From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with SMTP id CC3666B0085 for ; Wed, 9 Sep 2009 04:43:55 -0400 (EDT) Received: from m1.gw.fujitsu.co.jp ([10.0.50.71]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n898hwsi029046 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Wed, 9 Sep 2009 17:43:58 +0900 Received: from smail (m1 [127.0.0.1]) by outgoing.m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 16C1F45DE59 for ; Wed, 9 Sep 2009 17:43:58 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (s1.gw.fujitsu.co.jp [10.0.50.91]) by m1.gw.fujitsu.co.jp (Postfix) with ESMTP id DDC5045DE53 for ; Wed, 9 Sep 2009 17:43:57 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id C0784E0800B for ; Wed, 9 Sep 2009 17:43:57 +0900 (JST) Received: from m108.s.css.fujitsu.com (m108.s.css.fujitsu.com [10.249.87.108]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id 69ACAE08008 for ; Wed, 9 Sep 2009 17:43:57 +0900 (JST) Date: Wed, 9 Sep 2009 17:41:59 +0900 From: KAMEZAWA Hiroyuki Subject: [RFC][PATCH 2/4][mmotm] clean up charge path of softlimit Message-Id: <20090909174159.1759aee5.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20090909173903.afc86d85.kamezawa.hiroyu@jp.fujitsu.com> References: <20090909173903.afc86d85.kamezawa.hiroyu@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: "linux-mm@kvack.org" , "balbir@linux.vnet.ibm.com" , "nishimura@mxp.nes.nec.co.jp" List-ID: In charge/uncharge/reclaim path, usage_in_excess is calculated repeatedly and it takes res_counter's spin_lock every time. This patch removes unnecessary calls for res_count_soft_limit_excess. Changelog: - fixed description. - fixed unsigned long to be unsigned long long (Thanks, Nishimura) Reviewed-by: Daisuke Nishimura Signed-off-by: KAMEZAWA Hiroyuki --- mm/memcontrol.c | 31 +++++++++++++++---------------- 1 file changed, 15 insertions(+), 16 deletions(-) Index: mmotm-2.6.31-Sep3/mm/memcontrol.c =================================================================== --- mmotm-2.6.31-Sep3.orig/mm/memcontrol.c +++ mmotm-2.6.31-Sep3/mm/memcontrol.c @@ -313,7 +313,8 @@ soft_limit_tree_from_page(struct page *p static void __mem_cgroup_insert_exceeded(struct mem_cgroup *mem, struct mem_cgroup_per_zone *mz, - struct mem_cgroup_tree_per_zone *mctz) + struct mem_cgroup_tree_per_zone *mctz, + unsigned long long new_usage_in_excess) { struct rb_node **p = &mctz->rb_root.rb_node; struct rb_node *parent = NULL; @@ -322,7 +323,9 @@ __mem_cgroup_insert_exceeded(struct mem_ if (mz->on_tree) return; - mz->usage_in_excess = res_counter_soft_limit_excess(&mem->res); + mz->usage_in_excess = new_usage_in_excess; + if (!mz->usage_in_excess) + return; while (*p) { parent = *p; mz_node = rb_entry(parent, struct mem_cgroup_per_zone, @@ -382,7 +385,7 @@ static bool mem_cgroup_soft_limit_check( static void mem_cgroup_update_tree(struct mem_cgroup *mem, struct page *page) { - unsigned long long new_usage_in_excess; + unsigned long long excess; struct mem_cgroup_per_zone *mz; struct mem_cgroup_tree_per_zone *mctz; int nid = page_to_nid(page); @@ -395,25 +398,21 @@ static void mem_cgroup_update_tree(struc */ for (; mem; mem = parent_mem_cgroup(mem)) { mz = mem_cgroup_zoneinfo(mem, nid, zid); - new_usage_in_excess = - res_counter_soft_limit_excess(&mem->res); + excess = res_counter_soft_limit_excess(&mem->res); /* * We have to update the tree if mz is on RB-tree or * mem is over its softlimit. */ - if (new_usage_in_excess || mz->on_tree) { + if (excess || mz->on_tree) { spin_lock(&mctz->lock); /* if on-tree, remove it */ if (mz->on_tree) __mem_cgroup_remove_exceeded(mem, mz, mctz); /* - * if over soft limit, insert again. mz->usage_in_excess - * will be updated properly. + * Insert again. mz->usage_in_excess will be updated. + * If excess is 0, no tree ops. */ - if (new_usage_in_excess) - __mem_cgroup_insert_exceeded(mem, mz, mctz); - else - mz->usage_in_excess = 0; + __mem_cgroup_insert_exceeded(mem, mz, mctz, excess); spin_unlock(&mctz->lock); } } @@ -2220,6 +2219,7 @@ unsigned long mem_cgroup_soft_limit_recl unsigned long reclaimed; int loop = 0; struct mem_cgroup_tree_per_zone *mctz; + unsigned long long excess; if (order > 0) return 0; @@ -2269,9 +2269,8 @@ unsigned long mem_cgroup_soft_limit_recl break; } while (1); } - mz->usage_in_excess = - res_counter_soft_limit_excess(&mz->mem->res); __mem_cgroup_remove_exceeded(mz->mem, mz, mctz); + excess = res_counter_soft_limit_excess(&mz->mem->res); /* * One school of thought says that we should not add * back the node to the tree if reclaim returns 0. @@ -2280,8 +2279,8 @@ unsigned long mem_cgroup_soft_limit_recl * memory to reclaim from. Consider this as a longer * term TODO. */ - if (mz->usage_in_excess) - __mem_cgroup_insert_exceeded(mz->mem, mz, mctz); + /* If excess == 0, no tree ops */ + __mem_cgroup_insert_exceeded(mz->mem, mz, mctz, excess); spin_unlock(&mctz->lock); css_put(&mz->mem->css); loop++; -- 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/ . Don't email: email@kvack.org