From: Christoph Lameter <cl@linux.com>
To: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: David Rientjes <rientjes@google.com>,
Hugh Dickins <hughd@google.com>,
Eric Dumazet <eric.dumazet@gmail.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
linux-mm@kvack.org
Subject: [slubllv333num@/21] slub: Do not use frozen page flag but a bit in the page counters
Date: Fri, 15 Apr 2011 15:12:53 -0500 [thread overview]
Message-ID: <20110415201259.018029060@linux.com> (raw)
In-Reply-To: 20110415201246.096634892@linux.com
[-- Attachment #1: frozen_field --]
[-- Type: text/plain, Size: 3521 bytes --]
Do not use a page flag for the frozen bit. It needs to be part
of the state that is handled with cmpxchg_double(). So use a bit
in the counter struct in the page struct for that purpose.
Also all page start out as frozen pages so set the bit
when the page is allocated.
Signed-off-by: Christoph Lameter <cl@linux.com>
---
include/linux/mm_types.h | 5 +++--
include/linux/page-flags.h | 2 --
mm/slub.c | 12 ++++++------
3 files changed, 9 insertions(+), 10 deletions(-)
Index: linux-2.6/include/linux/mm_types.h
===================================================================
--- linux-2.6.orig/include/linux/mm_types.h 2011-04-15 12:54:32.000000000 -0500
+++ linux-2.6/include/linux/mm_types.h 2011-04-15 13:14:36.000000000 -0500
@@ -41,8 +41,9 @@ struct page {
* & limit reverse map searches.
*/
struct { /* SLUB */
- u16 inuse;
- u16 objects;
+ unsigned inuse:16;
+ unsigned objects:15;
+ unsigned frozen:1;
};
};
union {
Index: linux-2.6/include/linux/page-flags.h
===================================================================
--- linux-2.6.orig/include/linux/page-flags.h 2011-04-15 12:54:32.000000000 -0500
+++ linux-2.6/include/linux/page-flags.h 2011-04-15 13:14:36.000000000 -0500
@@ -212,8 +212,6 @@ PAGEFLAG(SwapBacked, swapbacked) __CLEAR
__PAGEFLAG(SlobFree, slob_free)
-__PAGEFLAG(SlubFrozen, slub_frozen)
-
/*
* Private page markings that may be used by the filesystem that owns the page
* for its own purposes.
Index: linux-2.6/mm/slub.c
===================================================================
--- linux-2.6.orig/mm/slub.c 2011-04-15 13:11:25.000000000 -0500
+++ linux-2.6/mm/slub.c 2011-04-15 13:14:36.000000000 -0500
@@ -166,7 +166,7 @@ static inline int kmem_cache_debug(struc
#define OO_SHIFT 16
#define OO_MASK ((1 << OO_SHIFT) - 1)
-#define MAX_OBJS_PER_PAGE 65535 /* since page.objects is u16 */
+#define MAX_OBJS_PER_PAGE 32767 /* since page.objects is u15 */
/* Internal SLUB flags */
#define __OBJECT_POISON 0x80000000UL /* Poison object */
@@ -1013,7 +1013,7 @@ static noinline int free_debug_processin
}
/* Special debug activities for freeing objects */
- if (!PageSlubFrozen(page) && !page->freelist)
+ if (!page->frozen && !page->freelist)
remove_full(s, page);
if (s->flags & SLAB_STORE_USER)
set_track(s, object, TRACK_FREE, addr);
@@ -1402,7 +1402,7 @@ static inline int lock_and_freeze_slab(s
{
if (slab_trylock(page)) {
__remove_partial(n, page);
- __SetPageSlubFrozen(page);
+ page->frozen = 1;
return 1;
}
return 0;
@@ -1516,7 +1516,7 @@ static void unfreeze_slab(struct kmem_ca
{
struct kmem_cache_node *n = get_node(s, page_to_nid(page));
- __ClearPageSlubFrozen(page);
+ page->frozen = 0;
if (page->inuse) {
if (page->freelist) {
@@ -1867,7 +1867,7 @@ load_from_page:
flush_slab(s, c);
slab_lock(page);
- __SetPageSlubFrozen(page);
+ page->frozen = 1;
goto load_from_page;
}
@@ -2081,7 +2081,7 @@ static void __slab_free(struct kmem_cach
page->freelist = object;
page->inuse--;
- if (unlikely(PageSlubFrozen(page))) {
+ if (unlikely(page->frozen)) {
stat(s, FREE_FROZEN);
goto out_unlock;
}
--
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next prev parent reply other threads:[~2011-04-15 20:13 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-15 20:12 [slubllv333num@/21] SLUB: Lockless freelists for objects V3 Christoph Lameter
2011-04-15 20:12 ` [slubllv333num@/21] slub: Use NUMA_NO_NODE in get_partial Christoph Lameter
2011-04-15 20:12 ` [slubllv333num@/21] slub: get_map() function to establish map of free objects in a slab Christoph Lameter
2011-04-15 20:12 ` [slubllv333num@/21] slub: Eliminate repeated use of c->page through a new page variable Christoph Lameter
2011-04-15 20:12 ` [slubllv333num@/21] slub: Move node determination out of hotpath Christoph Lameter
2011-04-15 20:12 ` [slubllv333num@/21] slub: Move debug handlign in __slab_free Christoph Lameter
2011-04-15 20:12 ` [slubllv333num@/21] slub: Per object NUMA support Christoph Lameter
2011-04-15 20:12 ` Christoph Lameter [this message]
2011-04-15 20:12 ` [slubllv333num@/21] slub: Move page->frozen handling near where the page->freelist handling occurs Christoph Lameter
2011-04-15 20:12 ` [slubllv333num@/21] x86: Add support for cmpxchg_double Christoph Lameter
2011-04-15 20:12 ` [slubllv333num@/21] mm: Rearrange struct page Christoph Lameter
2011-04-15 20:12 ` [slubllv333num@/21] slub: Add cmpxchg_double_slab() Christoph Lameter
2011-04-15 20:12 ` [slubllv333num@/21] slub: explicit list_lock taking Christoph Lameter
2011-04-15 20:12 ` [slubllv333num@/21] slub: Pass kmem_cache struct to lock and freeze slab Christoph Lameter
2011-04-15 20:13 ` [slubllv333num@/21] slub: Rework allocator fastpaths Christoph Lameter
2011-04-15 20:13 ` [slubllv333num@/21] slub: Invert locking and avoid slab lock Christoph Lameter
2011-04-15 20:13 ` [slubllv333num@/21] slub: Disable interrupts in free_debug processing Christoph Lameter
2011-04-15 20:13 ` [slubllv333num@/21] slub: Avoid disabling interrupts in free slowpath Christoph Lameter
2011-04-15 20:13 ` [slubllv333num@/21] slub: Get rid of the another_slab label Christoph Lameter
2011-04-15 20:13 ` [slubllv333num@/21] slub: fast release on full slab Christoph Lameter
2011-04-15 20:13 ` [slubllv333num@/21] slub: Not necessary to check for empty slab on load_freelist Christoph Lameter
2011-04-15 20:13 ` [slubllv333num@/21] slub: update statistics for cmpxchg handling Christoph Lameter
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