Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753980AbYKPIM5 (ORCPT ); Sun, 16 Nov 2008 03:12:57 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752100AbYKPIMj (ORCPT ); Sun, 16 Nov 2008 03:12:39 -0500 Received: from E23SMTP02.au.ibm.com ([202.81.18.163]:39420 "EHLO e23smtp02.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752011AbYKPIMi (ORCPT ); Sun, 16 Nov 2008 03:12:38 -0500 From: Balbir Singh 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 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: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3447 Lines: 115 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 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/