From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with ESMTP id 8630F6B0012 for ; Fri, 27 May 2011 19:31:03 -0400 (EDT) Received: from hpaq7.eem.corp.google.com (hpaq7.eem.corp.google.com [172.25.149.7]) by smtp-out.google.com with ESMTP id p4RNUpO9017393 for ; Fri, 27 May 2011 16:30:51 -0700 Received: from pwi15 (pwi15.prod.google.com [10.241.219.15]) by hpaq7.eem.corp.google.com with ESMTP id p4RNUURb014673 (version=TLSv1/SSLv3 cipher=RC4-SHA bits=128 verify=NOT) for ; Fri, 27 May 2011 16:30:37 -0700 Received: by pwi15 with SMTP id 15so1235115pwi.5 for ; Fri, 27 May 2011 16:30:36 -0700 (PDT) Date: Fri, 27 May 2011 16:30:33 -0700 (PDT) From: David Rientjes Subject: Re: [PATCH v2] cpusets: randomize node rotor used in cpuset_mem_spread_node() In-Reply-To: <20110527231700.GA3214@tiehlicka.suse.cz> Message-ID: 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 Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Andrew Morton , KOSAKI Motohiro , LKML , Jack Steiner , Lee Schermerhorn , Christoph Lameter , Pekka Enberg , Paul Menage , Robin Holt , Linus Torvalds , linux-mm@kvack.org 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. -- 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