Re: page_cache_tree_insert WARN_ON hit on 4.8+

[Dave Jones]

On Tue, Oct 04, 2016 at 07:34:25PM +0200, Johannes Weiner wrote:
 > Hi Dave,
 > 
 > On Tue, Oct 04, 2016 at 01:09:55PM -0400, Dave Jones wrote:
 > > Hit this during a trinity run.
 > > Kernel built from v4.8-1558-g21f54ddae449
 > > 
 > > WARNING: CPU: 0 PID: 5670 at ./include/linux/swap.h:276 page_cache_tree_insert+0x198/0x1b0
 > 
 > Thanks for the report.
 > 
 > I've been trying to reproduce this too after Linus got hit by it. Is
 > there any way to trace back the steps what trinity was doing exactly?

That run didn't have logging enabled, so not sure..

 > What kind of file(system) this was operating on,

btrfs

 > file size, what the /proc/vmstat delta before the operation until the trigger looks like?

No idea.

Let me play with some options, see if I can narrow it down.

	Dave