Messages in this thread Patch in this message | | | Subject | Re: [patch 2/2]slub: add a type for slab partial list position | From | Shaohua Li <> | Date | Wed, 24 Aug 2011 08:57:52 +0800 |
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On Tue, 2011-08-23 at 23:25 +0800, Christoph Lameter wrote: > On Tue, 23 Aug 2011, Shaohua Li wrote: > > > Adding slab to partial list head/tail is sensentive to performance. > > So adding a type to document it to avoid we get it wrong. > > I think that if you want to make it more descriptive then using the stats > values (DEACTIVATE_TO_TAIL/HEAD) would avoid having to introduce an > additional enum and it would also avoid the if statement in the stat call. ok, that's better.
Subject: slub: explicitly document position of inserting slab to partial list
Adding slab to partial list head/tail is sensitive to performance. So explicitly uses DEACTIVATE_TO_TAIL/DEACTIVATE_TO_HEAD to document it to avoid we get it wrong.
Signed-off-by: Shaohua Li <shli@kernel.org> Signed-off-by: Shaohua Li <shaohua.li@intel.com> --- mm/slub.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
Index: linux/mm/slub.c =================================================================== --- linux.orig/mm/slub.c 2011-08-24 08:46:27.000000000 +0800 +++ linux/mm/slub.c 2011-08-24 08:49:41.000000000 +0800 @@ -1534,7 +1534,7 @@ static inline void add_partial(struct km struct page *page, int tail) { n->nr_partial++; - if (tail) + if (tail == DEACTIVATE_TO_TAIL) list_add_tail(&page->lru, &n->partial); else list_add(&page->lru, &n->partial); @@ -1781,13 +1781,13 @@ static void deactivate_slab(struct kmem_ enum slab_modes l = M_NONE, m = M_NONE; void *freelist; void *nextfree; - int tail = 0; + int tail = DEACTIVATE_TO_HEAD; struct page new; struct page old; if (page->freelist) { stat(s, DEACTIVATE_REMOTE_FREES); - tail = 1; + tail = DEACTIVATE_TO_TAIL; } c->tid = next_tid(c->tid); @@ -1893,7 +1893,7 @@ redo: if (m == M_PARTIAL) { add_partial(n, page, tail); - stat(s, tail ? DEACTIVATE_TO_TAIL : DEACTIVATE_TO_HEAD); + stat(s, tail); } else if (m == M_FULL) { @@ -2377,7 +2377,7 @@ static void __slab_free(struct kmem_cach */ if (unlikely(!prior)) { remove_full(s, page); - add_partial(n, page, 1); + add_partial(n, page, DEACTIVATE_TO_TAIL); stat(s, FREE_ADD_PARTIAL); } } @@ -2695,7 +2695,7 @@ static void early_kmem_cache_node_alloc( init_kmem_cache_node(n, kmem_cache_node); inc_slabs_node(kmem_cache_node, node, page->objects); - add_partial(n, page, 0); + add_partial(n, page, DEACTIVATE_TO_HEAD); } static void free_kmem_cache_nodes(struct kmem_cache *s)
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