From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with ESMTP id 2BE9D6B0012 for ; Fri, 27 May 2011 19:17:05 -0400 (EDT) Date: Sat, 28 May 2011 01:17:00 +0200 From: Michal Hocko Subject: Re: [PATCH v2] cpusets: randomize node rotor used in cpuset_mem_spread_node() Message-ID: <20110527231700.GA3214@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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110527142051.d7ec3784.akpm@linux-foundation.org> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: KOSAKI Motohiro , LKML , Jack Steiner , Lee Schermerhorn , Christoph Lameter , Pekka Enberg , Paul Menage , Robin Holt , Linus Torvalds , linux-mm@kvack.org On Fri 27-05-11 14:20:51, Andrew Morton wrote: > On Fri, 27 May 2011 14:47:05 +0200 > Michal Hocko wrote: > > > > We use "#if MAX_NUMNODES > 1" in nodemask.h, but we use CONFIG_NUMA > > > when deciding to build mempolicy.o. That's a bit odd - why didn't > > > nodemask.h use CONFIG_NUMA? > > > > We have this since the kernel git age. I guess this is just for > > optimizations where some functions can be NOOP when there is only one > > node. > > > > I know that this is ugly but what if we just define node_random in the > > header? > > I think I prefer this: > > --- 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? -- Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org