From: Michal Hocko <mhocko@xxxxxxxx> Add a short documentation about what is the oom_lock scope. Requested-by: David Rientjes <rientjes@xxxxxxxxxx> Signed-off-by: Michal Hocko <mhocko@xxxxxxxx> --- mm/oom_kill.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index ed9d473c571e..32e6f7becb40 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -53,6 +53,14 @@ int sysctl_panic_on_oom; int sysctl_oom_kill_allocating_task; int sysctl_oom_dump_tasks = 1; +/* + * Serializes oom killer invocations (out_of_memory()) from all contexts to + * prevent from over eager oom killing (e.g. when the oom killer is invoked + * from different domains). + * + * oom_killer_disable() relies on this lock to stabilize oom_killer_disabled + * and mark_oom_victim + */ DEFINE_MUTEX(oom_lock); #ifdef CONFIG_NUMA -- 2.18.0
