On Mon, 14 Mar 2011, Linus Torvalds wrote: > The combination of testing PF_EXITING and p->mm just doesn't seem to > make any sense. > Right, it doesn't (and I recently removed testing the combination from select_bad_process() in -mm). The check for PF_EXITING in the oom killer is purely to avoid needlessly killing tasks when something is already exiting and will (hopefully) be freeing its memory soon. If an eligible thread is found to be PF_EXITING, the oom killer will defer indefinitely unless it happens to be current. If it happens to be current, then it is automatically selected so it gets access to the needed memory reserves. We do need to ensure that behavior doesn't preempt any task from being killed if there's an eligible thread other than current that never actually detaches its ->mm (oom-skip-zombies-when-iterating-tasklist.patch in -mm filters all threads without an ->mm). That can happen if mm->mmap_sem never gets released by a thread and that's why an earlier change that is already in your tree automatically gives current access to memory reserves immediately upon calling the oom killer if it has a pending SIGKILL. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx 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>