diff options
| -rw-r--r-- | mm/oom_kill.c | 22 |
1 files changed, 20 insertions, 2 deletions
diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 2b6e8809d7a8..e4778285d8d1 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -474,6 +474,24 @@ void oom_killer_enable(void) oom_killer_disabled = false; } +/* + * task->mm can be NULL if the task is the exited group leader. So to + * determine whether the task is using a particular mm, we examine all the + * task's threads: if one of those is using this mm then this task was also + * using it. + */ +static bool process_shares_mm(struct task_struct *p, struct mm_struct *mm) +{ + struct task_struct *t; + + for_each_thread(p, t) { + struct mm_struct *t_mm = READ_ONCE(t->mm); + if (t_mm) + return t_mm == mm; + } + return false; +} + #define K(x) ((x) << (PAGE_SHIFT-10)) /* * Must be called while holding a reference to p, which will be released upon @@ -521,7 +539,7 @@ void oom_kill_process(struct oom_control *oc, struct task_struct *p, list_for_each_entry(child, &t->children, sibling) { unsigned int child_points; - if (child->mm == p->mm) + if (process_shares_mm(child, p->mm)) continue; /* * oom_badness() returns 0 if the thread is unkillable @@ -575,7 +593,7 @@ void oom_kill_process(struct oom_control *oc, struct task_struct *p, */ rcu_read_lock(); for_each_process(p) { - if (p->mm != mm) + if (!process_shares_mm(p, mm)) continue; if (same_thread_group(p, victim)) continue; |