Re: page_cache_tree_insert WARN_ON hit on 4.8+

From: Dave Jones
Date: Tue Oct 04 2016 - 13:46:53 EST

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,


> 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.