Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757525Ab1E0XRN (ORCPT ); Fri, 27 May 2011 19:17:13 -0400 Received: from cantor2.suse.de ([195.135.220.15]:36617 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757352Ab1E0XRL (ORCPT ); Fri, 27 May 2011 19:17:11 -0400 Date: Sat, 28 May 2011 01:17:08 +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: <20110527231708.GB3214@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-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: 2264 Lines: 67 On Fri 27-05-11 12:07:30, David Rientjes wrote: > On Fri, 27 May 2011, Michal Hocko wrote: > > > > alpha allmodconfig: > > > > > > kernel/built-in.o: In function `cpuset_slab_spread_node': > > > (.text+0x67360): undefined reference to `node_random' > > > kernel/built-in.o: In function `cpuset_slab_spread_node': > > > (.text+0x67368): undefined reference to `node_random' > > > kernel/built-in.o: In function `cpuset_mem_spread_node': > > > (.text+0x673b8): undefined reference to `node_random' > > > kernel/built-in.o: In function `cpuset_mem_spread_node': > > > (.text+0x673c0): undefined reference to `node_random' > > > > > > because it has CONFIG_NUMA=n, CONFIG_NODES_SHIFT=7. > > > > non-NUMA with MAX_NUMA_NODES? Hmm, really weird and looks like a numa > > misuse. > > > > CONFIG_NODES_SHIFT is used for UMA machines that are using DISCONTIGMEM > usually because they have very large holes; such machines don't need > things like mempolicies but do need the data structures that abstract > ranges of memory in the physical address space. This build breakage > probably isn't restricted to only alpha, you could probably see it with at > least ia64 and mips as well. Hmmm. I just find strange that some UMA arch uses functions like {first,next}_online_node. [...] > > +/* > > + * Return the bit number of a random bit set in the nodemask. > > + * (returns -1 if nodemask is empty) > > + */ > > +static inline int node_random(const nodemask_t *maskp) > > +{ > > + int w, bit = -1; > > + > > + w = nodes_weight(*maskp); > > + if (w) > > + bit = bitmap_ord_to_pos(maskp->bits, > > + get_random_int() % w, MAX_NUMNODES); > > + return bit; > > +} > > > > #else > > > > Probably should have a no-op definition when MAX_NUMNODES == 1 that just > returns 0? There is one, which has been added by the patch which introduced the function. This is just an incremental patch for the compilation fix. -- 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/