diff options
| -rw-r--r-- | include/linux/oom.h | 8 | ||||
| -rw-r--r-- | mm/memcontrol.c | 1 | ||||
| -rw-r--r-- | mm/oom_kill.c | 86 |
3 files changed, 77 insertions, 18 deletions
diff --git a/include/linux/oom.h b/include/linux/oom.h index 628a43242a34..83b9c39bd8b7 100644 --- a/include/linux/oom.h +++ b/include/linux/oom.h @@ -72,6 +72,14 @@ static inline bool oom_task_origin(const struct task_struct *p) extern void mark_oom_victim(struct task_struct *tsk); +#ifdef CONFIG_MMU +extern void try_oom_reaper(struct task_struct *tsk); +#else +static inline void try_oom_reaper(struct task_struct *tsk) +{ +} +#endif + extern unsigned long oom_badness(struct task_struct *p, struct mem_cgroup *memcg, const nodemask_t *nodemask, unsigned long totalpages); diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 1b40dcad2b90..d71d387868e6 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1275,6 +1275,7 @@ static bool mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask, */ if (fatal_signal_pending(current) || task_will_free_mem(current)) { mark_oom_victim(current); + try_oom_reaper(current); goto unlock; } diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 32d8210b8773..850b6ff66bdf 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -412,6 +412,25 @@ bool oom_killer_disabled __read_mostly; #define K(x) ((x) << (PAGE_SHIFT-10)) +/* + * 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; +} + + #ifdef CONFIG_MMU /* * OOM Reaper kernel thread which tries to reap the memory used by the OOM @@ -563,6 +582,53 @@ static void wake_oom_reaper(struct task_struct *tsk) wake_up(&oom_reaper_wait); } +/* Check if we can reap the given task. This has to be called with stable + * tsk->mm + */ +void try_oom_reaper(struct task_struct *tsk) +{ + struct mm_struct *mm = tsk->mm; + struct task_struct *p; + + if (!mm) + return; + + /* + * There might be other threads/processes which are either not + * dying or even not killable. + */ + if (atomic_read(&mm->mm_users) > 1) { + rcu_read_lock(); + for_each_process(p) { + bool exiting; + + if (!process_shares_mm(p, mm)) + continue; + if (same_thread_group(p, tsk)) + continue; + if (fatal_signal_pending(p)) + continue; + + /* + * If the task is exiting make sure the whole thread group + * is exiting and cannot acces mm anymore. + */ + spin_lock_irq(&p->sighand->siglock); + exiting = signal_group_exit(p->signal); + spin_unlock_irq(&p->sighand->siglock); + if (exiting) + continue; + + /* Give up */ + rcu_read_unlock(); + return; + } + rcu_read_unlock(); + } + + wake_oom_reaper(tsk); +} + static int __init oom_init(void) { oom_reaper_th = kthread_run(oom_reaper, NULL, "oom_reaper"); @@ -653,24 +719,6 @@ void oom_killer_enable(void) } /* - * 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; -} - -/* * Must be called while holding a reference to p, which will be released upon * returning. */ @@ -694,6 +742,7 @@ void oom_kill_process(struct oom_control *oc, struct task_struct *p, task_lock(p); if (p->mm && task_will_free_mem(p)) { mark_oom_victim(p); + try_oom_reaper(p); task_unlock(p); put_task_struct(p); return; @@ -873,6 +922,7 @@ bool out_of_memory(struct oom_control *oc) if (current->mm && (fatal_signal_pending(current) || task_will_free_mem(current))) { mark_oom_victim(current); + try_oom_reaper(current); return true; } |