Re: [Intel-gfx] [PATCH v3 5/6] drm/i915/ttm: Implement asynchronous TTM moves

["Thomas Hellström" <thomas.hellstrom@linux.intel.com>]

On 11/15/21 18:16, Matthew Auld wrote:

Thanks for reviewing, Matthew,

I'll take a look at the comments.

/Thomas


> On 14/11/2021 11:12, Thomas Hellström wrote:
>> Don't wait sync while migrating, but rather make the GPU blit await the
>> dependencies and add a moving fence to the object.
>>
>> This also enables asynchronous VRAM management in that on eviction,
>> rather than waiting for the moving fence to expire before freeing VRAM,
>> it is freed immediately and the fence is stored with the VRAM manager 
>> and
>> handed out to newly allocated objects to await before clears and 
>> swapins,
>> or for kernel objects before setting up gpu vmas or mapping.
>>
>> To collect dependencies before migrating, add a set of utilities that
>> coalesce these to a single dma_fence.
>>
>> What is still missing for fully asynchronous operation is 
>> asynchronous vma
>> unbinding, which is still to be implemented.
>>
>> This commit substantially reduces execution time in the 
>> gem_lmem_swapping
>> test.
>>
>> v2:
>> - Make a couple of functions static.