Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754879AbbB0R41 (ORCPT ); Fri, 27 Feb 2015 12:56:27 -0500 Received: from mail-qc0-f173.google.com ([209.85.216.173]:35930 "EHLO mail-qc0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751776AbbB0R4Z (ORCPT ); Fri, 27 Feb 2015 12:56:25 -0500 Date: Fri, 27 Feb 2015 12:56:19 -0500 From: Tejun Heo To: Tim Hockin Cc: Austin S Hemmelgarn , Aleksa Sarai , Li Zefan , mingo@redhat.com, Peter Zijlstra , richard@nod.at, =?iso-8859-1?Q?Fr=E9d=E9ric?= Weisbecker , "linux-kernel@vger.kernel.org" , Cgroups Subject: Re: [PATCH RFC 0/2] add nproc cgroup subsystem Message-ID: <20150227175619.GN3964@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> <20150227174503.GM3964@htj.duckdns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150227174503.GM3964@htj.duckdns.org> 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: 1421 Lines: 31 On Fri, Feb 27, 2015 at 12:45:03PM -0500, Tejun Heo wrote: > If your complaint is that this is taking too long, I hear you, and > there's a certain amount of validity in arguing that upstreaming a > temporary measure is the better trade-off, but the rationale for nproc > (or nfds, or virtual memory, whatever) has been pretty weak otherwise. Also, note that this is subset of a larger problem. e.g. there's a patchset trying to implement writeback IO control from the filesystem layer. cgroup control of writeback has been a thorny issue for over three years now and the rationale for implementing this reversed controlling scheme is about the same - doing it properly is too difficult, let's bolt something on the top as a practical measure. I think it'd be seriously short-sighted to give in and merge all those. These sorts of shortcuts are crippling in the long term. Again, similarly, proper cgroup writeback support is literally right around the corner. The situation sure can be frustrating if you need something now but we can't make decisions solely on that. This is an a lot longer term project and we better, for once, get things right. 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/