[arch-general] Help diagnosing kworker 'bug'

[Oon-Ee Ng]

On Sat, Aug 9, 2014 at 11:18 AM, Anatol Pomozov
<anatol.pomozov at gmail.com> wrote:
> Hi
>
> Another way to get more information about this problem is to use
> kernel traces. Let's enable block and writeback events:
>
> sudo su
> cd /sys/kernel/debug/tracing
> echo 1 > events/writeback/enable
> echo 1 > events/block/enable
> echo 1 > tracing_on
> cat trace_pipe
>
> there will some information like processid, inode... Maybe you'll see
> some pattern in the writes etc..
>
> In any case this problem sounds like an upstream issue and it is
> better to contact them.

I've emailed the btrfs list and will follow up there. I could not make
head nor tail of block/writeback events, seemed similar with the
problematic kernel versions and the non-problematic ones. It could be
that the kernel upgrade merely exposed an underlying issue.

In any case, I uploaded a print screen showing the iotop and perf top
readings.... hopefully someone can understand it.
https://db.tt/TSh5piq6