From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-f198.google.com (mail-qt0-f198.google.com [209.85.216.198]) by kanga.kvack.org (Postfix) with ESMTP id 1AB0F6B0389 for ; Wed, 22 Feb 2017 10:58:41 -0500 (EST) Received: by mail-qt0-f198.google.com with SMTP id 42so4309520qtn.2 for ; Wed, 22 Feb 2017 07:58:41 -0800 (PST) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com. [148.163.158.5]) by mx.google.com with ESMTPS id w139si1901930iod.132.2017.02.22.07.58.34 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 22 Feb 2017 07:58:34 -0800 (PST) Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v1MFsN5u108929 for ; Wed, 22 Feb 2017 10:58:34 -0500 Received: from e06smtp08.uk.ibm.com (e06smtp08.uk.ibm.com [195.75.94.104]) by mx0a-001b2d01.pphosted.com with ESMTP id 28sau39gyq-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 22 Feb 2017 10:58:33 -0500 Received: from localhost by e06smtp08.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 22 Feb 2017 15:58:31 -0000 From: Laurent Dufour Subject: [PATCH 2/2] mm/cgroup: delay soft limit data allocation Date: Wed, 22 Feb 2017 16:58:11 +0100 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> Message-Id: <1487779091-31381-3-git-send-email-ldufour@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner , Michal Hocko , Vladimir Davydov Cc: cgroups@vger.kernel.org, linux-mm@kvack.org, 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 -- 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