From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753353AbYKQTgr (ORCPT ); Mon, 17 Nov 2008 14:36:47 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752009AbYKQTgi (ORCPT ); Mon, 17 Nov 2008 14:36:38 -0500 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:55034 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751997AbYKQTgh (ORCPT ); Mon, 17 Nov 2008 14:36:37 -0500 Date: Mon, 17 Nov 2008 11:36:37 -0800 (PST) Message-Id: <20081117.113637.72930858.davem@davemloft.net> To: mingo@elte.hu Cc: dada1@cosmosbay.com, rjw@sisk.pl, linux-kernel@vger.kernel.org, kernel-testers@vger.kernel.org, cl@linux-foundation.org, efault@gmx.de, a.p.zijlstra@chello.nl, torvalds@linux-foundation.org, shemminger@vyatta.com Subject: Re: [Bug #11308] tbench regression on each kernel release from 2.6.22 -> 2.6.28 From: David Miller In-Reply-To: <20081117170844.GJ12081@elte.hu> References: <20081117161135.GE12081@elte.hu> <49219D36.5020801@cosmosbay.com> <20081117170844.GJ12081@elte.hu> X-Mailer: Mew version 6.1 on Emacs 22.1 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ingo Molnar Date: Mon, 17 Nov 2008 18:08:44 +0100 > Mike Galbraith has been spending months trying to pin down all the > issues. Yes Mike has been doing tireless good work. Another thing I noticed is that because all of the scheduler core operations are now function pointer callbacks, the call chain is deeper for core operations like wake_up(). Much of it used to be completely inlined into try_to_wake_up() With the addition of the RB tree stuff, that adds yet another unavoidable depth of function call. wake_up() is usually at the deepest part of the call chain, so this is a big deal From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [Bug #11308] tbench regression on each kernel release from 2.6.22 -> 2.6.28 Date: Mon, 17 Nov 2008 11:36:37 -0800 (PST) Message-ID: <20081117.113637.72930858.davem@davemloft.net> References: <20081117161135.GE12081@elte.hu> <49219D36.5020801@cosmosbay.com> <20081117170844.GJ12081@elte.hu> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20081117170844.GJ12081-X9Un+BFzKDI@public.gmane.org> Sender: kernel-testers-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: Text/Plain; charset="us-ascii" To: mingo-X9Un+BFzKDI@public.gmane.org Cc: dada1-fPLkHRcR87vqlBn2x/YWAg@public.gmane.org, rjw-KKrjLPT3xs0@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kernel-testers-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, cl-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, efault-Mmb7MZpHnFY@public.gmane.org, a.p.zijlstra-/NLkJaSkS4VmR6Xm/wNWPw@public.gmane.org, torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, shemminger-ZtmgI6mnKB3QT0dZR+AlfA@public.gmane.org From: Ingo Molnar Date: Mon, 17 Nov 2008 18:08:44 +0100 > Mike Galbraith has been spending months trying to pin down all the > issues. Yes Mike has been doing tireless good work. Another thing I noticed is that because all of the scheduler core operations are now function pointer callbacks, the call chain is deeper for core operations like wake_up(). Much of it used to be completely inlined into try_to_wake_up() With the addition of the RB tree stuff, that adds yet another unavoidable depth of function call. wake_up() is usually at the deepest part of the call chain, so this is a big deal