From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from d23relay03.au.ibm.com (d23relay03.au.ibm.com [202.81.18.234]) by e23smtp02.au.ibm.com (8.13.1/8.13.1) with ESMTP id mAG8EDGZ017423 for ; Sun, 16 Nov 2008 19:14:13 +1100 Received: from d23av02.au.ibm.com (d23av02.au.ibm.com [9.190.235.138]) by d23relay03.au.ibm.com (8.13.8/8.13.8/NCO v9.1) with ESMTP id mAG8BMkb5103812 for ; Sun, 16 Nov 2008 19:11:26 +1100 Received: from d23av02.au.ibm.com (loopback [127.0.0.1]) by d23av02.au.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id mAG8BA96021906 for ; Sun, 16 Nov 2008 19:11:10 +1100 From: Balbir Singh Date: Sun, 16 Nov 2008 13:41:05 +0530 Message-Id: <20081116081105.25166.54820.sendpatchset@balbir-laptop> In-Reply-To: <20081116081034.25166.7586.sendpatchset@balbir-laptop> References: <20081116081034.25166.7586.sendpatchset@balbir-laptop> Subject: [mm] [PATCH 4/4] Memory cgroup hierarchy feature selector (v4) Sender: owner-linux-mm@kvack.org Return-Path: To: linux-mm@kvack.org Cc: YAMAMOTO Takashi , Paul Menage , lizf@cn.fujitsu.com, linux-kernel@vger.kernel.org, Nick Piggin , David Rientjes , Pavel Emelianov , Dhaval Giani , Balbir Singh , Andrew Morton , KAMEZAWA Hiroyuki List-ID: Don't enable multiple hierarchy support by default. This patch introduces a features element that can be set to enable the nested depth hierarchy feature. This feature can only be enabled when the cgroup for which the feature this is enabled, has no children. Signed-off-by: Balbir Singh --- mm/memcontrol.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 57 insertions(+), 4 deletions(-) diff -puN mm/memcontrol.c~memcg-add-hierarchy-selector mm/memcontrol.c --- linux-2.6.28-rc4/mm/memcontrol.c~memcg-add-hierarchy-selector 2008-11-16 13:19:33.000000000 +0530 +++ linux-2.6.28-rc4-balbir/mm/memcontrol.c 2008-11-16 13:19:33.000000000 +0530 @@ -148,6 +148,10 @@ struct mem_cgroup { * reclaimed from. Protected by cgroup_lock() */ struct mem_cgroup *last_scanned_child; + /* + * Should the accounting and control be hierarchical, per subtree? + */ + unsigned long use_hierarchy; int obsolete; atomic_t refcnt; @@ -1527,6 +1531,44 @@ int mem_cgroup_force_empty_write(struct } +static u64 mem_cgroup_hierarchy_read(struct cgroup *cont, struct cftype *cft) +{ + return mem_cgroup_from_cont(cont)->use_hierarchy; +} + +static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft, + u64 val) +{ + int retval = 0; + struct mem_cgroup *mem = mem_cgroup_from_cont(cont); + struct cgroup *parent = cont->parent; + struct mem_cgroup *parent_mem = NULL; + + if (parent) + parent_mem = mem_cgroup_from_cont(parent); + + cgroup_lock(); + /* + * If parent's use_hiearchy is set, we can't make any modifications + * in the child subtrees. If it is unset, then the change can + * occur, provided the current cgroup has no children. + * + * For the root cgroup, parent_mem is NULL, we allow value to be + * set if there are no children. + */ + if (!parent_mem || (!parent_mem->use_hierarchy && + (val == 1 || val == 0))) { + if (list_empty(&cont->children)) + mem->use_hierarchy = val; + else + retval = -EBUSY; + } else + retval = -EINVAL; + cgroup_unlock(); + + return retval; +} + static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft) { struct mem_cgroup *mem = mem_cgroup_from_cont(cont); @@ -1690,6 +1732,11 @@ static struct cftype mem_cgroup_files[] .name = "force_empty", .trigger = mem_cgroup_force_empty_write, }, + { + .name = "use_hierarchy", + .write_u64 = mem_cgroup_hierarchy_write, + .read_u64 = mem_cgroup_hierarchy_read, + }, }; #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP @@ -1865,12 +1912,18 @@ mem_cgroup_create(struct cgroup_subsys * if (cont->parent == NULL) { enable_swap_cgroup(); parent = NULL; - } else + } else { parent = mem_cgroup_from_cont(cont->parent); + mem->use_hierarchy = parent->use_hierarchy; + } - res_counter_init(&mem->res, parent ? &parent->res : NULL); - res_counter_init(&mem->memsw, parent ? &parent->memsw : NULL); - + if (parent && parent->use_hierarchy) { + res_counter_init(&mem->res, &parent->res); + res_counter_init(&mem->memsw, &parent->memsw); + } else { + res_counter_init(&mem->res, NULL); + res_counter_init(&mem->memsw, NULL); + } mem->last_scanned_child = NULL; _ -- Balbir -- 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