lkml.org 
[lkml]   [2016]   [Dec]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: INFO: rcu_sched detected stalls on CPUs/tasks with `kswapd` and `mem_cgroup_shrink_node`
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

\
 
 \ /
  Last update: 2016-12-02 14:52    [W:0.114 / U:0.172 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site