3.12-stable review patch. If anyone has any objections, please let me know.
------------------ From: Hugh Dickins <hu...@google.com> commit d8ad30559715ce97afb7d1a93a12fd90e8fff312 upstream. It is surprising that the mem_cgroup iterator can return memcgs which have not yet been fully initialized. By accident (or trial and error?) this appears not to present an actual problem; but it may be better to prevent such surprises, by skipping memcgs not yet online. Signed-off-by: Hugh Dickins <hu...@google.com> Cc: Tejun Heo <t...@kernel.org> Acked-by: Michal Hocko <mho...@suse.cz> Cc: Johannes Weiner <han...@cmpxchg.org> Signed-off-by: Andrew Morton <a...@linux-foundation.org> Signed-off-by: Linus Torvalds <torva...@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- mm/memcontrol.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1081,10 +1081,8 @@ skip_node: * protected by css_get and the tree walk is rcu safe. */ if (next_css) { - struct mem_cgroup *mem = mem_cgroup_from_css(next_css); - - if (css_tryget(&mem->css)) - return mem; + if ((next_css->flags & CSS_ONLINE) && css_tryget(next_css)) + return mem_cgroup_from_css(next_css); else { prev_css = next_css; goto skip_node; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/