Re: [patch 1/3] mm: memcontrol: remove bogus NULL check after mem_cgroup_from_task()

Vladimir Davydov
2014-10-24T14:41:01Z

On Fri, Oct 24, 2014 at 09:49:47AM -0400, Johannes Weiner wrote:
> That function acts like a typecast - unless NULL is passed in, no NULL
> can come out. task_in_mem_cgroup() callers don't pass NULL tasks.
>
> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>

Reviewed-by: Vladimir Davydov <vdavydov@parallels.com>

> ---
> mm/memcontrol.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 23cf27cca370..bdf8520979cf 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -1335,7 +1335,7 @@ static bool mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg,
> bool task_in_mem_cgroup(struct task_struct *task,
> const struct mem_cgroup *memcg)
> {
> - struct mem_cgroup *curr = NULL;
> + struct mem_cgroup *curr;
> struct task_struct *p;
> bool ret;
>
> @@ -1351,8 +1351,7 @@ bool task_in_mem_cgroup(struct task_struct *task,
> */
> rcu_read_lock();
> curr = mem_cgroup_from_task(task);
> - if (curr)
> - css_get(&curr->css);
> + css_get(&curr->css);
> rcu_read_unlock();
> }
> /*