Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757628Ab1E0Xik (ORCPT ); Fri, 27 May 2011 19:38:40 -0400 Received: from cantor.suse.de ([195.135.220.2]:36371 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757046Ab1E0Xij (ORCPT ); Fri, 27 May 2011 19:38:39 -0400 Date: Sat, 28 May 2011 01:38:34 +0200 From: Michal Hocko To: David Rientjes Cc: Andrew Morton , KOSAKI Motohiro , LKML , Jack Steiner , Lee Schermerhorn , Christoph Lameter , Pekka Enberg , Paul Menage , Robin Holt , Linus Torvalds , linux-mm@kvack.org Subject: Re: [PATCH v2] cpusets: randomize node rotor used in cpuset_mem_spread_node() Message-ID: <20110527233834.GA4276@tiehlicka.suse.cz> References: <20110414065146.GA19685@tiehlicka.suse.cz> <20110414160145.0830.A69D9226@jp.fujitsu.com> <20110415161831.12F8.A69D9226@jp.fujitsu.com> <20110415082051.GB8828@tiehlicka.suse.cz> <20110526153319.b7e8c0b6.akpm@linux-foundation.org> <20110527124705.GB4067@tiehlicka.suse.cz> <20110527142051.d7ec3784.akpm@linux-foundation.org> <20110527231700.GA3214@tiehlicka.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1991 Lines: 55 On Fri 27-05-11 16:30:33, David Rientjes wrote: > On Sat, 28 May 2011, Michal Hocko wrote: > > > > --- a/include/linux/nodemask.h~cpusets-randomize-node-rotor-used-in-cpuset_mem_spread_node-fix-2 > > > +++ a/include/linux/nodemask.h > > > @@ -433,8 +433,6 @@ static inline void node_set_offline(int > > > nr_online_nodes = num_node_state(N_ONLINE); > > > } > > > > > > -extern int node_random(const nodemask_t *maskp); > > > - > > > #else > > > > > > static inline int node_state(int node, enum node_states state) > > > @@ -466,7 +464,15 @@ static inline int num_node_state(enum no > > > #define node_set_online(node) node_set_state((node), N_ONLINE) > > > #define node_set_offline(node) node_clear_state((node), N_ONLINE) > > > > > > -static inline int node_random(const nodemask_t *mask) { return 0; } > > > +#endif > > > + > > > +#if defined(CONFIG_NUMA) && (MAX_NUMNODES > 1) > > > +extern int node_random(const nodemask_t *maskp); > > > +#else > > > +static inline int node_random(const nodemask_t *mask) > > > +{ > > > + return 0; > > > +} > > > #endif > > > > I have to admit that I quite don't understand concept of several nodes > > with UMA archs but do we really want to provide the sane node all the > > time? > > > > They aren't nodes on UMA machines, they are memory regions for > DISCONTIGMEM which are separated by large holes in the address space. > These archs will never sanely use node_random(), so it doesn't really > matter except for CONFIG_NUMA where MAX_NUMNODES > 1, since they won't be > selecting random memory regions. OK, I see. Then it makes much more sense. Thanks for clarification. -- Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic -- 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/