[Intel-gfx] [PATCH libdrm 0/5] improve reuse implementation

[Emil Velikov]

On 16 March 2018 at 08:43, Daniel Vetter <daniel at ffwll.ch> wrote:
> On Thu, Mar 15, 2018 at 06:20:09PM -0700, James Xiong wrote:
>> From: "Xiong, James" <james.xiong at intel.com>
>>
>> With gem_reuse enabled, when a buffer size is different than
>> the sizes of buckets, it is aligned to the next bucket's size,
>> which means about 25% more memory than the requested is allocated
>> in the worst senario. For example:
>>
>> Orignal size    Actual
>> 32KB+1Byte      40KB
>> .
>> .
>> .
>> 8MB+1Byte       10MB
>> .
>> .
>> .
>> 96MB+1Byte      112MB
>>
>> This is very memory expensive and make the reuse feature less
>> favorable than it deserves to be.
>>
>> This series aligns the reuse buffer size on page size instead to
>> save memory. Performed gfxbench tests on Gen9 without LLC, the
>> performances and reuse ratioes (reuse count/allocation count) were
>> same as before, saved memory usage by 1% ~ 7%(gl_manhattan: peak
>> allocated memory size was reduced from 448401408 to 419078144).
>>
>> v2: split the patch to a series of small functional changes (Chris)
>
> Mesa gen driver stopped using the libdrm buffer allocator. The gen2/3
> driver still uses it, but I think that's not the one you benchmarked. The
> 17.1 release was the first one with that change.
>
> I think you want to port your changes over to mesa to future proof it,
> merging this to upstream makes little sense.

Perhaps it can have in both? After all i915, libva and beignet still
make use of libdrm_intel.
The Mesa copy has changed drastically so this series might need serious rework.

-Emil