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| author | Christoph Lameter <cl@linux.com> | 2010-12-08 16:22:55 +0100 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2010-12-17 15:07:19 +0100 |
| commit | 909ea96468096b07fbb41aaf69be060d92bd9271 (patch) | |
| tree | a7e015edd96b5f674874fe78cdd889769e130a2a /mm/slab.c | |
| parent | 780f36d8b3fa9572f731d4fb85067b2e45e6f993 (diff) | |
| download | linux-909ea96468096b07fbb41aaf69be060d92bd9271.tar.gz linux-909ea96468096b07fbb41aaf69be060d92bd9271.tar.bz2 linux-909ea96468096b07fbb41aaf69be060d92bd9271.zip | |
core: Replace __get_cpu_var with __this_cpu_read if not used for an address.
__get_cpu_var() can be replaced with this_cpu_read and will then use a
single read instruction with implied address calculation to access the
correct per cpu instance.
However, the address of a per cpu variable passed to __this_cpu_read()
cannot be determined (since it's an implied address conversion through
segment prefixes). Therefore apply this only to uses of __get_cpu_var
where the address of the variable is not used.
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Hugh Dickins <hughd@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'mm/slab.c')
| -rw-r--r-- | mm/slab.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/mm/slab.c b/mm/slab.c index b1e40dafbab3..316d75596f3c 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -829,12 +829,12 @@ static void init_reap_node(int cpu) static void next_reap_node(void) { - int node = __get_cpu_var(slab_reap_node); + int node = __this_cpu_read(slab_reap_node); node = next_node(node, node_online_map); if (unlikely(node >= MAX_NUMNODES)) node = first_node(node_online_map); - __get_cpu_var(slab_reap_node) = node; + __this_cpu_write(slab_reap_node, node); } #else @@ -1012,7 +1012,7 @@ static void __drain_alien_cache(struct kmem_cache *cachep, */ static void reap_alien(struct kmem_cache *cachep, struct kmem_list3 *l3) { - int node = __get_cpu_var(slab_reap_node); + int node = __this_cpu_read(slab_reap_node); if (l3->alien) { struct array_cache *ac = l3->alien[node]; |