[slubllv4 03/16] slub: Move page->frozen handling near where the page->freelist handling occurs

Christoph Lameter
2011-05-06T18:10:52Z

[-- Attachment #1: frozen_move --]
[-- Type: text/plain, Size: 2006 bytes --]

This is necessary because the frozen bit has to be handled in the same cmpxchg_double
with the freelist and the counters.

Signed-off-by: Christoph Lameter <cl@linux.com>

---
mm/slub.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

Index: linux-2.6/mm/slub.c
===================================================================
--- linux-2.6.orig/mm/slub.c 2011-05-05 15:28:45.000000000 -0500
+++ linux-2.6/mm/slub.c 2011-05-05 15:29:17.000000000 -0500
@@ -1264,6 +1264,7 @@ static struct page *new_slab(struct kmem

page->freelist = start;
page->inuse = 0;
+ page->frozen = 1;
out:
return page;
}
@@ -1402,7 +1403,6 @@ static inline int lock_and_freeze_slab(s
{
if (slab_trylock(page)) {
__remove_partial(n, page);
- page->frozen = 1;
return 1;
}
return 0;
@@ -1516,7 +1516,6 @@ static void unfreeze_slab(struct kmem_ca
{
struct kmem_cache_node *n = get_node(s, page_to_nid(page));

- page->frozen = 0;
if (page->inuse) {

if (page->freelist) {
@@ -1649,6 +1648,7 @@ static void deactivate_slab(struct kmem_
}
c->page = NULL;
c->tid = next_tid(c->tid);
+ page->frozen = 0;
unfreeze_slab(s, page, tail);
}

@@ -1809,6 +1809,8 @@ static void *__slab_alloc(struct kmem_ca
stat(s, ALLOC_REFILL);

load_freelist:
+ VM_BUG_ON(!page->frozen);
+
object = page->freelist;
if (unlikely(!object))
goto another_slab;
@@ -1833,6 +1835,7 @@ new_slab:
page = get_partial(s, gfpflags, node);
if (page) {
stat(s, ALLOC_FROM_PARTIAL);
+ page->frozen = 1;
load_from_page:
c->node = page_to_nid(page);
c->page = page;
@@ -1855,7 +1858,6 @@ load_from_page:
flush_slab(s, c);

slab_lock(page);
- page->frozen = 1;

goto load_from_page;
}
@@ -2375,6 +2377,7 @@ static void early_kmem_cache_node_alloc(
BUG_ON(!n);
page->freelist = get_freepointer(kmem_cache_node, n);
page->inuse++;
+ page->frozen = 0;
kmem_cache_node->node[node] = n;
#ifdef CONFIG_SLUB_DEBUG
init_object(kmem_cache_node, n, SLUB_RED_ACTIVE);