CIK hangs with kernel 3.15, bisected

[Marek Olšák]

Hi Christian,

I have tested it and it doesn't fix the hangs.

(Also, I don't like the patch, because it reverts the behavior I added
for userspace buffers.)

Marek



On Sat, May 10, 2014 at 6:34 PM, Christian König
<deathsimple at vodafone.de> wrote:
> Couldn't reproduce the issue so far. So the attached patch is just a
> complete shoot into the dark found by rereading the code, but it might
> actually be the problem.
>
> Please give it a try.
>
> Going to keep testing in the meantime,
> Christian.
>
> Am 10.05.2014 10:23, schrieb Christian König:
>
>>> I see hangs with kernel 3.15 and SI under memory pressure, e.g. if I boot
>>> with radeon.vramlimit=256 and then run Xonotic timedemo with high settings.
>>> I haven't had a chance to bisect it yet, but it might be a similar problem.
>>
>> Sounds like the same issue to me. Thx for the good test case.
>>
>>> Any idea what is wrong with it?
>>
>> Actually I already wondered that it went so smooth without any regression
>> so far, didn't noticed the bug in bugzilla.kernel.org yet.
>>
>>> Some of the tests allocate a lot of MSAA textures and the tests also
>>> run in parallel, which creates a lot of memory pressure and probably
>>> causes buffer evictions.
>>
>> Sounds like the underlying problem to me. We probably evict some part of a
>> page table without updating the page directory. Going to dig into it today,
>> it's probably just a one liner missing somewhere in the VM code.
>>
>> Christian.
>>
>> Am 09.05.2014 23:39, schrieb Grigori Goronzy:
>>>
>>> On 09.05.2014 20:03, Marek Olšák wrote:
>>>>
>>>>
>>>> This commit which first appeared in 3.15-rc1 causes hangs on Bonaire:
>>>> [...]
>>>>
>>>> The simplest way to reproduce the hangs is to run piglit with these
>>>> parameters:
>>>> -t texelFetch.fs
>>>>
>>>> Some of the tests allocate a lot of MSAA textures and the tests also
>>>> run in parallel, which creates a lot of memory pressure and probably
>>>> causes buffer evictions.
>>>>
>>>
>>> I see hangs with kernel 3.15 and SI under memory pressure, e.g. if I boot
>>> with radeon.vramlimit=256 and then run Xonotic timedemo with high settings.
>>> I haven't had a chance to bisect it yet, but it might be a similar problem.
>>>
>>> Grigori
>>
>>
>