On 05/30, Michal Hocko wrote: > > both oom_adj_write and oom_score_adj_write are using task_lock, > check for task->mm and fail if it is NULL. This is not needed because > the oom_score_adj is per signal struct so we do not need mm at all. > The code has been introduced by 3d5992d2ac7d ("oom: add per-mm oom > disable count") but we do not do per-mm oom disable since c9f01245b6a7 > ("oom: remove oom_disable_count"). > > The task->mm check is even not correct because the current thread might > have exited but the thread group might be still alive - e.g. thread > group leader would lead that echo $VAL > /proc/pid/oom_score_adj would > always fail with EINVAL while /proc/pid/task/$other_tid/oom_score_adj > would succeed. This is unexpected at best. > > Remove the lock along with the check to fix the unexpected behavior > and also because there is not real need for the lock in the first place. ACK and we should also remove lock_task_sighand(). as for oom_adj_read() and oom_score_adj_read() we can just remove it right now; it was previously needed to ensure the task->signal != NULL, today this is always true. Oleg. -- 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>