From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752901AbZGXNcA (ORCPT ); Fri, 24 Jul 2009 09:32:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752715AbZGXNb7 (ORCPT ); Fri, 24 Jul 2009 09:31:59 -0400 Received: from casper.infradead.org ([85.118.1.10]:55285 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752413AbZGXNb7 (ORCPT ); Fri, 24 Jul 2009 09:31:59 -0400 Subject: Re: report a bug about sched_rt From: Peter Zijlstra To: sen wang Cc: mingo@elte.hu, akpm@linux-foundation.org, kernel@kolivas.org, npiggin@suse.de, arjan@infradead.org, linux-arm-kernel@lists.arm.linux.org.uk, linux-kernel@vger.kernel.org In-Reply-To: <454c71700907240626w127fd890ufa91ef90cbcaaa@mail.gmail.com> References: <454c71700907240357l61f5c4fajaca73db0fba7db8@mail.gmail.com> <1248437670.6987.26.camel@twins> <454c71700907240604h4673f117j8ed58b9f2ee54798@mail.gmail.com> <1248441290.6987.52.camel@twins> <454c71700907240626w127fd890ufa91ef90cbcaaa@mail.gmail.com> Content-Type: text/plain Content-Transfer-Encoding: 7bit Date: Fri, 24 Jul 2009 15:33:35 +0200 Message-Id: <1248442415.6987.56.camel@twins> Mime-Version: 1.0 X-Mailer: Evolution 2.26.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2009-07-24 at 21:26 +0800, sen wang wrote: > don't tell me what theory. don't be so doctrinairism! OK? > If cpu is free and there is a running state task,how can you scdedule > idle task up? > I tell you again:we are not talking about a bandwidth of 100% for RT! > Bug lies in the bandwidth of (100- X)%.(X<100) > even in the time of 100-X,if there is a rt task, you should not idle() > the system. *sigh* Yes we should. I appreciate that you might assume otherwise, but you're wrong. Suppose you have two competing bandwidth groups, which one will run over, to what purpose? Also, your next top post will go to /dev/null.