From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752146AbZJXUGX (ORCPT ); Sat, 24 Oct 2009 16:06:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751939AbZJXUGX (ORCPT ); Sat, 24 Oct 2009 16:06:23 -0400 Received: from casper.infradead.org ([85.118.1.10]:35618 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751905AbZJXUGW (ORCPT ); Sat, 24 Oct 2009 16:06:22 -0400 Date: Sat, 24 Oct 2009 13:07:28 -0700 From: Arjan van de Ven To: Arjan van de Ven Cc: Peter Zijlstra , mingo@elte.hu, linux-kernel@vger.kernel.org Subject: [PATCH 3/3] sched: Disable affine wakeups by default Message-ID: <20091024130728.051c4d7c@infradead.org> In-Reply-To: <20091024130432.0c46ef27@infradead.org> References: <20091024125853.35143117@infradead.org> <20091024130432.0c46ef27@infradead.org> Organization: Intel X-Mailer: Claws Mail 3.7.2 (GTK+ 2.16.6; i586-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Subject: sched: Disable affine wakeups by default From: Arjan van de Ven The global affine wakeup scheduler feature sounds nice, but there is a problem with this: This is ALSO a per scheduler domain feature already. By having the global scheduler feature enabled by default, the scheduler domains no longer have the option to opt out. There are domains (for example the HT/SMT domain) that have good reason to want to opt out of this feature. With this patch they can opt out, while all other domains currently default to the affine setting anyway. Signed-off-by: Arjan van de Ven diff --git a/kernel/sched_features.h b/kernel/sched_features.h index 0d94083..58c2ea7 100644 --- a/kernel/sched_features.h +++ b/kernel/sched_features.h @@ -72,7 +72,7 @@ SCHED_FEAT(SYNC_WAKEUPS, 1) * improve cache locality. Typically used with SYNC wakeups as * generated by pipes and the like, see also SYNC_WAKEUPS. */ -SCHED_FEAT(AFFINE_WAKEUPS, 1) +SCHED_FEAT(AFFINE_WAKEUPS, 0) /* * Weaken SYNC hint based on overlap -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org