On Tue, 13 Dec 2011 17:00:12 -0800
Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
> On Mon, 12 Dec 2011 15:09:35 +0100
> Michal Hocko <mhocko@xxxxxxx> wrote:
>
> > And a follow up patch for the proper clean up:
> > ---
> > >From 4b9f5a1e88496af9f336d1ef37cfdf3754a3ba48 Mon Sep 17 00:00:00 2001
> > From: Michal Hocko <mhocko@xxxxxxx>
> > Date: Mon, 12 Dec 2011 15:04:18 +0100
> > Subject: [PATCH] memcg: clean up soft_limit_tree properly
> >
> > If we are not able to allocate tree nodes for all NUMA nodes then we
> > should better clean up those that were allocated otherwise we will leak
> > a memory.
> >
> > Signed-off-by: Michal Hocko <mhocko@xxxxxxx>
> > ---
> > mm/memcontrol.c | 12 +++++++++++-
> > 1 files changed, 11 insertions(+), 1 deletions(-)
> >
> > diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> > index 6aff93c..838d812 100644
> > --- a/mm/memcontrol.c
> > +++ b/mm/memcontrol.c
> > @@ -4874,7 +4874,7 @@ static int mem_cgroup_soft_limit_tree_init(void)
> > tmp = -1;
> > rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp);
> > if (!rtpn)
> > - return 1;
> > + goto err_cleanup;
> >
> > soft_limit_tree.rb_tree_per_node[node] = rtpn;
> >
> > @@ -4885,6 +4885,16 @@ static int mem_cgroup_soft_limit_tree_init(void)
> > }
> > }
> > return 0;
> > +
> > +err_cleanup:
> > + for_each_node_state(node, N_POSSIBLE) {
> > + if (!soft_limit_tree.rb_tree_per_node[node])
> > + break;
> > + kfree(soft_limit_tree.rb_tree_per_node[node]);
> > + soft_limit_tree.rb_tree_per_node[node] = NULL;
> > + }
> > + return 1;
> > +
> > }
>
> afacit the kernel never frees the soft_limit_tree.rb_tree_per_node[]
> entries on the mem_cgroup_destroy() path. Bug?
>
soft_limit_tree.rb_tree_per_node[] is a global object and allocated once
at creating root cgroup.
Nodes of rb_tree for a memcg are contained in struct mem_cgroup_per_zone
and it's freed at mem_cgroup_destroy().
Thanks,
-Kame
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>