From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wg0-f53.google.com (mail-wg0-f53.google.com [74.125.82.53]) by kanga.kvack.org (Postfix) with ESMTP id 26CE96B0037 for ; Mon, 10 Feb 2014 08:48:13 -0500 (EST) Received: by mail-wg0-f53.google.com with SMTP id y10so4221630wgg.20 for ; Mon, 10 Feb 2014 05:48:12 -0800 (PST) Received: from mx2.suse.de (cantor2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id c8si6830559wix.16.2014.02.10.05.48.10 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Mon, 10 Feb 2014 05:48:11 -0800 (PST) From: Michal Hocko Subject: [PATCH] memcg: change oom_info_lock to mutex Date: Mon, 10 Feb 2014 14:48:02 +0100 Message-Id: <1392040082-14303-1-git-send-email-mhocko@suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Johannes Weiner , "Kirill A. Shutemov" , LKML , linux-mm@kvack.org Kirill has reported the following: [ 2.386563] Task in /test killed as a result of limit of /test [ 2.387326] memory: usage 10240kB, limit 10240kB, failcnt 51 [ 2.388098] memory+swap: usage 10240kB, limit 10240kB, failcnt 0 [ 2.388861] kmem: usage 0kB, limit 18014398509481983kB, failcnt 0 [ 2.389640] Memory cgroup stats for /test: [ 2.390178] BUG: sleeping function called from invalid context at /home/space/kas/git/public/linux/kernel/cpu.c:68 [ 2.391516] in_atomic(): 1, irqs_disabled(): 0, pid: 66, name: memcg_test [ 2.392416] 2 locks held by memcg_test/66: [ 2.392945] #0: (memcg_oom_lock#2){+.+...}, at: [] pagefault_out_of_memory+0x14/0x90 [ 2.394233] #1: (oom_info_lock){+.+...}, at: [] mem_cgroup_print_oom_info+0x2a/0x390 [ 2.395496] CPU: 2 PID: 66 Comm: memcg_test Not tainted 3.14.0-rc1-dirty #745 [ 2.396536] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS Bochs 01/01/2011 [ 2.397540] ffffffff81a3cc90 ffff88081d26dba0 ffffffff81776ea3 0000000000000000 [ 2.398541] ffff88081d26dbc8 ffffffff8108418a 0000000000000000 ffff88081d15c000 [ 2.399533] 0000000000000000 ffff88081d26dbd8 ffffffff8104f6bc ffff88081d26dc10 [ 2.400588] Call Trace: [ 2.400908] [] dump_stack+0x4d/0x66 [ 2.401578] [] __might_sleep+0x16a/0x210 [ 2.402295] [] get_online_cpus+0x1c/0x60 [ 2.403005] [] mem_cgroup_read_stat+0x27/0xb0 [ 2.403769] [] mem_cgroup_print_oom_info+0x260/0x390 [ 2.404653] [] dump_header+0x88/0x251 [ 2.405342] [] ? trace_hardirqs_on+0xd/0x10 [ 2.406098] [] oom_kill_process+0x258/0x3d0 [ 2.406833] [] mem_cgroup_oom_synchronize+0x656/0x6c0 [ 2.407674] [] ? mem_cgroup_charge_common+0xd0/0xd0 [ 2.408553] [] pagefault_out_of_memory+0x14/0x90 [ 2.409354] [] mm_fault_error+0x91/0x189 [ 2.410069] [] __do_page_fault+0x48e/0x580 [ 2.410791] [] ? local_clock+0x16/0x30 [ 2.411467] [] ? trace_hardirqs_on+0xd/0x10 [ 2.412248] [] ? _raw_spin_unlock_irq+0x2c/0x40 [ 2.413039] [] ? finish_task_switch+0x7b/0x100 [ 2.413821] [] ? trace_hardirqs_off_thunk+0x3a/0x3c [ 2.414652] [] do_page_fault+0xe/0x10 [ 2.415330] [] page_fault+0x22/0x30 which complains that mem_cgroup_read_stat cannot be called from an atomic context but mem_cgroup_print_oom_info takes a spinlock. Change oom_info_lock to a mutex. This has been introduced by 947b3dd1a84b (memcg, oom: lock mem_cgroup_print_oom_info). Reported-by: "Kirill A. Shutemov" Signed-off-by: Michal Hocko --- mm/memcontrol.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 19d5d4274e22..55e6731ebcd5 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1687,7 +1687,7 @@ void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p) * protects memcg_name and makes sure that parallel ooms do not * interleave */ - static DEFINE_SPINLOCK(oom_info_lock); + static DEFINE_MUTEX(oom_info_lock); struct cgroup *task_cgrp; struct cgroup *mem_cgrp; static char memcg_name[PATH_MAX]; @@ -1698,7 +1698,7 @@ void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p) if (!p) return; - spin_lock(&oom_info_lock); + mutex_lock(&oom_info_lock); rcu_read_lock(); mem_cgrp = memcg->css.cgroup; @@ -1767,7 +1767,7 @@ done: pr_cont("\n"); } - spin_unlock(&oom_info_lock); + mutex_unlock(&oom_info_lock); } /* -- 1.9.rc1 -- 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