On Fri, Dec 02, 2016 at 10:37:35AM +0100, Michal Hocko wrote: > On Thu 01-12-16 21:10:01, Boris Zhmurov wrote: > > Michal Hocko 30/11/16 21:25: > > > > >>> Do I get it right that s@cond_resched_rcu_qs@cond_resched@ didn't help? > > >> > > >> I didn't try that. I've tried 4 patches from Paul's linux-rcu tree. > > >> I can try another portion of patches, no problem :) > > > > > > Replacing cond_resched_rcu_qs in shrink_node_memcg by cond_resched would > > > be really helpful to tell whether we are missing a real scheduling point > > > or whether something more serious is going on here. > > > > Well, I can confirm, that replacing cond_resched_rcu_qs in > > shrink_node_memcg by cond_resched also makes dmesg clean from RCU CPU > > stall warnings. > > > > I've attached patch (just modification of Paul's patch), that fixes RCU > > stall messages in situations, when all memory is used by > > couchbase/memcached + fs cache and linux starts to use swap. > > OK, thanks for the confirmation! I will send a patch because it is true > that we do not have any scheduling point if no pages can be isolated > fromm the LRU. This might be what you are seeing. Thank you both! Thanx, Paul -- 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>