[Piglit] RFC enhance dmesg handling in piglit

[Daniel Vetter]

On Tue, Nov 12, 2013 at 7:53 PM, Dylan Baker <baker.dylan.c at gmail.com> wrote:
> On Tuesday, November 12, 2013 07:21:50 PM Daniel Vetter wrote:
>> On Tue, Nov 12, 2013 at 07:53:58AM -0800, Dylan Baker wrote:
>> > This series cleans up the dmesg handlingin piglit by implementing a
>> > module with two classes, one for reading dmesg, and the other that acts
>> > as a dummy class on non-posix systems, this allows dmesg to just always
>> > be turned on all the time.
>> >
>> > Secondly this new dmesg class has the ability to filter dmesg entries,
>> > searching for specific regular expressions and classifying them as
>> > either 'warns' or 'fails'.
>> >
>> > Currently the filtering is fairly simply, and I expect to have at least
>> > one more iteration of these patches with more enries for dmesg. It
>> > curretly as an example marks any test the segfaults as a 'warn', and
>> > searches for some entries emmitted by the i915 driver and marks them
>> > 'fail'.
>>
>> Looks like we're colliding a bit here, cool ;-)
>>
>> Essentially for i-g-t testcases the rule is that everything in dmesg which
>> isn't at the debug/info level should make the test fail. Otoh if the tests
>> succeeds and there's only new info/debug stuff in dmesg, then the result
>> state shouldn't be set to 'warn'. This is because a lot of our tests are
>> expected to generate info level messages (e.g. simulated gpu hangs or
>> module reload). And we often enable full drm debugging when running tests,
>> which spews a lot.
>>
>> So either we need to capture the raw dmesg output to be able to pattern
>> match log-levels (dmesg -r). Or we do the cheap trick I've done in the
>> patch submitted yesterday of simply filtering out unwanted levels at the
>> source.
>>
>> But overall I really want dmesg capture support by default for igt tests.
>> -Daniel
>
> So it sounds like the right solution would be to have a set of filters that
> make sense for piglit's "native" tests, and then allow external tests to
> overwrite the filters before calling dmesg. Does that sound like a workable
> solution?
>
> I actually assumed that your dmesg filtering would land, and I'd rebase on top
> of it.

If Marek is ok with the filtering by default then I think we can go
ahead with that. But if other people are also interested in filtering
dmesg using the log levels then maybe we should switch to capturing
them first.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch