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 SMTP id E1CE86B01EF for ; Sun, 18 Apr 2010 22:36:49 -0400 (EDT) Received: from m1.gw.fujitsu.co.jp ([10.0.50.71]) by fgwmail7.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o3J2ajAl021970 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Mon, 19 Apr 2010 11:36:45 +0900 Received: from smail (m1 [127.0.0.1]) by outgoing.m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 9131A45DE4D for ; Mon, 19 Apr 2010 11:36:45 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (s1.gw.fujitsu.co.jp [10.0.50.91]) by m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 5B59045DE50 for ; Mon, 19 Apr 2010 11:36:45 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id 3ABB61DB804D for ; Mon, 19 Apr 2010 11:36:45 +0900 (JST) Received: from m108.s.css.fujitsu.com (m108.s.css.fujitsu.com [10.249.87.108]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id CD5521DB8040 for ; Mon, 19 Apr 2010 11:36:44 +0900 (JST) Date: Mon, 19 Apr 2010 11:32:47 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH 1/8] numa: add generic percpu var numa_node_id() implementation Message-Id: <20100419113247.27fd0ea0.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20100415172956.8801.18133.sendpatchset@localhost.localdomain> References: <20100415172950.8801.60358.sendpatchset@localhost.localdomain> <20100415172956.8801.18133.sendpatchset@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Lee Schermerhorn Cc: linux-mm@kvack.org, linux-numa@vger.kernel.org, Tejun Heo , Mel Gorman , andi@firstfloor.org, Christoph Lameter , Nick Piggin , David Rientjes , eric.whitney@hp.com, Andrew Morton List-ID: On Thu, 15 Apr 2010 13:29:56 -0400 Lee Schermerhorn wrote: > Against: 2.6.34-rc3-mmotm-100405-1609 > > Rework the generic version of the numa_node_id() function to use the > new generic percpu variable infrastructure. > > Guard the new implementation with a new config option: > > CONFIG_USE_PERCPU_NUMA_NODE_ID. > > Archs which support this new implemention will default this option > to 'y' when NUMA is configured. This config option could be removed > if/when all archs switch over to the generic percpu implementation > of numa_node_id(). Arch support involves: > > 1) converting any existing per cpu variable implementations to use > this implementation. x86_64 is an instance of such an arch. > 2) archs that don't use a per cpu variable for numa_node_id() will > need to initialize the new per cpu variable "numa_node" as cpus > are brought on-line. ia64 is an example. > 3) Defining USE_PERCPU_NUMA_NODE_ID in arch dependent Kconfig--e.g., > when NUMA is configured. This is required because I have > retained the old implementation by default to allow archs to > be modified incrementally, as desired. > > Subsequent patches will convert x86_64 and ia64 to use this > implemenation. > > Signed-off-by: Lee Schermerhorn Reviewed-by: KAMEZAWA Hiroyuki > > --- > > V0: > # From cl@linux-foundation.org Wed Nov 4 10:36:12 2009 > # Date: Wed, 4 Nov 2009 12:35:14 -0500 (EST) > # From: Christoph Lameter > # To: Lee Schermerhorn > # Subject: Re: [PATCH/RFC] slab: handle memoryless nodes efficiently > # > # I have a very early form of a draft of a patch here that genericizes > # numa_node_id(). Uses the new generic this_cpu_xxx stuff. > # > # Not complete. > > V1: > + split out x86 specific changes to subsequent patch > + split out "numa_mem_id()" and related changes to separate patch > + moved generic definitions of __this_cpu_xxx from linux/percpu.h > to asm-generic/percpu.h where asm/percpu.h and other asm hdrs > can use them. > + export new percpu symbol 'numa_node' in mm/percpu.h > + include in for use by new > numa_node_id(). > > V2: > + add back the #ifndef/#endif guard around numa_node_id() so that archs > can override generic definition > + add generic stub for set_numa_node() > + use generic percpu numa_node_id() only if enabled by > CONFIG_USE_PERCPU_NUMA_NODE_ID > to allow incremental per arch support. This option could be removed when/if > all archs that support NUMA support this option. > > V3: > + separated the rework of linux/percpu.h into another [preceding] patch. > + moved definition of the numa_node percpu variable from mm/percpu.c to > mm/page-alloc.c > + moved premature definition of cpu_to_mem() to later patch. > > V4: > + topology.h: include rather than > Requires Tejun Heo's percpu.h/slab.h cleanup series > > include/linux/topology.h | 33 ++++++++++++++++++++++++++++----- > mm/page_alloc.c | 5 +++++ > 2 files changed, 33 insertions(+), 5 deletions(-) > > Index: linux-2.6.34-rc3-mmotm-100405-1609/mm/page_alloc.c > =================================================================== > --- linux-2.6.34-rc3-mmotm-100405-1609.orig/mm/page_alloc.c 2010-04-07 10:04:04.000000000 -0400 > +++ linux-2.6.34-rc3-mmotm-100405-1609/mm/page_alloc.c 2010-04-07 10:10:23.000000000 -0400 > @@ -56,6 +56,11 @@ > #include > #include "internal.h" > > +#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID > +DEFINE_PER_CPU(int, numa_node); > +EXPORT_PER_CPU_SYMBOL(numa_node); > +#endif > + > /* > * Array of node states. > */ > Index: linux-2.6.34-rc3-mmotm-100405-1609/include/linux/topology.h > =================================================================== > --- linux-2.6.34-rc3-mmotm-100405-1609.orig/include/linux/topology.h 2010-04-07 09:49:13.000000000 -0400 > +++ linux-2.6.34-rc3-mmotm-100405-1609/include/linux/topology.h 2010-04-07 10:10:23.000000000 -0400 > @@ -31,6 +31,7 @@ > #include > #include > #include > +#include > #include > > #ifndef node_has_online_mem > @@ -203,8 +204,35 @@ int arch_update_cpu_topology(void); > #ifndef SD_NODE_INIT > #error Please define an appropriate SD_NODE_INIT in include/asm/topology.h!!! > #endif > + > #endif /* CONFIG_NUMA */ > > +#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID > +DECLARE_PER_CPU(int, numa_node); > + > +#ifndef numa_node_id > +/* Returns the number of the current Node. */ > +#define numa_node_id() __this_cpu_read(numa_node) > +#endif > + > +#ifndef cpu_to_node > +#define cpu_to_node(__cpu) per_cpu(numa_node, (__cpu)) > +#endif > + > +#ifndef set_numa_node > +#define set_numa_node(__node) percpu_write(numa_node, __node) > +#endif > + > +#else /* !CONFIG_USE_PERCPU_NUMA_NODE_ID */ > + > +/* Returns the number of the current Node. */ > +#ifndef numa_node_id > +#define numa_node_id() (cpu_to_node(raw_smp_processor_id())) > + > +#endif > + > +#endif /* [!]CONFIG_USE_PERCPU_NUMA_NODE_ID */ > + > #ifndef topology_physical_package_id > #define topology_physical_package_id(cpu) ((void)(cpu), -1) > #endif > @@ -218,9 +246,4 @@ int arch_update_cpu_topology(void); > #define topology_core_cpumask(cpu) cpumask_of(cpu) > #endif > > -/* Returns the number of the current Node. */ > -#ifndef numa_node_id > -#define numa_node_id() (cpu_to_node(raw_smp_processor_id())) > -#endif > - > #endif /* _LINUX_TOPOLOGY_H */ > > -- > 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 > -- 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