From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id 85E0690008E for ; Fri, 15 Apr 2011 16:13:01 -0400 (EDT) Message-Id: <20110415201259.018029060@linux.com> Date: Fri, 15 Apr 2011 15:12:53 -0500 From: Christoph Lameter Subject: [slubllv333num@/21] slub: Do not use frozen page flag but a bit in the page counters References: <20110415201246.096634892@linux.com> Content-Disposition: inline; filename=frozen_field Sender: owner-linux-mm@kvack.org List-ID: To: Pekka Enberg Cc: David Rientjes , Hugh Dickins , Eric Dumazet , "H. Peter Anvin" , Mathieu Desnoyers , linux-mm@kvack.org 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 --- 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; } -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org