diff options
author | Christoph Lameter <clameter@sgi.com> | 2007-05-16 22:10:53 -0700 |
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committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-17 05:23:03 -0700 |
commit | 4b6f0750457db1f573eb6226960a432da3be8fe2 (patch) | |
tree | 9e71084c892b595e4b7383d152d7ebeea936934b /mm | |
parent | 3ca12ee549f7837b8a685dddc9515f9fc28434ee (diff) | |
download | linux-3.10-4b6f0750457db1f573eb6226960a432da3be8fe2.tar.gz linux-3.10-4b6f0750457db1f573eb6226960a432da3be8fe2.tar.bz2 linux-3.10-4b6f0750457db1f573eb6226960a432da3be8fe2.zip |
SLUB: Define functions for cpu slab handling instead of using PageActive
Use inline functions to access the per cpu bit. Intoduce the notion of
"freezing" a slab to make things more understandable.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
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/slub.c | 57 |
1 files changed, 38 insertions, 19 deletions
diff --git a/mm/slub.c b/mm/slub.c index 022c1b4d74d..ce96d485a88 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -78,10 +78,18 @@ * * Overloading of page flags that are otherwise used for LRU management. * - * PageActive The slab is used as a cpu cache. Allocations - * may be performed from the slab. The slab is not - * on any slab list and cannot be moved onto one. - * The cpu slab may be equipped with an additioanl + * PageActive The slab is frozen and exempt from list processing. + * This means that the slab is dedicated to a purpose + * such as satisfying allocations for a specific + * processor. Objects may be freed in the slab while + * it is frozen but slab_free will then skip the usual + * list operations. It is up to the processor holding + * the slab to integrate the slab into the slab lists + * when the slab is no longer needed. + * + * One use of this flag is to mark slabs that are + * used for allocations. Then such a slab becomes a cpu + * slab. The cpu slab may be equipped with an additional * lockless_freelist that allows lockless access to * free objects in addition to the regular freelist * that requires the slab lock. @@ -91,6 +99,21 @@ * the fast path and disables lockless freelists. */ +static inline int SlabFrozen(struct page *page) +{ + return PageActive(page); +} + +static inline void SetSlabFrozen(struct page *page) +{ + SetPageActive(page); +} + +static inline void ClearSlabFrozen(struct page *page) +{ + ClearPageActive(page); +} + static inline int SlabDebug(struct page *page) { #ifdef CONFIG_SLUB_DEBUG @@ -1135,11 +1158,12 @@ static void remove_partial(struct kmem_cache *s, * * Must hold list_lock. */ -static int lock_and_del_slab(struct kmem_cache_node *n, struct page *page) +static inline int lock_and_freeze_slab(struct kmem_cache_node *n, struct page *page) { if (slab_trylock(page)) { list_del(&page->lru); n->nr_partial--; + SetSlabFrozen(page); return 1; } return 0; @@ -1163,7 +1187,7 @@ static struct page *get_partial_node(struct kmem_cache_node *n) spin_lock(&n->list_lock); list_for_each_entry(page, &n->partial, lru) - if (lock_and_del_slab(n, page)) + if (lock_and_freeze_slab(n, page)) goto out; page = NULL; out: @@ -1242,10 +1266,11 @@ static struct page *get_partial(struct kmem_cache *s, gfp_t flags, int node) * * On exit the slab lock will have been dropped. */ -static void putback_slab(struct kmem_cache *s, struct page *page) +static void unfreeze_slab(struct kmem_cache *s, struct page *page) { struct kmem_cache_node *n = get_node(s, page_to_nid(page)); + ClearSlabFrozen(page); if (page->inuse) { if (page->freelist) @@ -1296,9 +1321,7 @@ static void deactivate_slab(struct kmem_cache *s, struct page *page, int cpu) page->inuse--; } s->cpu_slab[cpu] = NULL; - ClearPageActive(page); - - putback_slab(s, page); + unfreeze_slab(s, page); } static void flush_slab(struct kmem_cache *s, struct page *page, int cpu) @@ -1389,9 +1412,7 @@ another_slab: new_slab: page = get_partial(s, gfpflags, node); if (page) { -have_slab: s->cpu_slab[cpu] = page; - SetPageActive(page); goto load_freelist; } @@ -1421,7 +1442,9 @@ have_slab: flush_slab(s, s->cpu_slab[cpu], cpu); } slab_lock(page); - goto have_slab; + SetSlabFrozen(page); + s->cpu_slab[cpu] = page; + goto load_freelist; } return NULL; debug: @@ -1508,11 +1531,7 @@ checks_ok: page->freelist = object; page->inuse--; - if (unlikely(PageActive(page))) - /* - * Cpu slabs are never on partial lists and are - * never freed. - */ + if (unlikely(SlabFrozen(page))) goto out_unlock; if (unlikely(!page->inuse)) @@ -1544,7 +1563,7 @@ slab_empty: debug: if (!free_object_checks(s, page, x)) goto out_unlock; - if (!PageActive(page) && !page->freelist) + if (!SlabFrozen(page) && !page->freelist) remove_full(s, page); if (s->flags & SLAB_STORE_USER) set_track(s, x, TRACK_FREE, addr); |