From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with SMTP id 9BFCA6B003D for ; Fri, 27 Mar 2009 00:56:18 -0400 (EDT) Received: from m5.gw.fujitsu.co.jp ([10.0.50.75]) by fgwmail6.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n2R53FJY026233 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Fri, 27 Mar 2009 14:03:15 +0900 Received: from smail (m5 [127.0.0.1]) by outgoing.m5.gw.fujitsu.co.jp (Postfix) with ESMTP id E9B1A45DE52 for ; Fri, 27 Mar 2009 14:03:14 +0900 (JST) Received: from s5.gw.fujitsu.co.jp (s5.gw.fujitsu.co.jp [10.0.50.95]) by m5.gw.fujitsu.co.jp (Postfix) with ESMTP id C95EA45DE51 for ; Fri, 27 Mar 2009 14:03:14 +0900 (JST) Received: from s5.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s5.gw.fujitsu.co.jp (Postfix) with ESMTP id B0AAA1DB803F for ; Fri, 27 Mar 2009 14:03:14 +0900 (JST) Received: from m105.s.css.fujitsu.com (m105.s.css.fujitsu.com [10.249.87.105]) by s5.gw.fujitsu.co.jp (Postfix) with ESMTP id 5BD231DB803C for ; Fri, 27 Mar 2009 14:03:14 +0900 (JST) Date: Fri, 27 Mar 2009 14:01:47 +0900 From: KAMEZAWA Hiroyuki Subject: [RFC][PATCH 1/8] soft limit support in res_counter Message-Id: <20090327140147.aedea657.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20090327135933.789729cb.kamezawa.hiroyu@jp.fujitsu.com> References: <20090327135933.789729cb.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-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "balbir@linux.vnet.ibm.com" , "kosaki.motohiro@jp.fujitsu.com" , "nishimura@mxp.nes.nec.co.jp" List-ID: This is from Balbir's one. -Kame == From: Balbir Singh Changelog v2...v1 1. Add support for res_counter_check_soft_limit_locked. This is used by the hierarchy code. Add an interface to allow get/set of soft limits. Soft limits for memory plus swap controller (memsw) is currently not supported. Resource counters have been enhanced to support soft limits and new type RES_SOFT_LIMIT has been added. Unlike hard limits, soft limits can be directly set and do not need any reclaim or checks before setting them to a newer value. Kamezawa-San raised a question as to whether soft limit should belong to res_counter. Since all resources understand the basic concepts of hard and soft limits, it is justified to add soft limits here. Soft limits are a generic resource usage feature, even file system quotas support soft limits. Signed-off-by: Balbir Singh --- Index: mmotm-2.6.29-Mar23/include/linux/res_counter.h =================================================================== --- mmotm-2.6.29-Mar23.orig/include/linux/res_counter.h +++ mmotm-2.6.29-Mar23/include/linux/res_counter.h @@ -35,6 +35,10 @@ struct res_counter { */ unsigned long long limit; /* + * the limit that usage can be exceed + */ + unsigned long long soft_limit; + /* * the number of unsuccessful attempts to consume the resource */ unsigned long long failcnt; @@ -85,6 +89,7 @@ enum { RES_MAX_USAGE, RES_LIMIT, RES_FAILCNT, + RES_SOFT_LIMIT, }; /* @@ -130,6 +135,36 @@ static inline bool res_counter_limit_che return false; } +static inline bool res_counter_soft_limit_check_locked(struct res_counter *cnt) +{ + if (cnt->usage < cnt->soft_limit) + return true; + + return false; +} + +/** + * Get the difference between the usage and the soft limit + * @cnt: The counter + * + * Returns 0 if usage is less than or equal to soft limit + * The difference between usage and soft limit, otherwise. + */ +static inline unsigned long long +res_counter_soft_limit_excess(struct res_counter *cnt) +{ + unsigned long long excess; + unsigned long flags; + + spin_lock_irqsave(&cnt->lock, flags); + if (cnt->usage <= cnt->soft_limit) + excess = 0; + else + excess = cnt->usage - cnt->soft_limit; + spin_unlock_irqrestore(&cnt->lock, flags); + return excess; +} + /* * Helper function to detect if the cgroup is within it's limit or * not. It's currently called from cgroup_rss_prepare() @@ -145,6 +180,17 @@ static inline bool res_counter_check_und return ret; } +static inline bool res_counter_check_under_soft_limit(struct res_counter *cnt) +{ + bool ret; + unsigned long flags; + + spin_lock_irqsave(&cnt->lock, flags); + ret = res_counter_soft_limit_check_locked(cnt); + spin_unlock_irqrestore(&cnt->lock, flags); + return ret; +} + static inline void res_counter_reset_max(struct res_counter *cnt) { unsigned long flags; @@ -178,4 +224,16 @@ static inline int res_counter_set_limit( return ret; } +static inline int +res_counter_set_soft_limit(struct res_counter *cnt, + unsigned long long soft_limit) +{ + unsigned long flags; + + spin_lock_irqsave(&cnt->lock, flags); + cnt->soft_limit = soft_limit; + spin_unlock_irqrestore(&cnt->lock, flags); + return 0; +} + #endif Index: mmotm-2.6.29-Mar23/kernel/res_counter.c =================================================================== --- mmotm-2.6.29-Mar23.orig/kernel/res_counter.c +++ mmotm-2.6.29-Mar23/kernel/res_counter.c @@ -19,6 +19,7 @@ void res_counter_init(struct res_counter { spin_lock_init(&counter->lock); counter->limit = (unsigned long long)LLONG_MAX; + counter->soft_limit = (unsigned long long)LLONG_MAX; counter->parent = parent; } @@ -101,6 +102,8 @@ res_counter_member(struct res_counter *c return &counter->limit; case RES_FAILCNT: return &counter->failcnt; + case RES_SOFT_LIMIT: + return &counter->soft_limit; }; BUG(); Index: mmotm-2.6.29-Mar23/mm/memcontrol.c =================================================================== --- mmotm-2.6.29-Mar23.orig/mm/memcontrol.c +++ mmotm-2.6.29-Mar23/mm/memcontrol.c @@ -2002,6 +2002,20 @@ static int mem_cgroup_write(struct cgrou else ret = mem_cgroup_resize_memsw_limit(memcg, val); break; + case RES_SOFT_LIMIT: + ret = res_counter_memparse_write_strategy(buffer, &val); + if (ret) + break; + /* + * For memsw, soft limits are hard to implement in terms + * of semantics, for now, we support soft limits for + * control without swap + */ + if (type == _MEM) + ret = res_counter_set_soft_limit(&memcg->res, val); + else + ret = -EINVAL; + break; default: ret = -EINVAL; /* should be BUG() ? */ break; @@ -2251,6 +2265,12 @@ static struct cftype mem_cgroup_files[] .read_u64 = mem_cgroup_read, }, { + .name = "soft_limit_in_bytes", + .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT), + .write_string = mem_cgroup_write, + .read_u64 = mem_cgroup_read, + }, + { .name = "failcnt", .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT), .trigger = mem_cgroup_reset, -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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