Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752120AbbB1Qn7 (ORCPT ); Sat, 28 Feb 2015 11:43:59 -0500 Received: from mail-qc0-f182.google.com ([209.85.216.182]:40435 "EHLO mail-qc0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750986AbbB1Qn5 (ORCPT ); Sat, 28 Feb 2015 11:43:57 -0500 Date: Sat, 28 Feb 2015 11:43:53 -0500 From: Tejun Heo To: Tim Hockin Cc: Frederic Weisbecker , Austin S Hemmelgarn , lizefan@huawei.com, richard@nod.at, mingo@redhat.com, Aleksa Sarai , cgroups@vger.kernel.org, peterz@infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH RFC 0/2] add nproc cgroup subsystem Message-ID: <20150228164353.GR3964@htj.duckdns.org> References: <1424660891-12719-1-git-send-email-cyphar@cyphar.com> <20150227114940.GB3964@htj.duckdns.org> <54F09E62.8000007@gmail.com> <20150227170640.GK3964@htj.duckdns.org> <54F0BC51.4050506@gmail.com> <20150228115926.GA1005@htj.duckdns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1119 Lines: 28 Hello, Tim. On Sat, Feb 28, 2015 at 08:38:07AM -0800, Tim Hockin wrote: > I know there is not much concern for legacy-system problems, but it is > worth adding this case - there are systems that limit PIDs for other > reasons, eg broken infrastructure that assumes PIDs fit in a short int, > hypothetically. Given such a system, PIDs become precious and limiting > them per job is important. > > My main point being that there are less obvious considerations in play than > just memory usage. Sure, there are those cases but it'd be unwise to hinge long term decisions on them. It's hard to even argue 16bit pid in legacy code as a significant contributing factor at this point. At any rate, it seems that pid is a global resource which needs to be provisioned for reasonable isolation which is a good reason to consider controlling it via cgroups. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/