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. -- Michal Hocko SUSE Labs
