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authorRavikiran G Thirumalai <kiran@scalex86.org>2006-02-04 23:27:56 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-02-05 11:06:53 -0800
commit2e1217cf96b54d3b2d0162930608159e73507fbf (patch)
treeac4eba17cc9cec38e003a4bbabb5dae63934f4ac /mm/slab.c
parent64b4a954b03a1153fb8ae38d6ffbd991e01a1e80 (diff)
downloadlwn-2e1217cf96b54d3b2d0162930608159e73507fbf.tar.gz
lwn-2e1217cf96b54d3b2d0162930608159e73507fbf.zip
[PATCH] NUMA slab locking fixes: move color_next to l3
colour_next is used as an index to add a colouring offset to a new slab in the cache (colour_off * colour_next). Now with the NUMA aware slab allocator, it makes sense to colour slabs added on the same node sequentially with colour_next. This patch moves the colouring index "colour_next" per-node by placing it on kmem_list3 rather than kmem_cache. This also helps simplify locking for CPU up and down paths. Signed-off-by: Alok N Kataria <alokk@calsoftinc.com> Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org> Signed-off-by: Shai Fultheim <shai@scalex86.org> Cc: Christoph Lameter <christoph@lameter.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm/slab.c')
-rw-r--r--mm/slab.c22
1 files changed, 11 insertions, 11 deletions
diff --git a/mm/slab.c b/mm/slab.c
index 71370256a7eb..2317096166dd 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -294,6 +294,7 @@ struct kmem_list3 {
unsigned long next_reap;
int free_touched;
unsigned int free_limit;
+ unsigned int colour_next; /* Per-node cache coloring */
spinlock_t list_lock;
struct array_cache *shared; /* shared per node */
struct array_cache **alien; /* on other nodes */
@@ -344,6 +345,7 @@ static void kmem_list3_init(struct kmem_list3 *parent)
INIT_LIST_HEAD(&parent->slabs_free);
parent->shared = NULL;
parent->alien = NULL;
+ parent->colour_next = 0;
spin_lock_init(&parent->list_lock);
parent->free_objects = 0;
parent->free_touched = 0;
@@ -390,7 +392,6 @@ struct kmem_cache {
size_t colour; /* cache colouring range */
unsigned int colour_off; /* colour offset */
- unsigned int colour_next; /* cache colouring */
struct kmem_cache *slabp_cache;
unsigned int slab_size;
unsigned int dflags; /* dynamic flags */
@@ -1119,7 +1120,6 @@ void __init kmem_cache_init(void)
BUG();
cache_cache.colour = left_over / cache_cache.colour_off;
- cache_cache.colour_next = 0;
cache_cache.slab_size = ALIGN(cache_cache.num * sizeof(kmem_bufctl_t) +
sizeof(struct slab), cache_line_size());
@@ -2324,18 +2324,19 @@ static int cache_grow(struct kmem_cache *cachep, gfp_t flags, int nodeid)
*/
ctor_flags |= SLAB_CTOR_ATOMIC;
- /* About to mess with non-constant members - lock. */
+ /* Take the l3 list lock to change the colour_next on this node */
check_irq_off();
- spin_lock(&cachep->spinlock);
+ l3 = cachep->nodelists[nodeid];
+ spin_lock(&l3->list_lock);
/* Get colour for the slab, and cal the next value. */
- offset = cachep->colour_next;
- cachep->colour_next++;
- if (cachep->colour_next >= cachep->colour)
- cachep->colour_next = 0;
- offset *= cachep->colour_off;
+ offset = l3->colour_next;
+ l3->colour_next++;
+ if (l3->colour_next >= cachep->colour)
+ l3->colour_next = 0;
+ spin_unlock(&l3->list_lock);
- spin_unlock(&cachep->spinlock);
+ offset *= cachep->colour_off;
check_irq_off();
if (local_flags & __GFP_WAIT)
@@ -2367,7 +2368,6 @@ static int cache_grow(struct kmem_cache *cachep, gfp_t flags, int nodeid)
if (local_flags & __GFP_WAIT)
local_irq_disable();
check_irq_off();
- l3 = cachep->nodelists[nodeid];
spin_lock(&l3->list_lock);
/* Make slab active. */