[Intel-gfx] [PATCH 15/40] drm/i915: Priority boost for new clients

[Tvrtko Ursulin]

On 25/09/2018 10:06, Chris Wilson wrote:
> Quoting Tvrtko Ursulin (2018-09-25 09:57:11)
>>
>> On 25/09/2018 09:26, Chris Wilson wrote:
>>> Quoting Chris Wilson (2018-09-25 09:01:06)
>>>> Quoting Tvrtko Ursulin (2018-09-24 11:29:52)
>>>>>
>>>>> On 19/09/2018 20:55, Chris Wilson wrote:
>>>>>> diff --git a/drivers/gpu/drm/i915/i915_scheduler.h b/drivers/gpu/drm/i915/i915_scheduler.h
>>>>>> index 7edfad0abfd7..93e43e263d8c 100644
>>>>>> --- a/drivers/gpu/drm/i915/i915_scheduler.h
>>>>>> +++ b/drivers/gpu/drm/i915/i915_scheduler.h
>>>>>> @@ -19,12 +19,14 @@ enum {
>>>>>>         I915_PRIORITY_INVALID = INT_MIN
>>>>>>     };
>>>>>>     
>>>>>> -#define I915_USER_PRIORITY_SHIFT 0
>>>>>> +#define I915_USER_PRIORITY_SHIFT 1
>>>>>>     #define I915_USER_PRIORITY(x) ((x) << I915_USER_PRIORITY_SHIFT)
>>>>>>     
>>>>>>     #define I915_PRIORITY_COUNT BIT(I915_USER_PRIORITY_SHIFT)
>>>>>>     #define I915_PRIORITY_MASK (-I915_PRIORITY_COUNT)
>>>>>>     
>>>>>> +#define I915_PRIORITY_NEWCLIENT      ((u8)BIT(0))
>>>>>
>>>>> Is the cast important and why?
>>>>
>>>> Unreliable memory says there was something iffy about the code generation
>>>> at one point.
>>>
>>> drivers/gpu/drm/i915/intel_lrc.c: In function ‘__unwind_incomplete_requests’:
>>> drivers/gpu/drm/i915/intel_lrc.c:272:13: error: overflow in conversion from ‘long unsigned int’ to ‘int’ changes value from ‘18446744071562067969’ to ‘-2147483647’ [-Werror=overflow]
>>>     int prio = I915_PRIORITY_INVALID | I915_PRIORITY_NEWCLIENT;
>>
>> So correct cast would be (int)BIT(..), or maybe not use BIT for less
>> confusion?
> 
> It's a bit, I like them unsigned to avoid sign extension confusion most
> of the time. (What am I saying, sign extension is already confusing and
> no matter what you do, you always want the opposite.)

Okay, it's internal so no big deal either way.

Regards,

Tvrtko