On Sat 10-09-16 02:28:40, Tetsuo Handa wrote: > Commit c32b3cbe0d067a9c ("oom, PM: make OOM detection in the freezer path > raceless") inserted a WARN_ON() into pagefault_out_of_memory() in order > to warn when we raced with disabling the OOM killer. But emitting same > backtrace forever after the OOM killer/reaper are disabled is pointless > because the system is already OOM livelocked. How that would that be forever? Pagefaults are not GFP_NOFAIL and the killed task would just enter the exit path. Sure we will see one warning per each g-u-p after that point but the above text seems to be misleading to me. So can you just drop the last sentence? > Now, patch "oom, suspend: fix oom_killer_disable vs. pm suspend properly" > introduced a timeout for oom_killer_disable(). Even if we raced with > disabling the OOM killer and the system is OOM livelocked, the OOM killer > will be enabled eventually (in 20 seconds by default) and the OOM livelock > will be solved. Therefore, we no longer need to warn when we raced with > disabling the OOM killer. That being said I guess the warning is really no longer needed as you say. So I am not against the patch. But the changelog wording seems misleading to me. > Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> > Cc: Michal Hocko <mhocko@xxxxxxx> > Cc: David Rientjes <rientjes@xxxxxxxxxx> > Cc: Johannes Weiner <hannes@xxxxxxxxxxx> > --- > mm/oom_kill.c | 12 +----------- > 1 file changed, 1 insertion(+), 11 deletions(-) > > diff --git a/mm/oom_kill.c b/mm/oom_kill.c > index 0034baf..f284e92 100644 > --- a/mm/oom_kill.c > +++ b/mm/oom_kill.c > @@ -1069,16 +1069,6 @@ void pagefault_out_of_memory(void) > > if (!mutex_trylock(&oom_lock)) > return; > - > - if (!out_of_memory(&oc)) { > - /* > - * 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)); > - } > - > + out_of_memory(&oc); > mutex_unlock(&oom_lock); > } > -- > 1.8.3.1 -- Michal Hocko SUSE Labs -- 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>