From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [RFC][PATCH 2/2] quicklist shouldn't be proportional to # of CPUs From: Peter Zijlstra In-Reply-To: <20080821002757.b7c807ad.akpm@linux-foundation.org> References: <20080820195021.12E7.KOSAKI.MOTOHIRO@jp.fujitsu.com> <20080820200709.12F0.KOSAKI.MOTOHIRO@jp.fujitsu.com> <20080820234615.258a9c04.akpm@linux-foundation.org> <20080821.001322.236658980.davem@davemloft.net> <20080821002757.b7c807ad.akpm@linux-foundation.org> Content-Type: text/plain Date: Thu, 21 Aug 2008 11:32:34 +0200 Message-Id: <1219311154.8651.96.camel@twins> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: David Miller , kosaki.motohiro@jp.fujitsu.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, cl@linux-foundation.org, tokunaga.keiich@jp.fujitsu.com, travis List-ID: On Thu, 2008-08-21 at 00:27 -0700, Andrew Morton wrote: > On Thu, 21 Aug 2008 00:13:22 -0700 (PDT) David Miller wrote: > > > From: Andrew Morton > > Date: Wed, 20 Aug 2008 23:46:15 -0700 > > > > > On Wed, 20 Aug 2008 20:08:13 +0900 KOSAKI Motohiro wrote: > > > > > > > + num_cpus_per_node = cpus_weight_nr(node_to_cpumask(node)); > > > > > > sparc64 allmodconfig: > > > > > > mm/quicklist.c: In function `max_pages': > > > mm/quicklist.c:44: error: invalid lvalue in unary `&' > > > > > > we seem to have a made a spectacular mess of cpumasks lately. > > > > It should explode similarly on x86, since it also defines node_to_cpumask() > > as an inline function. > > > > IA64 seems to be one of the few platforms to define this as a macro > > evaluating to the node-to-cpumask array entry, so it's clear what > > platform Motohiro-san did build testing on :-) > > Seems to compile OK on x86_32, x86_64, ia64 and powerpc for some reason. > > This seems to fix things on sparc64: > > --- a/mm/quicklist.c~mm-quicklist-shouldnt-be-proportional-to-number-of-cpus-fix > +++ a/mm/quicklist.c > @@ -28,7 +28,7 @@ static unsigned long max_pages(unsigned > unsigned long node_free_pages, max; > int node = numa_node_id(); > struct zone *zones = NODE_DATA(node)->node_zones; > - int num_cpus_per_node; > + cpumask_t node_cpumask; > > node_free_pages = > #ifdef CONFIG_ZONE_DMA > @@ -41,8 +41,8 @@ static unsigned long max_pages(unsigned > > max = node_free_pages / FRACTION_OF_NODE_MEM; > > - num_cpus_per_node = cpus_weight_nr(node_to_cpumask(node)); > - max /= num_cpus_per_node; > + node_cpumask = node_to_cpumask(node); > + max /= cpus_weight_nr(node_cpumask); > > return max(max, min_pages); > } humm, I thought we wanted to keep cpumask_t stuff away from our stack - since on insanely large SGI boxen (/me looks at mike) the thing becomes 512 bytes. -- 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/ . Don't email: email@kvack.org