From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751256AbdFAVMr convert rfc822-to-8bit (ORCPT ); Thu, 1 Jun 2017 17:12:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42560 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751105AbdFAVMp (ORCPT ); Thu, 1 Jun 2017 17:12:45 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com C58A780470 Authentication-Results: ext-mx04.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx04.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=longman@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com C58A780470 Subject: Re: [RFC PATCH v2 11/17] cgroup: Implement new thread mode semantics To: Tejun Heo References: <20170524203616.GO24798@htj.duckdns.org> <9b147a7e-fec3-3b78-7587-3890efcd42f2@redhat.com> <20170524212745.GP24798@htj.duckdns.org> <20170601145042.GA3494@htj.duckdns.org> <20170601151045.xhsv7jauejjis3mi@hirez.programming.kicks-ass.net> <20170601184740.GC3494@htj.duckdns.org> <20170601203815.GA13390@htj.duckdns.org> <20170601205203.GB13390@htj.duckdns.org> Cc: Peter Zijlstra , Li Zefan , Johannes Weiner , 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, efault@gmx.de From: Waiman Long Organization: Red Hat Message-ID: <1e775dcf-61b2-29d5-a214-350dc81c632b@redhat.com> Date: Thu, 1 Jun 2017 17:12:42 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <20170601205203.GB13390@htj.duckdns.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8BIT X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Thu, 01 Jun 2017 21:12:45 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/01/2017 04:52 PM, Tejun Heo wrote: > Hello, > > On Thu, Jun 01, 2017 at 04:48:48PM -0400, Waiman Long wrote: >> I think we are on agreement here. I should we should just document how >> userland can work around the internal process competition issue by >> setting up the cgroup hierarchy properly. Then we can remove the no >> internal process constraint. > Heh, we agree on the immediate solution but not the final direction. > This requirement affects how controllers implement resource control in > significant ways. It is a restriction which can be worked around in > userland relatively easily. I'd much prefer to keep the invariant > intact. > > Thanks. > Are you referring to keeping the no internal process restriction and document how to work around that instead? I would like to hear what workarounds are currently being used. Anyway, you currently allow internal process in thread mode, but not in non-thread mode. I would prefer no such restriction in both thread and non-thread mode. Cheers, Longman