On Tue, Feb 17, 2015 at 08:57:05PM +0900, Tetsuo Handa wrote: > Johannes Weiner wrote: > > On Mon, Feb 16, 2015 at 08:23:16PM +0900, Tetsuo Handa wrote: > > > (2) Implement TIF_MEMDIE timeout. > > > > How about something like this? This should solve the deadlock problem > > in the page allocator, but it would also simplify the memcg OOM killer > > and allow its use by in-kernel faults again. > > Yes, basic idea would be same with > http://marc.info/?l=linux-mm&m=142002495532320&w=2 . > > But Michal and David do not like the timeout approach. > http://marc.info/?l=linux-mm&m=141684783713564&w=2 > http://marc.info/?l=linux-mm&m=141686814824684&w=2 I'm open to suggestions, but we can't just stick our heads in the sand and pretend that these are just unrelated bugs. They're not. As long as it's legal to enter the allocator with *anything* that can prevent another random task in the system from making progress, we have this deadlock potential. One side has to give up, and it can't be the page allocator because it has to support __GFP_NOFAIL allocations, which are usually exactly the allocations that are buried in hard-to-unwind state that is likely to trip up exiting OOM victims. The alternative would be lock dependency tracking, but I'm not sure it can be realistically done for production environments. -- 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>