diff options
Diffstat (limited to 'mm/oom_kill.c')
| -rw-r--r-- | mm/oom_kill.c | 127 |
1 files changed, 27 insertions, 100 deletions
diff --git a/mm/oom_kill.c b/mm/oom_kill.c index d3490b019d46..5cfda39b3268 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -42,7 +42,8 @@ int sysctl_panic_on_oom; int sysctl_oom_kill_allocating_task; int sysctl_oom_dump_tasks = 1; -static DEFINE_SPINLOCK(zone_scan_lock); + +DEFINE_MUTEX(oom_lock); #ifdef CONFIG_NUMA /** @@ -405,13 +406,12 @@ static atomic_t oom_victims = ATOMIC_INIT(0); static DECLARE_WAIT_QUEUE_HEAD(oom_victims_wait); bool oom_killer_disabled __read_mostly; -static DECLARE_RWSEM(oom_sem); /** * mark_oom_victim - mark the given task as OOM victim * @tsk: task to mark * - * Has to be called with oom_sem taken for read and never after + * Has to be called with oom_lock held and never after * oom has been disabled already. */ void mark_oom_victim(struct task_struct *tsk) @@ -460,14 +460,14 @@ bool oom_killer_disable(void) * Make sure to not race with an ongoing OOM killer * and that the current is not the victim. */ - down_write(&oom_sem); + mutex_lock(&oom_lock); if (test_thread_flag(TIF_MEMDIE)) { - up_write(&oom_sem); + mutex_unlock(&oom_lock); return false; } oom_killer_disabled = true; - up_write(&oom_sem); + mutex_unlock(&oom_lock); wait_event(oom_victims_wait, !atomic_read(&oom_victims)); @@ -634,52 +634,6 @@ int unregister_oom_notifier(struct notifier_block *nb) } EXPORT_SYMBOL_GPL(unregister_oom_notifier); -/* - * Try to acquire the OOM killer lock for the zones in zonelist. Returns zero - * if a parallel OOM killing is already taking place that includes a zone in - * the zonelist. Otherwise, locks all zones in the zonelist and returns 1. - */ -bool oom_zonelist_trylock(struct zonelist *zonelist, gfp_t gfp_mask) -{ - struct zoneref *z; - struct zone *zone; - bool ret = true; - - spin_lock(&zone_scan_lock); - for_each_zone_zonelist(zone, z, zonelist, gfp_zone(gfp_mask)) - if (test_bit(ZONE_OOM_LOCKED, &zone->flags)) { - ret = false; - goto out; - } - - /* - * Lock each zone in the zonelist under zone_scan_lock so a parallel - * call to oom_zonelist_trylock() doesn't succeed when it shouldn't. - */ - for_each_zone_zonelist(zone, z, zonelist, gfp_zone(gfp_mask)) - set_bit(ZONE_OOM_LOCKED, &zone->flags); - -out: - spin_unlock(&zone_scan_lock); - return ret; -} - -/* - * Clears the ZONE_OOM_LOCKED flag for all zones in the zonelist so that failed - * allocation attempts with zonelists containing them may now recall the OOM - * killer, if necessary. - */ -void oom_zonelist_unlock(struct zonelist *zonelist, gfp_t gfp_mask) -{ - struct zoneref *z; - struct zone *zone; - - spin_lock(&zone_scan_lock); - for_each_zone_zonelist(zone, z, zonelist, gfp_zone(gfp_mask)) - clear_bit(ZONE_OOM_LOCKED, &zone->flags); - spin_unlock(&zone_scan_lock); -} - /** * __out_of_memory - kill the "best" process when we run out of memory * @zonelist: zonelist pointer @@ -693,8 +647,8 @@ void oom_zonelist_unlock(struct zonelist *zonelist, gfp_t gfp_mask) * OR try to be smart about which process to kill. Note that we * don't have to be perfect here, we just have to be good. */ -static void __out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, - int order, nodemask_t *nodemask, bool force_kill) +bool out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, + int order, nodemask_t *nodemask, bool force_kill) { const nodemask_t *mpol_mask; struct task_struct *p; @@ -704,10 +658,13 @@ static void __out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, enum oom_constraint constraint = CONSTRAINT_NONE; int killed = 0; + if (oom_killer_disabled) + return false; + blocking_notifier_call_chain(&oom_notify_list, 0, &freed); if (freed > 0) /* Got some memory back in the last second. */ - return; + goto out; /* * If current has a pending SIGKILL or is exiting, then automatically @@ -720,7 +677,7 @@ static void __out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, if (current->mm && (fatal_signal_pending(current) || task_will_free_mem(current))) { mark_oom_victim(current); - return; + goto out; } /* @@ -760,32 +717,8 @@ out: */ if (killed) schedule_timeout_killable(1); -} - -/** - * out_of_memory - tries to invoke OOM killer. - * @zonelist: zonelist pointer - * @gfp_mask: memory allocation flags - * @order: amount of memory being requested as a power of 2 - * @nodemask: nodemask passed to page allocator - * @force_kill: true if a task must be killed, even if others are exiting - * - * invokes __out_of_memory if the OOM is not disabled by oom_killer_disable() - * when it returns false. Otherwise returns true. - */ -bool out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, - int order, nodemask_t *nodemask, bool force_kill) -{ - bool ret = false; - - down_read(&oom_sem); - if (!oom_killer_disabled) { - __out_of_memory(zonelist, gfp_mask, order, nodemask, force_kill); - ret = true; - } - up_read(&oom_sem); - return ret; + return true; } /* @@ -795,27 +728,21 @@ bool out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, */ void pagefault_out_of_memory(void) { - struct zonelist *zonelist; - - down_read(&oom_sem); if (mem_cgroup_oom_synchronize(true)) - goto unlock; + return; - zonelist = node_zonelist(first_memory_node, GFP_KERNEL); - if (oom_zonelist_trylock(zonelist, GFP_KERNEL)) { - if (!oom_killer_disabled) - __out_of_memory(NULL, 0, 0, NULL, false); - else - /* - * There shouldn't be any user tasks runable while the - * OOM killer is disabled so the current task has to - * be a racing OOM victim for which oom_killer_disable() - * is waiting for. - */ - WARN_ON(test_thread_flag(TIF_MEMDIE)); + if (!mutex_trylock(&oom_lock)) + return; - oom_zonelist_unlock(zonelist, GFP_KERNEL); + if (!out_of_memory(NULL, 0, 0, NULL, false)) { + /* + * There shouldn't be any user tasks runnable while the + * OOM killer is disabled, so the current task has to + * be a racing OOM victim for which oom_killer_disable() + * is waiting for. + */ + WARN_ON(test_thread_flag(TIF_MEMDIE)); } -unlock: - up_read(&oom_sem); + + mutex_unlock(&oom_lock); } |