GPU lockup dumping

[Jerome Glisse]

On Wed, May 23, 2012 at 8:34 AM, Christian König
<deathsimple at vodafone.de> wrote:
> On 23.05.2012 11:27, Dave Airlie wrote:
>>
>> On Thu, May 17, 2012 at 7:28 PM,<j.glisse at gmail.com>  wrote:
>>>
>>> So here is improved patchset, where i splited ground work necessary
>>> for the dumping into their own patch. The debugfs improvement could
>>> probably be usefull to intel instead of having i915 have it's own
>>> debugfs file stuff.
>>>
>>> The lockup dumping public api have been move into radeon_drm.h
>>>
>>> Stressing the fact again that dump are self contained ie they have
>>> all the data needed to be replayed (vertex, indices, shader, texture,
>>> ...).
>>>
>>> Would really like to get this into 3.5, the new API is pretty much
>>> straightforward and userspace tools can easily be made to convert
>>> it to other format. The change to the driver is self contained.
>>
>> I really don't like introducing this at this stage into 3.5,
>>
>> I'd really like a good review of the API and what information we provide
>> along with how extensible it is.
>>
>> I'm still not convinced replay is what we want in the field, I know its
>> what
>> *you* want, but I think apitrace stuff in userspace pretty much covers
>> the replaying situation. So I'd have to look at this and see how easy
>> it makes disecting command streams etc.
>>
>> Dave.
>
>
> I agree that it might not be a good idea to push that into 3.5, since at
> least I (and I also think Alex) didn't had time to look into it yet. On the
> other hand the patches look quite reasonable.
>
> But I still wanted to throw in a requirement from my day to day work, maybe
> that helps finding a more general solution:
> When we start to work with more parts of the chip it might be necessary to
> dump everything that is currently "in the fly". For example I had a whole
> bunch of problems where copying data around with a 3D Blit and then missing
> a sync between this job and a job on another rings causes a "hiccup" in the
> hardware.
>
> I know that this isn't your focus and that is absolutely ok with me, cause
> the format you are introducing is just used in debugfs and so not part of
> any stable API (at least not in my understanding), but you should still keep
> in mind that we might need to extend it into that direction in the future.
>
> Christian.

Note that my format is also done with that in mind, it can capture ib
from all rings. The only thing i don't think worth capturing are the
ring themself because there would be no way to replay them without
adding some new special API.

Cheers,
Jerome