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
/**
static DECLARE_WAIT_QUEUE_HEAD(oom_victims_wait);
bool oom_killer_disabled __read_mostly;
-static DECLARE_RWSEM(oom_sem);
/**
- * mark_tsk_oom_victim - marks the given task as OOM victim.
+ * 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_tsk_oom_victim(struct task_struct *tsk)
+void mark_oom_victim(struct task_struct *tsk)
{
WARN_ON(oom_killer_disabled);
/* OOM killer might race with memcg OOM */
}
/**
- * unmark_oom_victim - unmarks the current task as OOM victim.
- *
- * Wakes up all waiters in oom_killer_disable()
+ * exit_oom_victim - note the exit of an OOM victim
*/
-void unmark_oom_victim(void)
+void exit_oom_victim(void)
{
- if (!test_and_clear_thread_flag(TIF_MEMDIE))
- return;
+ clear_thread_flag(TIF_MEMDIE);
- down_read(&oom_sem);
- /*
- * There is no need to signal the lasst oom_victim if there
- * is nobody who cares.
- */
- if (!atomic_dec_return(&oom_victims) && oom_killer_disabled)
+ if (!atomic_dec_return(&oom_victims))
wake_up_all(&oom_victims_wait);
- up_read(&oom_sem);
}
/**
* 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));
*/
void oom_killer_enable(void)
{
- down_write(&oom_sem);
oom_killer_disabled = false;
- up_write(&oom_sem);
}
#define K(x) ((x) << (PAGE_SHIFT-10))
*/
task_lock(p);
if (p->mm && task_will_free_mem(p)) {
- mark_tsk_oom_victim(p);
+ mark_oom_victim(p);
task_unlock(p);
put_task_struct(p);
return;
dump_header(p, gfp_mask, order, memcg, nodemask);
task_lock(p);
- pr_err("%s: Kill process %d (%s) score %d or sacrifice child\n",
+ pr_err("%s: Kill process %d (%s) score %u or sacrifice child\n",
message, task_pid_nr(p), p->comm, points);
task_unlock(p);
/* mm cannot safely be dereferenced after task_unlock(victim) */
mm = victim->mm;
- mark_tsk_oom_victim(victim);
+ mark_oom_victim(victim);
pr_err("Killed process %d (%s) total-vm:%lukB, anon-rss:%lukB, file-rss:%lukB\n",
task_pid_nr(victim), victim->comm, K(victim->mm->total_vm),
K(get_mm_counter(victim->mm, MM_ANONPAGES)),
}
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
* 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;
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
*/
if (current->mm &&
(fatal_signal_pending(current) || task_will_free_mem(current))) {
- mark_tsk_oom_victim(current);
- return;
+ mark_oom_victim(current);
+ goto 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;
}
/*
*/
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);
}
projects / mirror_ubuntu-artful-kernel.git / blobdiff