On Tue 04-02-14 17:05:21, Michal Hocko wrote: > On Tue 04-02-14 10:55:08, Johannes Weiner wrote: > > On Tue, Feb 04, 2014 at 02:28:55PM +0100, Michal Hocko wrote: > > > Johannes Weiner has pointed out that __mem_cgroup_try_charge duplicates > > > try_get_mem_cgroup_from_mm for charges which came without a memcg. The > > > only reason seems to be a tiny optimization when css_tryget is not > > > called if the charge can be consumed from the stock. Nevertheless > > > css_tryget is very cheap since it has been reworked to use per-cpu > > > counting so this optimization doesn't give us anything these days. > > > > > > So let's drop the code duplication so that the code is more readable. > > > While we are at it also remove a very confusing comment in > > > try_get_mem_cgroup_from_mm. > > > > > > Signed-off-by: Michal Hocko <mhocko@xxxxxxx> > > > --- > > > mm/memcontrol.c | 49 ++++++++----------------------------------------- > > > 1 file changed, 8 insertions(+), 41 deletions(-) > > > > > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > > > index 53385cd4e6f0..042e4ff36c05 100644 > > > --- a/mm/memcontrol.c > > > +++ b/mm/memcontrol.c > > > @@ -1081,11 +1081,7 @@ struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm) > > > > > > if (!mm) > > > return NULL; > > > > While you're at it, this check also seems unnecessary. > > Yes, it will be removed in a later patch. I wanted to have it in a > separate patch for a better bisectability just in case I have really > missed mm-might-by-NULL case. Ohh, I have mixed that with the other mm check. You are right we can remove this one as well. Thanks and sorry for confusion! -- Michal Hocko SUSE Labs -- 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/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>