From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756402AbdETCLl (ORCPT ); Fri, 19 May 2017 22:11:41 -0400 Received: from mout.gmx.net ([212.227.15.15]:49197 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754590AbdETCLi (ORCPT ); Fri, 19 May 2017 22:11:38 -0400 Message-ID: <1495246207.7442.2.camel@gmx.de> Subject: Re: [RFC PATCH v2 12/17] cgroup: Remove cgroup v2 no internal process constraint From: Mike Galbraith To: Tejun Heo , Waiman Long Cc: Li Zefan , Johannes Weiner , Peter Zijlstra , Ingo Molnar , cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, kernel-team@fb.com, pjt@google.com, luto@amacapital.net Date: Sat, 20 May 2017 04:10:07 +0200 In-Reply-To: <20170519203824.GC15279@wtj.duckdns.org> References: <1494855256-12558-1-git-send-email-longman@redhat.com> <1494855256-12558-13-git-send-email-longman@redhat.com> <20170519203824.GC15279@wtj.duckdns.org> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.20.5 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Provags-ID: V03:K0:1eg9PEUstD1jTMUM8QApciWEtGxLS0V9Apx8oiQ0U94QeimzU+2 fgEMqole+3J/8c0xjUr50/toKY5PuaMkKYoAZv0nWyt1YadP1fh4nZ24SCLU2G4ipY23KbK Nxmy0I/or1IwAcyxHx8HQyADfPdNrL7pZwMSjTc7iS6deNXhVO8HgeVq915CXIfTxsewwNE BAyNq97kA/WAfz3FoeNpQ== X-UI-Out-Filterresults: notjunk:1;V01:K0:uj+BTt+pEhI=:+Qbqak7+sDBd9BxNbybVnN O5nG8psR9sMoFk79vdqElNe5nC92g1ZdV6PsSJPlm/zHJSW0VF5ui5onLdCcni7JDENrJAgHy UA+qVyWNhqZHUMTtgcYWQQayZ1gALe8e1Mmqih5FvpKa0HldQ6oHEIH0WZ0PpcD6CpwuRisD/ ihLBCwYseMkWIjb5ucGxv4bE8PUFTVVKYeUDrVFd2p4aJPxEsutyzrZDU76LNEcSOWHpRt2ZN YIulEBiNuIInNKysXNJtfdObJyoIdbWV/kmu2kmllFDrFz8AAybpQ279J8EPlQ5ZXcYLo7THm T2mcvjWHlRUpWHe9sL3rvBEVAeZl2kziQO99cNu1Yr44Ot0zYgbt3GdEGXUesDve3+H5vVIPs lUSpV9Q/7MCZ2V3awgAuZkq8arlkb8hcdA3l0yu7PRvd86YBYJblI6/LVKI/Etj2CiKzuPpAy +ZAatKSmK5960qHXr5WSaqRyfO0U5YTeVjfID6XhRmkaId7C45W0d9JV+CbtlZH8cKYBuHHy2 gLyHV4f15nkEkOAhQvE3xdwMuqWPk3uJyWsJGBW9QWoaiw4g/zvbbXCaRKvIJiPgEdOyRs0Ne irkyGoY2VftqVXQLAw3umLsUwh5IerJJzDbzwQjUzz9VByXAU8m3MK7mPJvNrS+IN4b9j+aiI HOhbGWPTHpjdlrNRu+mf1EUnWwJGk8FBwep5rq2tCxjD64ntQJq6tz+stFcN5dxUps/B8rIb8 uModsyJUijckVhPkK8QpdSHIH4OHEuW37sXRwX3F2tcJB5B4hXJAAtm7tyPn3Y9ONfTcAozUx wtPgYcm Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2017-05-19 at 16:38 -0400, Tejun Heo wrote: > Hello, Waiman. > > On Mon, May 15, 2017 at 09:34:11AM -0400, Waiman Long wrote: > > The rationale behind the cgroup v2 no internal process constraint is > > to avoid resouorce competition between internal processes and child > > cgroups. However, not all controllers have problem with internal > > process competiton. Enforcing this rule may lead to unnatural process > > hierarchy and unneeded levels for those controllers. > > This isn't necessarily something we can determine by looking at the > current state of controllers. It's true that some controllers - pid > and perf - inherently only care about membership of each task but at > the same time neither really suffers from the constraint either. CPU > which is the problematic one here... (+ cpuacct + cpuset)