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

[Christian König]

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.

Christian.

> -Brian
>
>
>
> _______________________________________________
> mesa-dev mailing list
> mesa-dev at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/mesa-dev