[Mesa-dev] [PATCH 1/3] st/mesa: recreate sampler view on context change v2

[Christian König]

Am 24.03.2014 17:13, schrieb Brian Paul:
> On 03/24/2014 10:04 AM, Christian König wrote:
>> Am 24.03.2014 16:36, schrieb Brian Paul:
>>> On 03/24/2014 08:06 AM, Christian König wrote:
>>>> From: Christian König <christian.koenig at amd.com>
>>>>
>>>> With shared glx contexts it is possible that a texture is create and
>>>> used
>>>> in one context and then used in another one resulting in incorrect
>>>> sampler view usage.
>>>>
>>>> v2: avoid template copy
>>>>
>>>> Signed-off-by: Christian König <christian.koenig at amd.com>
>>>> Cc: "10.0 10.1" <mesa-stable at lists.freedesktop.org>
>>>> ---
>>>>   src/mesa/state_tracker/st_atom_texture.c | 7 +++++++
>>>>   1 file changed, 7 insertions(+)
>>>>
>>>> diff --git a/src/mesa/state_tracker/st_atom_texture.c
>>>> b/src/mesa/state_tracker/st_atom_texture.c
>>>> index 3557a3f..dc7f635 100644
>>>> --- a/src/mesa/state_tracker/st_atom_texture.c
>>>> +++ b/src/mesa/state_tracker/st_atom_texture.c
>>>> @@ -198,6 +198,13 @@ st_get_texture_sampler_view_from_stobj(struct
>>>> st_texture_object *stObj,
>>>>      if (!stObj->sampler_view) {
>>>>         stObj->sampler_view =
>>>>            st_create_texture_sampler_view_from_stobj(pipe, stObj,
>>>> samp, format);
>>>> +
>>>> +   } else if (stObj->sampler_view->context != pipe) {
>>>> +      /* Recreate view in correct context, use existing view as
>>>> template */
>>>> +      struct pipe_sampler_view *sv =
>>>> +         pipe->create_sampler_view(pipe, stObj->pt,
>>>> stObj->sampler_view);
>>>> + pipe_sampler_view_reference(&stObj->sampler_view, NULL);
>>>> +      stObj->sampler_view = sv;
>>>>      }
>>>>
>>>>      return stObj->sampler_view;
>>>>
>>>
>>> My concern with this is if there really are multiple contexts using
>>> one texture, we're going to continuously destroy and create sampler
>>> views when we validate state.  Right?
>>
>> Yes that's correct and it also concerned me as well.
>>
>>>
>>> Ultimately, the right solution might be to have a list of sampler
>>> views per texture, one sampler view per context.  Since there usually
>>> aren't too many contexts sharing textures, a linked list would
>>> probably be OK.
>>>
>>
>> Completely agree, but this patchset is meant to be a bugfix for the
>> crashes we experience with 10.x. For master a solution with a linked
>> list should work better indeed.
>
> OK, let's put a 'XXX' comment describing that solution in the code for 
> now.
>
> With that, Reviewed-by: Brian Paul <brianp at vmware.com>
>

Thanks, I've added the comment and pushed the result upstream.

What about the other two patches? I would like to push at least #2 as 
well, cause it is clearly a bugfix.

> Will you try to implement the linked list?

Sure, shouldn't be to much of a problem.

Christian.

>
> -Brian
>