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| author | Lee Schermerhorn <lee.schermerhorn@hp.com> | 2010-05-26 23:44:56 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-05-27 18:12:57 +0200 |
| commit | 7281201922a0063fa60804ce39c277fc98142a47 (patch) | |
| tree | 4bf089d077b1055e54bc1411dcc0db121d01d9fa /mm | |
| parent | Documentation/filesystems/Locking: update documentation on llseek() wrt BKL (diff) | |
| download | linux-7281201922a0063fa60804ce39c277fc98142a47.tar.xz linux-7281201922a0063fa60804ce39c277fc98142a47.zip | |
numa: add generic percpu var numa_node_id() implementation
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 <lee.schermerhorn@hp.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Nick Piggin <npiggin@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Eric Whitney <eric.whitney@hp.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/page_alloc.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 08b349931ebc..6fe1b65ee1a8 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -57,6 +57,11 @@ #include <asm/div64.h> #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. */ |