On Tue, Aug 2, 2016 at 9:38 AM, Chris Murphy [off-list ref] wrote:

Yesterday I saw oom killer knocking off processes during a simple cp
-a from one Btrfs to another, in a VM, with kernel
4.8.0-0.rc0.git3.1.fc25.x86_64. The call trace looks different than
Markus' so I'm not sure it's the same problem. It's not always
reproducible. It hasn't happened on 4.7.0 though. According ot koji
this is Linux v4.7-6438-gc624c86

This is 'journalctl -o short-monotonic -b-4 -k'

https://drive.google.com/open?id=0B_2Asp8DGjJ9ZC1JSDJnaWpnSEE

Btrfs volume 2 is created at [  625.769736]  and mounted at [
640.119150], with the copy starting shortly after that. OOM happens at
[  856.212658] . There are a bunch of earlier bug messages, BUG:
sleeping function called from invalid context at mm/slab.h:393.


-- 
Chris Murphy