Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758337AbZIGA0P (ORCPT ); Sun, 6 Sep 2009 20:26:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758206AbZIGA0P (ORCPT ); Sun, 6 Sep 2009 20:26:15 -0400 Received: from mail-px0-f184.google.com ([209.85.216.184]:35645 "EHLO mail-px0-f184.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752931AbZIGA0O (ORCPT ); Sun, 6 Sep 2009 20:26:14 -0400 Subject: Re: question on sched-rt group allocation cap: sched_rt_runtime_us Mime-Version: 1.0 (Apple Message framework v1075.2) Content-Type: text/plain; charset=us-ascii; format=flowed; delsp=yes From: Anirban Sinha In-Reply-To: Date: Sun, 6 Sep 2009 17:26:13 -0700 Cc: Fabio Checconi , Ingo Molnar , a.p.zijlstra@chello.nl, Dario Faggioli , Anirban Sinha Content-Transfer-Encoding: 7bit Message-Id: <93AD5C37-E118-4E5C-8684-EBA548A43492@anirban.org> References: <20090905204037.GE4953@gandalf.sssup.it> <20090906132104.GK14492@gandalf.sssup.it> To: linux-kernel@vger.kernel.org X-Mailer: Apple Mail (2.1075.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1005 Lines: 33 > Running your program I'm unable to reproduce the same issue on a recent > kernel here; for 25ms over 100ms across several runs I get less than 2%. > This number increases, reaching your values, only when using short > periods (where the meaning for short depends on your HZ value), In our kernel, the jiffies are configured as 100 HZ. > which > is something to be expected, due to the fact that rt throttling uses > the tick to charge runtimes to tasks. Hmm. I see. I understand that. > Looking at the git history, there have been several bugfixes to the rt > bandwidth code from 2.6.26, one of them seems to be strictly related to > runtime accounting with your setup: I will apply these patches on Tuesday and rerun the tests. -- 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/