Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753452Ab1DOHSv (ORCPT ); Fri, 15 Apr 2011 03:18:51 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:56248 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751796Ab1DOHSu (ORCPT ); Fri, 15 Apr 2011 03:18:50 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 From: KOSAKI Motohiro To: Michal Hocko Subject: Re: cpusets: randomize node rotor used in cpuset_mem_spread_node() Cc: kosaki.motohiro@jp.fujitsu.com, LKML , Jack Steiner , Lee Schermerhorn , Christoph Lameter , Pekka Enberg , Paul Menage , Robin Holt , Andrew Morton , Linus Torvalds In-Reply-To: <20110414160145.0830.A69D9226@jp.fujitsu.com> References: <20110414065146.GA19685@tiehlicka.suse.cz> <20110414160145.0830.A69D9226@jp.fujitsu.com> Message-Id: <20110415161831.12F8.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.56.05 [ja] Date: Fri, 15 Apr 2011 16:18:45 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1118 Lines: 38 Oops. I should have look into !mempolicy part too. I'm sorry. > diff --git a/kernel/fork.c b/kernel/fork.c > index e7548de..f59c686 100644 > --- a/kernel/fork.c > +++ b/kernel/fork.c > @@ -1119,6 +1119,10 @@ static struct task_struct *copy_process(unsigned long clone_flags, > } > mpol_fix_fork_child_flag(p); > #endif > +#ifdef CONFIG_CPUSETS > + p->cpuset_mem_spread_rotor = node_random(&p->mems_allowed); > + p->cpuset_slab_spread_rotor = node_random(&p->mems_allowed); > +#endif Michal, I think this should be #ifdef CONFIG_CPUSETS if (cpuset_do_page_mem_spread()) p->cpuset_mem_spread_rotor = node_random(&p->mems_allowed); if (cpuset_do_slab_mem_spread()) p->cpuset_slab_spread_rotor = node_random(&p->mems_allowed); #endif because 99.999% people don't use cpuset's spread mem/slab feature and get_random_int() isn't zero cost. What do you think? -- 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/