d466-ac7d4c58f25b@redhat.com> References: <1529295249-5207-1-git-send-email-longman@redhat.com> <1529295249-5207-3-git-send-email-longman@redhat.com> <20180620142735.GM2494@hirez.programming.kicks-ass.net> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Peter Zijlstra Cc: Tejun Heo , Li Zefan , Johannes Weiner , 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, Mike Galbraith , torvalds@linux-foundation.org, Roman Gushchin , Juri Lelli , Patrick Bellasi On 06/21/2018 03:58 PM, Waiman Long wrote: > 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. After thinking a bit more about it, you are right that I should not use the term "not delegatable" here. I will rephrase in the next version. Cheers, Longman