Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760516AbZAGSmF (ORCPT ); Wed, 7 Jan 2009 13:42:05 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758217AbZAGSl3 (ORCPT ); Wed, 7 Jan 2009 13:41:29 -0500 Received: from e28smtp04.in.ibm.com ([59.145.155.4]:59736 "EHLO e28smtp04.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756354AbZAGSlZ (ORCPT ); Wed, 7 Jan 2009 13:41:25 -0500 From: Balbir Singh To: Andrew Morton Cc: Sudhir Kumar , YAMAMOTO Takashi , Paul Menage , lizf@cn.fujitsu.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, David Rientjes , Pavel Emelianov , Balbir Singh , KAMEZAWA Hiroyuki Date: Thu, 08 Jan 2009 00:11:23 +0530 Message-Id: <20090107184123.18062.81916.sendpatchset@localhost.localdomain> In-Reply-To: <20090107184110.18062.41459.sendpatchset@localhost.localdomain> References: <20090107184110.18062.41459.sendpatchset@localhost.localdomain> Subject: [RFC][PATCH 2/4] Memory controller soft limit interface Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4337 Lines: 150 From: Balbir Singh 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. Signed-off-by: Balbir Singh --- include/linux/res_counter.h | 39 ++++++++++++++++++++++++++++++++++ kernel/res_counter.c | 3 ++ mm/memcontrol.c | 20 +++++++++++++++++ 3 files changed, 62 insertions(+) diff -puN mm/memcontrol.c~memcg-add-soft-limit-interface mm/memcontrol.c --- a/mm/memcontrol.c~memcg-add-soft-limit-interface +++ a/mm/memcontrol.c @@ -1811,6 +1811,20 @@ 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; @@ -2010,6 +2024,12 @@ 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, diff -puN include/linux/res_counter.h~memcg-add-soft-limit-interface include/linux/res_counter.h --- a/include/linux/res_counter.h~memcg-add-soft-limit-interface +++ a/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 +135,28 @@ static inline bool res_counter_limit_che 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() @@ -178,4 +205,16 @@ 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 diff -puN kernel/res_counter.c~memcg-add-soft-limit-interface kernel/res_counter.c --- a/kernel/res_counter.c~memcg-add-soft-limit-interface +++ a/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(); _ -- Balbir -- 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/