Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753665Ab2EFNKM (ORCPT ); Sun, 6 May 2012 09:10:12 -0400 Received: from mailout-de.gmx.net ([213.165.64.22]:46378 "HELO mailout-de.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753543Ab2EFNKK (ORCPT ); Sun, 6 May 2012 09:10:10 -0400 X-Authenticated: #14349625 X-Provags-ID: V01U2FsdGVkX19qQ/d5z2Fq5/Stiho7miWfY8MTHdXF6vX2AvbE4J bufWwjNf1hdwYm Message-ID: <1336309806.7351.19.camel@marge.simpson.net> Subject: Re: [PATCH] clockevents: Per cpu tick skew boot option From: Mike Galbraith To: LKML Cc: Thomas Gleixner Date: Sun, 06 May 2012 15:10:06 +0200 In-Reply-To: <1336309127.7351.13.camel@marge.simpson.net> References: <1336309127.7351.13.camel@marge.simpson.net> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 X-Y-GMX-Trusted: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 791 Lines: 20 On Sun, 2012-05-06 at 14:58 +0200, Mike Galbraith wrote: > - 0209f649 rcu: limit rcu_node leaf-level fanout > This patch was born to combat lock contention which testing showed > to have been _induced by_ skew removal. Skew the tick, contention > disappeared virtually completely. P.S. This boot option patch will complement a proposed patch by Paul McKenney to allow boot time fanout configuration. Between the two, users will then be able to boot time select the tradeoff they need for optimal performance of their systems. -Mike -- 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/