From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with SMTP id 91643900137 for ; Mon, 29 Aug 2011 21:52:08 -0400 (EDT) Subject: [patch 2/2]slub: explicitly document position of inserting slab to partial list From: Shaohua Li Content-Type: text/plain; charset="UTF-8" Date: Tue, 30 Aug 2011 09:54:12 +0800 Message-ID: <1314669252.29510.49.camel@sli10-conroe> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Christoph Lameter , "penberg@kernel.org" , "Shi, Alex" , "Chen, Tim C" , linux-mm Adding slab to partial list head/tail is sensitive to performance. Using 0/1 can easily cause typo. So explicitly uses DEACTIVATE_TO_TAIL/DEACTIVATE_TO_HEAD to document it to avoid we get it wrong. Signed-off-by: Shaohua Li Signed-off-by: Shaohua Li Acked-by: Christoph Lameter --- mm/slub.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) Index: linux/mm/slub.c =================================================================== --- linux.orig/mm/slub.c 2011-08-30 09:45:03.000000000 +0800 +++ linux/mm/slub.c 2011-08-30 09:45:45.000000000 +0800 @@ -1534,7 +1534,7 @@ static inline void add_partial(struct km struct page *page, int tail) { n->nr_partial++; - if (tail) + if (tail == DEACTIVATE_TO_TAIL) list_add_tail(&page->lru, &n->partial); else list_add(&page->lru, &n->partial); @@ -1781,13 +1781,13 @@ static void deactivate_slab(struct kmem_ enum slab_modes l = M_NONE, m = M_NONE; void *freelist; void *nextfree; - int tail = 0; + int tail = DEACTIVATE_TO_HEAD; struct page new; struct page old; if (page->freelist) { stat(s, DEACTIVATE_REMOTE_FREES); - tail = 1; + tail = DEACTIVATE_TO_TAIL; } c->tid = next_tid(c->tid); @@ -1893,7 +1893,7 @@ redo: if (m == M_PARTIAL) { add_partial(n, page, tail); - stat(s, tail ? DEACTIVATE_TO_TAIL : DEACTIVATE_TO_HEAD); + stat(s, tail); } else if (m == M_FULL) { @@ -2382,7 +2382,7 @@ static void __slab_free(struct kmem_cach * partial list tail so it will not be used * immediately. */ - add_partial(n, page, 1); + add_partial(n, page, DEACTIVATE_TO_TAIL); stat(s, FREE_ADD_PARTIAL); } } @@ -2700,7 +2700,7 @@ static void early_kmem_cache_node_alloc( init_kmem_cache_node(n, kmem_cache_node); inc_slabs_node(kmem_cache_node, node, page->objects); - add_partial(n, page, 0); + add_partial(n, page, DEACTIVATE_TO_HEAD); } static void free_kmem_cache_nodes(struct kmem_cache *s) -- 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