From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with ESMTP id 154596B0012 for ; Fri, 27 May 2011 17:21:11 -0400 (EDT) Date: Fri, 27 May 2011 14:20:51 -0700 From: Andrew Morton Subject: Re: [PATCH v2] cpusets: randomize node rotor used in cpuset_mem_spread_node() Message-Id: <20110527142051.d7ec3784.akpm@linux-foundation.org> In-Reply-To: <20110527124705.GB4067@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> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko 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 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 #define node_online_map node_states[N_ONLINE] It's beyond weird that we implement node_random() if defined(CONFIG_NUMA) && (MAX_NUMNODES > 1), and only use it if defined(CONFIG_CPUSETS). -- 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