Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752656AbdLESyQ (ORCPT ); Tue, 5 Dec 2017 13:54:16 -0500 Received: from mail-wm0-f67.google.com ([74.125.82.67]:40419 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752312AbdLESyN (ORCPT ); Tue, 5 Dec 2017 13:54:13 -0500 X-Google-Smtp-Source: AGs4zMYzVOq64ZOpV0P9OwelKDNqGKUFMstnlhPeutS8qv5aeeUG+evJarzWtTxHK/6hDargVfmvcbvMPQI8uq33RLI= MIME-Version: 1.0 Reply-To: mtk.manpages@gmail.com In-Reply-To: <20171205182901.GW2421075@devbig577.frc2.facebook.com> References: <20171204214710.GM2421075@devbig577.frc2.facebook.com> <8fa060d2-07c7-7306-3d93-781c919f24eb@gmail.com> <20171205160049.GT2421075@devbig577.frc2.facebook.com> <20171205171357.GU2421075@devbig577.frc2.facebook.com> <20171205182901.GW2421075@devbig577.frc2.facebook.com> From: "Michael Kerrisk (man-pages)" Date: Tue, 5 Dec 2017 19:53:51 +0100 Message-ID: Subject: Re: [PATCH v2 cgroup/for-4.15-fixes] cgroup: add warning about RT not being supported on cgroup2 To: Tejun Heo Cc: lkml , Lennart Poettering Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1426 Lines: 41 On 5 December 2017 at 19:29, Tejun Heo wrote: > From f0a821260f24ea9378ed0e0c149e3bbc1a1bd008 Mon Sep 17 00:00:00 2001 > From: Tejun Heo > Date: Tue, 5 Dec 2017 09:10:17 -0800 > > We haven't yet figured out what to do with RT threads on cgroup2. > Document the limitation. > > v2: Included the warning about system management software behavior as > suggested by Michael. > > Signed-off-by: Tejun Heo > Reported-by: "Michael Kerrisk (man-pages)" > --- > Documentation/cgroup-v2.txt | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/Documentation/cgroup-v2.txt b/Documentation/cgroup-v2.txt > index 779211f..c5e3c21 100644 > --- a/Documentation/cgroup-v2.txt > +++ b/Documentation/cgroup-v2.txt > @@ -898,6 +898,13 @@ controller implements weight and absolute bandwidth limit models for > normal scheduling policy and absolute bandwidth allocation model for > realtime scheduling policy. > > +WARNING: cgroup2 doesn't yet support control of realtime processes and > +the cpu controller can only be enabled when all RT processes are in > +the root cgroup. Be aware that that system management software may Sorry, there was a fault in my text: s/that that/that/ Thanks, Michael -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/