[PATCH v5 0/5] drm/ttm,amdgpu: Introduce LRU bulk move functionality

[Christian König]

Please commit patches #1, #2 and #3, doesn't make much sense to send 
them out even more often.

Jerry's comments on patch #4 sound valid to me as well, but with those 
minor issues fixes/commented I think we can commit it.

Thanks for taking care of this,
Christian.

Am 22.08.2018 um 09:52 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:
> Commit 0bbf32026cf5ba41e9922b30e26e1bed1ecd38ae ("drm/amdgpu: band aid
> validating VM PTs")
>
> 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.
>
> Changes from V3 -> V4:
> - Move the amdgpu_vm_move_to_lru_tail after command submission, at that time,
>    all bo will be back on idle list.
>
> Changes from V4 -> V5:
> - Remove amdgpu_vm_move_to_lru_tail_by_list(), use bulk_moveable instread of
>    validated, and move ttm_bo_bulk_move_lru_tail() also into
>    amdgpu_vm_move_to_lru_tail().
>
> Thanks,
> Ray
>
> 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 (v5)
>    drm/amdgpu: move PD/PT bos on LRU again
>
>   drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 10 +++++
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 68 +++++++++++++++++++----------
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h | 11 ++++-
>   drivers/gpu/drm/ttm/ttm_bo.c           | 78 +++++++++++++++++++++++++++++++++-
>   include/drm/ttm/ttm_bo_api.h           | 16 ++++++-
>   include/drm/ttm/ttm_bo_driver.h        | 28 ++++++++++++
>   6 files changed, 186 insertions(+), 25 deletions(-)
>