From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754809AbdBVP7Z (ORCPT ); Wed, 22 Feb 2017 10:59:25 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:45356 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932361AbdBVP6m (ORCPT ); Wed, 22 Feb 2017 10:58:42 -0500 From: Laurent Dufour To: Johannes Weiner , Michal Hocko , Vladimir Davydov Cc: cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/2] mm/cgroup: delay soft limit data allocation Date: Wed, 22 Feb 2017 16:58:11 +0100 X-Mailer: git-send-email 2.7.4 In-Reply-To: <1487779091-31381-1-git-send-email-ldufour@linux.vnet.ibm.com> References: <1487779091-31381-1-git-send-email-ldufour@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 17022215-0032-0000-0000-00000722E67E X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17022215-0033-0000-0000-000023870727 Message-Id: <1487779091-31381-3-git-send-email-ldufour@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-02-22_10:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1612050000 definitions=main-1702220150 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Until a soft limit is set to a cgroup, the soft limit data are useless so delay this allocation when a limit is set. Suggested-by: Michal Hocko Signed-off-by: Laurent Dufour --- mm/memcontrol.c | 52 +++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 39 insertions(+), 13 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 228ac44f77e1..bc2e6ab69c0c 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -142,6 +142,8 @@ struct mem_cgroup_tree { struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES]; }; +static DEFINE_MUTEX(soft_limit_mutex); +static bool soft_limit_initialized; static struct mem_cgroup_tree soft_limit_tree __read_mostly; /* for OOM */ @@ -381,6 +383,36 @@ mem_cgroup_page_nodeinfo(struct mem_cgroup *memcg, struct page *page) return memcg->nodeinfo[nid]; } +static void soft_limit_initialize(void) +{ + int node; + + mutex_lock(&soft_limit_mutex); + if (soft_limit_initialized) + goto bail; + + for_each_node(node) { + struct mem_cgroup_tree_per_node *rtpn; + + rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, + node_online(node) ? node : NUMA_NO_NODE); + /* Best effort, but should we warn if allocation failed */ + if (rtpn) { + rtpn->rb_root = RB_ROOT; + spin_lock_init(&rtpn->lock); + /* + * We don't want the compiler to set rb_tree_per_node + * before rb_root and lock are initialized. + */ + WRITE_ONCE(soft_limit_tree.rb_tree_per_node[node], + rtpn); + } + } + soft_limit_initialized = true; +bail: + mutex_unlock(&soft_limit_mutex); +} + static struct mem_cgroup_tree_per_node * soft_limit_tree_node(int nid) { @@ -465,6 +497,8 @@ static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page) struct mem_cgroup_tree_per_node *mctz; mctz = soft_limit_tree_from_page(page); + if (!mctz) + return; /* * Necessary to update all ancestors when hierarchy is used. * because their event counter is not touched. @@ -502,7 +536,8 @@ static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg) for_each_node(nid) { mz = mem_cgroup_nodeinfo(memcg, nid); mctz = soft_limit_tree_node(nid); - mem_cgroup_remove_exceeded(mz, mctz); + if (mctz) + mem_cgroup_remove_exceeded(mz, mctz); } } @@ -3000,6 +3035,8 @@ static ssize_t mem_cgroup_write(struct kernfs_open_file *of, } break; case RES_SOFT_LIMIT: + if (!soft_limit_initialized) + soft_limit_initialize(); memcg->soft_limit = nr_pages; ret = 0; break; @@ -5774,7 +5811,7 @@ __setup("cgroup.memory=", cgroup_memory); */ static int __init mem_cgroup_init(void) { - int cpu, node; + int cpu; #ifndef CONFIG_SLOB /* @@ -5794,17 +5831,6 @@ static int __init mem_cgroup_init(void) INIT_WORK(&per_cpu_ptr(&memcg_stock, cpu)->work, drain_local_stock); - for_each_node(node) { - struct mem_cgroup_tree_per_node *rtpn; - - rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, - node_online(node) ? node : NUMA_NO_NODE); - - rtpn->rb_root = RB_ROOT; - spin_lock_init(&rtpn->lock); - soft_limit_tree.rb_tree_per_node[node] = rtpn; - } - return 0; } subsys_initcall(mem_cgroup_init); -- 2.7.4