Find attached trace.log (cat /sys/kernel/debug/tracing/trace) and
fuse-debug.log (FUSE daemon with timestamps).

Does that tell you something, or do we need more data? (If so, how?)

Thanks,

On Tue, Mar 3, 2020 at 3:13 PM Tejun Heo <tj@kernel.org> wrote:
>
> Hello,
>
> On Tue, Mar 03, 2020 at 03:03:58PM +0100, Michael Stapelberg wrote:
> > Here’s a /proc/<pid>/stack from when the issue is happening:
> >
> > [<0>] balance_dirty_pages_ratelimited+0x2ca/0x3b0
> > [<0>] __handle_mm_fault+0xe6e/0x1280
> > [<0>] handle_mm_fault+0xbe/0x1d0
> > [<0>] __do_page_fault+0x249/0x4f0
> > [<0>] page_fault+0x1e/0x30
> >
> > How can I obtain the numbers for the next step?
>
> Yes, that's dirty throttling alright. Hopefully, the
> balance_dirty_pages tracepoint which can be enabled from under
> /sys/kernel/debug/tracing/events/writeback/balance_dirty_pages/ should
> tell us why bdp thinks it needs throttling and then we can go from
> there. Unfortunately, I'm rather preoccupied and afraid I don't have a
> lot of bandwidth to work on it myself for the coming weeks.
>
> Thanks.
>
> --
> tejun