From: Paul Jackson Date: Fri, 24 Mar 2006 11:16:12 +0000 (-0800) Subject: [PATCH] cpuset: memory_spread_slab drop useless PF_SPREAD_PAGE check X-Git-Tag: v2.6.17-rc1~919 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=b2455396be35383c4eebc6745cc718b1dd9e23df;p=karo-tx-linux.git [PATCH] cpuset: memory_spread_slab drop useless PF_SPREAD_PAGE check The hook in the slab cache allocation path to handle cpuset memory spreading for tasks in cpusets with 'memory_spread_slab' enabled has a modest performance bug. The hook calls into the memory spreading handler alternate_node_alloc() if either of 'memory_spread_slab' or 'memory_spread_page' is enabled, even though the handler does nothing (albeit harmlessly) for the page case Fix - drop PF_SPREAD_PAGE from the set of flag bits that are used to trigger a call to alternate_node_alloc(). The page case is handled by separate hooks -- see the calls conditioned on cpuset_do_page_mem_spread() in mm/filemap.c Signed-off-by: Paul Jackson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/mm/slab.c b/mm/slab.c index f80b52388a12..26138c9f8f00 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -2809,8 +2809,7 @@ static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags) struct array_cache *ac; #ifdef CONFIG_NUMA - if (unlikely(current->flags & (PF_SPREAD_PAGE | PF_SPREAD_SLAB | - PF_MEMPOLICY))) { + if (unlikely(current->flags & (PF_SPREAD_SLAB | PF_MEMPOLICY))) { objp = alternate_node_alloc(cachep, flags); if (objp != NULL) return objp; @@ -2849,7 +2848,7 @@ static __always_inline void *__cache_alloc(struct kmem_cache *cachep, #ifdef CONFIG_NUMA /* - * Try allocating on another node if PF_SPREAD_PAGE|PF_SPREAD_SLAB|PF_MEMPOLICY. + * Try allocating on another node if PF_SPREAD_SLAB|PF_MEMPOLICY. * * If we are in_interrupt, then process context, including cpusets and * mempolicy, may not apply and should not be used for allocation policy.