Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760522AbYG1RUb (ORCPT ); Mon, 28 Jul 2008 13:20:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756700AbYG1RUO (ORCPT ); Mon, 28 Jul 2008 13:20:14 -0400 Received: from mail.tmr.com ([64.65.253.246]:41495 "EHLO gaimboi.tmr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759926AbYG1RUN (ORCPT ); Mon, 28 Jul 2008 13:20:13 -0400 Message-ID: <488E01CA.7000302@tmr.com> Date: Mon, 28 Jul 2008 13:28:42 -0400 From: Bill Davidsen Organization: TMR Associates Inc, Schenectady NY User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.0.8) Gecko/20061105 SeaMonkey/1.0.6 MIME-Version: 1.0 To: Paul Menage CC: luis6674@yahoo.com, linux-kernel@vger.kernel.org Subject: Re: How to disable group scheduler correctly? References: <842240.12654.qm@web53310.mail.re2.yahoo.com> <488D03A9.4020103@tmr.com> <6599ad830807280947j21fda44ajd51ce1dd523d9472@mail.gmail.com> In-Reply-To: <6599ad830807280947j21fda44ajd51ce1dd523d9472@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1456 Lines: 34 Paul Menage wrote: > On Sun, Jul 27, 2008 at 4:24 PM, Bill Davidsen wrote: > >> Would be nice to have a clean way to do this at runtime, so you could run a >> distribution kernel and just avoid the group part of the scheduling. >> > > If the cgroups scheduler is enabled but you don't actually create any > cpu scheduler cgroups, then you're just scheduling across a single > group that contains all processes/threads. Is that distinguishable > from not having group scheduling at all? > In decisions, hopefully not. But given that there are other places in kernel which allow code to be bypassed completely, a flag which would simply avoid ever going into the code would not be a new idea. In the network code there are flags to prevent passing packets in a bridge through iptables, something similar could be provided in scheduling. It actually makes sense to default the flag to "no cgroups" asnd only enable it if cgroups have been defined. There is no optimization faster than not executing the code. -- Bill Davidsen "Woe unto the statesman who makes war without a reason that will still be valid when the war is over..." Otto von Bismark -- 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/