Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755411AbZIBAhr (ORCPT ); Tue, 1 Sep 2009 20:37:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752408AbZIBAhr (ORCPT ); Tue, 1 Sep 2009 20:37:47 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:55253 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751647AbZIBAhq (ORCPT ); Tue, 1 Sep 2009 20:37:46 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 Date: Wed, 2 Sep 2009 09:35:51 +0900 From: KAMEZAWA Hiroyuki To: KAMEZAWA Hiroyuki Cc: "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "balbir@linux.vnet.ibm.com" , "nishimura@mxp.nes.nec.co.jp" , "akpm@linux-foundation.org" Subject: [mmotm][PATCH 2/2] memcg: reduce calls for soft limit excess Message-Id: <20090902093551.c8b171fb.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20090902093438.eed47a57.kamezawa.hiroyu@jp.fujitsu.com> References: <20090902093438.eed47a57.kamezawa.hiroyu@jp.fujitsu.com> Organization: FUJITSU Co. LTD. X-Mailer: Sylpheed 2.5.0 (GTK+ 2.10.14; i686-pc-mingw32) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3879 Lines: 111 In charge 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. Signed-off-by: KAMEZAWA Hiroyuki --- mm/memcontrol.c | 31 +++++++++++++++---------------- 1 file changed, 15 insertions(+), 16 deletions(-) Index: mmotm-2.6.31-Aug27/mm/memcontrol.c =================================================================== --- mmotm-2.6.31-Aug27.orig/mm/memcontrol.c +++ mmotm-2.6.31-Aug27/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 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); } } @@ -2216,6 +2215,7 @@ 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; @@ -2260,9 +2260,8 @@ unsigned long mem_cgroup_soft_limit_recl __mem_cgroup_largest_soft_limit_node(mctz); } while (next_mz == mz); } - 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. @@ -2271,8 +2270,8 @@ 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 from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/