Re: mmiotracer hangs the system

From: Andy Shevchenko
Date: Tue Aug 02 2016 - 12:24:22 EST


On Tue, Aug 2, 2016 at 6:31 PM, Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
> On Tue, 2 Aug 2016 18:07:38 +0300
> Andy Shevchenko <andy.shevchenko@xxxxxxxxx> wrote:
>
>> Use another Karol's address (found in MAINTAINERS)
>>
>> On Tue, Aug 2, 2016 at 6:05 PM, Andy Shevchenko
>> <andy.shevchenko@xxxxxxxxx> wrote:
>> > +Cc: Karol, Ingo
>> >
>> > On Tue, Aug 2, 2016 at 1:08 PM, Andy Shevchenko
>> > <andy.shevchenko@xxxxxxxxx> wrote:
>> >> Hi!
>> >>
>> >> I'm trying to use mmio tracer with recent kernels (in this particular
>> >> case today's linux-next).
>> >
>> > Tested on other board and found that v4.5 works while v4.5.7 doesn't.
>> > Bisecting to
>> >
>> > commit d62a28a60562a8ba82e67e13c268245f37e796cb
>> > Author: Karol Herbst <nouveau@xxxxxxxxxxxxxx>
>> > Date: Thu Mar 3 02:03:11 2016 +0100
>> >
>> > x86/mm/kmmio: Fix mmiotrace for hugepages
>> >
>> > commit cfa52c0cfa4d727aa3e457bf29aeff296c528a08 upstream.
>> >
>> > Reverting _helps_ for x86 and x86_64 builds.
>> >
>
> That commit was added in 4.6. Does that kernel work? Maybe it was a bad
> backport?

I don't think so, since linux-next doesn't work until I revert this commit.

I can try exactly v4.6 (yep, I tried stable versions, including
v4.4.16 that's why all of them failed to me) if you still would like
me to do so.


--
With Best Regards,
Andy Shevchenko