[PATCH v3 0/5] drm/ttm,amdgpu: Introduce LRU bulk move functionality

[Dieter Nützel]

For the series

Tested-by: Dieter Nützel <Dieter at nuetzel-hh.de>

on RX580,
amd-staging-drm-next
#5024f8dfe478

Dieter

Am 13.08.2018 11:58, schrieb Huang Rui:
> The idea and proposal is originally from Christian, and I continue to 
> work to
> deliver it.
> 
> Background:
> amdgpu driver will move all PD/PT and PerVM BOs into idle list. Then 
> move all of
> them on the end of LRU list one by one. Thus, that cause so many BOs 
> moved to
> the end of the LRU, and impact performance seriously.
> 
> Then Christian provided a workaround to not move PD/PT BOs on LRU with 
> below
> patch:
> "drm/amdgpu: band aid validating VM PTs"
> Commit 0bbf32026cf5ba41e9922b30e26e1bed1ecd38ae
> 
> However, the final solution should bulk move all PD/PT and PerVM BOs on 
> the LRU
> instead of one by one.
> 
> Whenever amdgpu_vm_validate_pt_bos() is called and we have BOs which 
> need to be
> validated we move all BOs together to the end of the LRU without 
> dropping the
> lock for the LRU.
> 
> While doing so we note the beginning and end of this block in the LRU 
> list.
> 
> Now when amdgpu_vm_validate_pt_bos() is called and we don't have 
> anything to do,
> we don't move every BO one by one, but instead cut the LRU list into 
> pieces so
> that we bulk move everything to the end in just one operation.
> 
> Test data:
> +--------------+-----------------+-----------+---------------------------------------+
> |              |The Talos        |Clpeak(OCL)|BusSpeedReadback(OCL)
>               |
> |              |Principle(Vulkan)|           |
>               |
> +------------------------------------------------------------------------------------+
> |              |                 |           |0.319 ms(1k) 0.314
> ms(2K) 0.308 ms(4K) |
> | Original     |  147.7 FPS      |  76.86 us |0.307 ms(8K) 0.310
> ms(16K)             |
> +------------------------------------------------------------------------------------+
> | Orignial + WA|                 |           |0.254 ms(1K) 0.241
> ms(2K)              |
> |(don't move   |  162.1 FPS      |  42.15 us |0.230 ms(4K) 0.223
> ms(8K) 0.204 ms(16K)|
> |PT BOs on LRU)|                 |           |
>               |
> +------------------------------------------------------------------------------------+
> | Bulk move    |  163.1 FPS      |  40.52 us |0.244 ms(1K) 0.252
> ms(2K) 0.213 ms(4K) |
> |              |                 |           |0.214 ms(8K) 0.225
> ms(16K)             |
> +--------------+-----------------+-----------+---------------------------------------+
> 
> After test them with above three benchmarks include vulkan and opencl. 
> We can
> see the visible improvement than original, and even better than 
> original with
> workaround.
> 
> Changes from V1 -> V2:
> - Fix to missed the BOs in relocated/moved that should be also moved to 
> the end
>   of LRU.
> 
> Changes from V2 -> V3:
> - Remove unused parameter and use list_for_each_entry instead of the 
> one with
>   save entry.
> 
> Thanks,
> Rui
> 
> Christian König (2):
>   drm/ttm: add helper structures for bulk moves on lru list
>   drm/ttm: revise ttm_bo_move_to_lru_tail to support bulk moves
> 
> Huang Rui (3):
>   drm/ttm: add bulk move function on LRU
>   drm/amdgpu: use bulk moves for efficient VM LRU handling (v3)
>   drm/amdgpu: move PD/PT bos on LRU again
> 
>  drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 75 
> ++++++++++++++++++++++++--------
>  drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h |  4 ++
>  drivers/gpu/drm/ttm/ttm_bo.c           | 78 
> +++++++++++++++++++++++++++++++++-
>  include/drm/ttm/ttm_bo_api.h           | 16 ++++++-
>  include/drm/ttm/ttm_bo_driver.h        | 28 ++++++++++++
>  5 files changed, 182 insertions(+), 19 deletions(-)