On 09/29, Michal Hocko wrote: > > On Thu 29-09-11 18:37:24, Oleg Nesterov wrote: > > > > Oh, I don't think so. For what? This doesn't close other races, and > > in fact the fatal_signal_pending() this patch adds is itself racy, > > SIGKILL can come in between. > > OK, I think I see your point. You mean that oom will send KILL after > both fatal_signal_pending in refrigerator and signal_pending check in > schedule, right? No, schedule()->signal_pending_state(TASK_UNINTERRUPTIBLE) doesn't check the signals. I simply meant if (fatal_signal_pending()) // <--- SIGKILL from oom try_to_freeze(); > This is what the follow up fix from David is doing. Check frozen in > select_bad_process if the task is TIF_MEMDIE and thaw the process. > > And it seems that the David's follow up fix is sufficient so let's leave > refrigerator alone. Agreed, afaics this should fix all races (although I didn't read the whole discussion, perhaps I missed something else). And in this case we do not even need to modify oom_kill_task/etc, select_bad_process() will be called again and notice the frozen task eventually. Afaics. Or, as Tejun suggests, we can implement the race-free kill-even-if-frozen later. Oleg. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>