On Sun, 14 Dec 2014 15:34:46 +0300 Timofey Titovets <nefelim4ag@gmail.com> wrote:

> io_schedule_timeout(5*HZ);
> Introduced for avoidance dm bug:
> http://linux.derkeiler.com/Mailing-Lists/Kernel/2006-08/msg04869.html
> According to description must be replaced with io_schedule()
>
> I replace it and recompile kernel, tested it by following script:

How do we know DM doesn't still depend on the io_schedule_timeout()?

It would require input from the DM developers and quite a lot of
stress-testing of many kernel subsystems before we could make this
change.