On 2017/03/10 20:44, Tetsuo Handa wrote: > Michal Hocko wrote: >> On Thu 09-03-17 13:05:40, Johannes Weiner wrote: >>>> It may be OK, I just do not understand all the implications. >>>> >>>> I like the general direction your patch takes the code in, >>>> but I would like to understand it better... >>> >>> I feel the same way. The throttling logic doesn't seem to be very well >>> thought out at the moment, making it hard to reason about what happens >>> in certain scenarios. >>> >>> In that sense, this patch isn't really an overall improvement to the >>> way things work. It patches a hole that seems to be exploitable only >>> from an artificial OOM torture test, at the risk of regressing high >>> concurrency workloads that may or may not be artificial. >>> >>> Unless I'm mistaken, there doesn't seem to be a whole lot of urgency >>> behind this patch. Can we think about a general model to deal with >>> allocation concurrency? >> >> I am definitely not against. There is no reason to rush the patch in. > > I don't hurry if we can check using watchdog whether this problem is occurring > in the real world. I have to test corner cases because watchdog is missing. Today I tested linux-next-20170321 with not so insane stress, and I again hit this problem. Thus, I think this problem might occur in the real world. http://I-love.SAKURA.ne.jp/tmp/serial-20170321.txt.xz (Logs up to before swapoff are eliminated.) ---------- [ 2250.175109] MemAlloc-Info: stalling=16 dying=0 exiting=4 victim=0 oom_count=1155386 [ 2257.535653] MemAlloc-Info: stalling=16 dying=0 exiting=4 victim=0 oom_count=1155386 [ 2319.806880] MemAlloc-Info: stalling=19 dying=0 exiting=4 victim=0 oom_count=1155386 [ 2320.722282] MemAlloc-Info: stalling=19 dying=0 exiting=4 victim=0 oom_count=1155386 [ 2381.243393] MemAlloc-Info: stalling=20 dying=0 exiting=4 victim=0 oom_count=1155386 [ 2389.777052] MemAlloc-Info: stalling=20 dying=0 exiting=4 victim=0 oom_count=1155386 [ 2450.878287] MemAlloc-Info: stalling=20 dying=0 exiting=4 victim=0 oom_count=1155386 [ 2459.386321] MemAlloc-Info: stalling=20 dying=0 exiting=4 victim=0 oom_count=1155386 [ 2520.500633] MemAlloc-Info: stalling=20 dying=0 exiting=4 victim=0 oom_count=1155386 [ 2529.042088] MemAlloc-Info: stalling=20 dying=0 exiting=4 victim=0 oom_count=1155386 ---------- -- 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>
