On Fri, Jan 09, 2015 at 12:05:55PM +0100, Michal Hocko wrote: ... > @@ -142,7 +118,6 @@ static bool check_frozen_processes(void) > int freeze_processes(void) > { > int error; > - int oom_kills_saved; > > error = __usermodehelper_disable(UMH_FREEZING); > if (error) > @@ -157,29 +132,22 @@ int freeze_processes(void) > pm_wakeup_clear(); > pr_info("Freezing user space processes ... "); > pm_freezing = true; > - oom_kills_saved = oom_kills_count(); > error = try_to_freeze_tasks(true); > if (!error) { > __usermodehelper_set_disable_depth(UMH_DISABLED); > - oom_killer_disable(); > - > - /* > - * There might have been an OOM kill while we were > - * freezing tasks and the killed task might be still > - * on the way out so we have to double check for race. > - */ > - if (oom_kills_count() != oom_kills_saved && > - !check_frozen_processes()) { > - __usermodehelper_set_disable_depth(UMH_ENABLED); > - pr_cont("OOM in progress."); > - error = -EBUSY; > - } else { > - pr_cont("done."); > - } > + pr_cont("done."); > } > pr_cont("\n"); > BUG_ON(in_atomic()); > > + /* > + * Now that the whole userspace is frozen we need to disbale > + * the OOM killer to disallow any further interference with > + * killable tasks. > + */ > + if (!error && !oom_killer_disable()) So, previously, oom killer was disabled at the top of freeze_kernel_threads(), right? I think that was the better spot to do that. We don't want to disable oom killer before the system is just about to enter total quiescence which is freeze_kernel_threads(). We want to delay this as long as possible. Let's please disable oom killing in at the top of freeze_kernel_threads() and re-enable at the bottom of thaw_kernel_threads(). Thanks. -- tejun -- 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/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>