From: Michal Hocko <mho...@suse.cz>
Kirill has reported the following:
Task in /test killed as a result of limit of /test
memory: usage 10240kB, limit 10240kB, failcnt 51
memory+swap: usage 10240kB, limit 10240kB, failcnt 0
kmem: usage 0kB, limit 18014398509481983kB, failcnt 0
Memory cgroup stats for /test:
BUG: sleeping function called from invalid context at kernel/cpu.c:68
in_atomic(): 1, irqs_disabled(): 0, pid: 66, name: memcg_test
2 locks held by memcg_test/66:
#0: (memcg_oom_lock#2){+.+...}, at: [<ffffffff81131014>]
pagefault_out_of_memory+0x14/0x90
#1: (oom_info_lock){+.+...}, at: [<ffffffff81197b2a>]
mem_cgroup_print_oom_info+0x2a/0x390
CPU: 2 PID: 66 Comm: memcg_test Not tainted 3.14.0-rc1-dirty #745
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS Bochs 01/01/2011
Call Trace:
__might_sleep+0x16a/0x210
get_online_cpus+0x1c/0x60
mem_cgroup_read_stat+0x27/0xb0
mem_cgroup_print_oom_info+0x260/0x390
dump_header+0x88/0x251
? trace_hardirqs_on+0xd/0x10
oom_kill_process+0x258/0x3d0
mem_cgroup_oom_synchronize+0x656/0x6c0
? mem_cgroup_charge_common+0xd0/0xd0
pagefault_out_of_memory+0x14/0x90
mm_fault_error+0x91/0x189
__do_page_fault+0x48e/0x580
do_page_fault+0xe/0x10
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 was introduced by 947b3dd1a84b ("memcg, oom: lock
mem_cgroup_print_oom_info").
Signed-off-by: Michal Hocko <mho...@suse.cz>
Reported-by: "Kirill A. Shutemov" <kirill.shute...@linux.intel.com>
Cc: Johannes Weiner <han...@cmpxchg.org>
Cc: David Rientjes <rient...@google.com>
Signed-off-by: Andrew Morton <a...@linux-foundation.org>
Signed-off-by: Linus Torvalds <torva...@linux-foundation.org>
(cherry picked from commit 08088cb9ac0a9c28d4cf3efa4f6848a9b053ccfd)
Signed-off-by: Vladimir Davydov <vdavy...@parallels.com>
---
mm/memcontrol.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 54bad06b0200..0c617c32d7fa 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1823,7 +1823,7 @@ 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];
@@ -1834,7 +1834,7 @@ 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;
@@ -1903,7 +1903,7 @@ done:
pr_cont("\n");
}
- spin_unlock(&oom_info_lock);
+ mutex_unlock(&oom_info_lock);
}
/*
--
2.1.4
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