[Mesa-dev] [PATCH 2/2] gallium/radeon: use max_alloc_size

[Vedran Miletić]

On 07/01/2016 02:27 PM, Marek Olšák wrote:
> On Fri, Jul 1, 2016 at 1:45 PM, Vedran Miletić <vedran at miletic.net> wrote:
>> On 07/01/2016 11:11 AM, Marek Olšák wrote:
>>>
>>> On Fri, Jul 1, 2016 at 10:54 AM, Marek Olšák <maraeo at gmail.com> wrote:
>>>>
>>>> On Fri, Jul 1, 2016 at 2:52 AM, Vedran Miletić <vedran at miletic.net>
>>>> wrote:
>>>>>
>>>>> On 07/01/2016 01:29 AM, Marek Olšák wrote:
>>>>>>
>>>>>>
>>>>>> From: Marek Olšák <marek.olsak at amd.com>
>>>>>>
>>>>>> also fix max_global_size to take a maximum of {vram_size, gart_size}
>>>>>> ---
>>>>>>  src/gallium/drivers/r600/r600_pipe.c          | 2 +-
>>>>>>  src/gallium/drivers/radeon/r600_pipe_common.c | 9 +++------
>>>>>>  src/gallium/drivers/radeonsi/si_pipe.c        | 2 +-
>>>>>>  3 files changed, 5 insertions(+), 8 deletions(-)
>>>>>>
>>>>>> diff --git a/src/gallium/drivers/r600/r600_pipe.c
>>>>>> b/src/gallium/drivers/r600/r600_pipe.c
>>>>>> index 119c76b..55bbde1 100644
>>>>>> --- a/src/gallium/drivers/r600/r600_pipe.c
>>>>>> +++ b/src/gallium/drivers/r600/r600_pipe.c
>>>>>> @@ -301,7 +301,7 @@ static int r600_get_param(struct pipe_screen*
>>>>>> pscreen,
>>>>>> enum pipe_cap param)
>>>>>>                 return 0;
>>>>>>
>>>>>>         case PIPE_CAP_MAX_TEXTURE_BUFFER_SIZE:
>>>>>> -               return MIN2(rscreen->b.info.vram_size, 0xFFFFFFFF);
>>>>>> +               return MIN2(rscreen->b.info.max_alloc_size,
>>>>>> 0xFFFFFFFF);
>>>>>>
>>>>>>          case PIPE_CAP_MIN_MAP_BUFFER_ALIGNMENT:
>>>>>>                  return R600_MAP_BUFFER_ALIGNMENT;
>>>>>> diff --git a/src/gallium/drivers/radeon/r600_pipe_common.c
>>>>>> b/src/gallium/drivers/radeon/r600_pipe_common.c
>>>>>> index d7f1d41..f75fa6c 100644
>>>>>> --- a/src/gallium/drivers/radeon/r600_pipe_common.c
>>>>>> +++ b/src/gallium/drivers/radeon/r600_pipe_common.c
>>>>>> @@ -864,8 +864,8 @@ static int r600_get_compute_param(struct
>>>>>> pipe_screen
>>>>>> *screen,
>>>>>>                          * 4 * MAX_MEM_ALLOC_SIZE.
>>>>>>                          */
>>>>>>                         *max_global_size = MIN2(4 * max_mem_alloc_size,
>>>>>> -                               rscreen->info.gart_size +
>>>>>> -                               rscreen->info.vram_size);
>>>>>> +
>>>>>> MAX2(rscreen->info.gart_size,
>>>>>> +
>>>>>> rscreen->info.vram_size));
>>>>>
>>>>>
>>>>>
>>>>> Can't you also use info.max_alloc_size here?
>>>>
>>>>
>>>> I can do *max_global_size = max_alloc_size; Does that sound good?
>>>
>>>
>>> Even if max_alloc_size can be 256 MB?
>>>
>>> Marek
>>> _______________________________________________
>>> mesa-dev mailing list
>>> mesa-dev at lists.freedesktop.org
>>> https://lists.freedesktop.org/mailman/listinfo/mesa-dev
>>>
>>
>> How about
>>
>> *max_global_size = MIN2(4 * max_mem_alloc_size,
>>                         rscreen->info.max_alloc_size);
>>
>> Would that work? That avoids calculating the same value in two distinct
>> places, since rscreen->info.max_alloc_size = MAX2(rscreen->info.gart_size,
>> rscreen->info.vram_size) for both radeon and amdgpu.
>
> max_mem_alloc_size == max_alloc_size. Thus:
>
> MIN2(4 * max_mem_alloc_size, max_alloc_size) == max_alloc_size
>
> Marek
> _______________________________________________
> mesa-dev mailing list
> mesa-dev at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/mesa-dev
>

Right, indeed.

In the case memory allocation is limited to 256 MB, this could would 
give 256 MB, while the code you initially had will give 1 GB of memory 
or VRAM or GTT, so it's definitely a better option.

Regards,
Vedran

-- 
Vedran Miletić
vedran.miletic.net