Shame on me :-( I wonder why my compiler didn't complain...
The patch fixing this is attached. Andrew, could you please apply it?
Thank you and sorry for the inconvenience.
On 01/10/2014 05:38 AM, kbuild test robot wrote:
> tree: git://git.cmpxchg.org/linux-mmotm.git master
> head: 3fe55fa60ae65a3c8348ae1bfc6fd2e5c3f10654
> commit: f44aea42422dcbc58cd8cc4fc8c564b91a283cef [207/422] memcg: rework memcg_update_kmem_limit synchronization
> config: x86_64-randconfig-c2-0110 (attached as .config)
>
> Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
> http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings
>
> All warnings:
>
> mm/memcontrol.c: In function 'mem_cgroup_css_online':
>>> mm/memcontrol.c:5884:5: warning: 'ret' may be used uninitialized in this function [-Wmaybe-uninitialized]
> if (ret)
> ^
> mm/memcontrol.c:5192:6: note: 'ret' was declared here
> int ret;
> ^
>
> vim +/ret +5884 mm/memcontrol.c
>
> 3c11ecf4 KAMEZAWA Hiroyuki 2010-05-26 5868 return -EINVAL;
> 3c11ecf4 KAMEZAWA Hiroyuki 2010-05-26 5869 }
> c0ff4b85 Raghavendra K T 2011-11-02 5870 memcg->oom_kill_disable = val;
> 4d845ebf KAMEZAWA Hiroyuki 2010-06-29 5871 if (!val)
> c0ff4b85 Raghavendra K T 2011-11-02 5872 memcg_oom_recover(memcg);
> 0999821b Glauber Costa 2013-02-22 5873 mutex_unlock(&memcg_create_mutex);
> 3c11ecf4 KAMEZAWA Hiroyuki 2010-05-26 5874 return 0;
> 3c11ecf4 KAMEZAWA Hiroyuki 2010-05-26 5875 }
> 3c11ecf4 KAMEZAWA Hiroyuki 2010-05-26 5876
> c255a458 Andrew Morton 2012-07-31 5877 #ifdef CONFIG_MEMCG_KMEM
> cbe128e3 Glauber Costa 2012-04-09 5878 static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
> e5671dfa Glauber Costa 2011-12-11 5879 {
> 55007d84 Glauber Costa 2012-12-18 5880 int ret;
> 55007d84 Glauber Costa 2012-12-18 5881
> 2633d7a0 Glauber Costa 2012-12-18 5882 memcg->kmemcg_id = -1;
> 55007d84 Glauber Costa 2012-12-18 5883 ret = memcg_propagate_kmem(memcg);
> 55007d84 Glauber Costa 2012-12-18 @5884 if (ret)
> 55007d84 Glauber Costa 2012-12-18 5885 return ret;
> 2633d7a0 Glauber Costa 2012-12-18 5886
> 1d62e436 Glauber Costa 2012-04-09 5887 return mem_cgroup_sockets_init(memcg, ss);
> 573b400d Michel Lespinasse 2013-04-29 5888 }
> e5671dfa Glauber Costa 2011-12-11 5889
> 10d5ebf4 Li Zefan 2013-07-08 5890 static void memcg_destroy_kmem(struct mem_cgroup *memcg)
> d1a4c0b3 Glauber Costa 2011-12-11 5891 {
> 1d62e436 Glauber Costa 2012-04-09 5892 mem_cgroup_sockets_destroy(memcg);
>
> :::::: The code at line 5884 was first introduced by commit
> :::::: 55007d849759252ddd573aeb36143b947202d509 memcg: allocate memory for memcg caches whenever a new memcg appears
>
> :::::: TO: Glauber Costa <glommer@xxxxxxxxxxxxx>
> :::::: CC: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
>
> ---
> 0-DAY kernel build testing backend Open Source Technology Center
> http://lists.01.org/mailman/listinfo/kbuild Intel Corporation
>From f6c4a5eb38211b79beaa1b571054c9649ca6cb75 Mon Sep 17 00:00:00 2001
From: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx>
Date: Fri, 10 Jan 2014 10:43:20 +0400
Subject: [PATCH] memcg: fix uninitialized var in memcg_propagate_kmem
mm/memcontrol.c: In function 'mem_cgroup_css_online':
mm/memcontrol.c:5884:5: warning: 'ret' may be used uninitialized in this
function [-Wmaybe-uninitialized]
Signed-off-by: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx>
---
mm/memcontrol.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 2a24789..081c58c 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -5227,7 +5227,7 @@ static int memcg_update_kmem_limit(struct mem_cgroup *memcg,
static int memcg_propagate_kmem(struct mem_cgroup *memcg)
{
- int ret;
+ int ret = 0;
struct mem_cgroup *parent = parent_mem_cgroup(memcg);
if (!parent)
--
1.7.1