| Message ID | 20200930095336.21323-1-linmiaohe@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3] mm: memcontrol: reword obsolete comment of mem_cgroup_unmark_under_oom() | expand |
On Wed 30-09-20 05:53:36, Miaohe Lin wrote: > Since commit 79dfdaccd1d5 ("memcg: make oom_lock 0 and 1 based rather than > counter"), the mem_cgroup_unmark_under_oom() is added and the comment of > the mem_cgroup_oom_unlock() is moved here. But this comment make no sense > here because mem_cgroup_oom_lock() does not operate on under_oom field. So > we reword the comment as this would be helpful. > [Thanks Michal Hocko for rewording this comment.] > > Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> > Cc: Johannes Weiner <hannes@cmpxchg.org> > Cc: Michal Hocko <mhocko@kernel.org> > Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Thanks! > --- > mm/memcontrol.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 6877c765b8d0..4f0c14cb8690 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -1817,8 +1817,8 @@ static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg) > struct mem_cgroup *iter; > > /* > - * When a new child is created while the hierarchy is under oom, > - * mem_cgroup_oom_lock() may not be called. Watch for underflow. > + * Be careful about under_oom underflows becase a child memcg > + * could have been added after mem_cgroup_mark_under_oom. > */ > spin_lock(&memcg_oom_lock); > for_each_mem_cgroup_tree(iter, memcg) > -- > 2.19.1
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 6877c765b8d0..4f0c14cb8690 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1817,8 +1817,8 @@ static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg) struct mem_cgroup *iter; /* - * When a new child is created while the hierarchy is under oom, - * mem_cgroup_oom_lock() may not be called. Watch for underflow. + * Be careful about under_oom underflows becase a child memcg + * could have been added after mem_cgroup_mark_under_oom. */ spin_lock(&memcg_oom_lock); for_each_mem_cgroup_tree(iter, memcg)
Since commit 79dfdaccd1d5 ("memcg: make oom_lock 0 and 1 based rather than counter"), the mem_cgroup_unmark_under_oom() is added and the comment of the mem_cgroup_oom_unlock() is moved here. But this comment make no sense here because mem_cgroup_oom_lock() does not operate on under_oom field. So we reword the comment as this would be helpful. [Thanks Michal Hocko for rewording this comment.] Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> --- mm/memcontrol.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)