[PATCH 1/2] drm/amdgpu: group BOs by log2 of the size on the LRU

[Christian König]

Am 14.04.2016 um 16:25 schrieb Christian König:
> Am 14.04.2016 um 16:23 schrieb Alex Deucher:
>> On Thu, Apr 14, 2016 at 8:54 AM, Christian König
>> <deathsimple at vodafone.de> wrote:
>>> From: Christian König <christian.koenig at amd.com>
>>>
>>> This allows us to have small BOs on the LRU before big ones.
>>>
>>> Signed-off-by: Christian König <christian.koenig at amd.com>
>> Have you done any benchmarking to see how much this helps when there
>> is memory contention?
>
> Still working on this. Marek could you help with that? You usually 
> have the Unigin benchmarks ready at hand.

Alex please wait before you merge them. Further testing with Unigin 
Valey showed an interesting bug which needs to be fixed first.

Christian.

>
> Christian.
>
>>
>> For the series:
>> Reviewed-by: Alex Deucher <alexander.deucher at amd.com>
>>
>>> ---
>>>   drivers/gpu/drm/amd/amdgpu/amdgpu.h     | 11 ++++++
>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 59 
>>> +++++++++++++++++++++++++++++++--
>>>   2 files changed, 68 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h 
>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>> index c4a21c6..7b90323 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>> @@ -391,6 +391,14 @@ unsigned amdgpu_fence_count_emitted(struct 
>>> amdgpu_ring *ring);
>>>   /*
>>>    * TTM.
>>>    */
>>> +
>>> +#define AMDGPU_TTM_LRU_SIZE    20
>>> +
>>> +struct amdgpu_mman_lru {
>>> +       struct list_head *lru[TTM_NUM_MEM_TYPES];
>>> +       struct list_head                *swap_lru;
>>> +};
>>> +
>>>   struct amdgpu_mman {
>>>          struct ttm_bo_global_ref        bo_global_ref;
>>>          struct drm_global_reference     mem_global_ref;
>>> @@ -408,6 +416,9 @@ struct amdgpu_mman {
>>>          struct amdgpu_ring *buffer_funcs_ring;
>>>          /* Scheduler entity for buffer moves */
>>>          struct amd_sched_entity                 entity;
>>> +
>>> +       /* custom LRU management */
>>> +       struct amdgpu_mman_lru log2_size[AMDGPU_TTM_LRU_SIZE];
>>>   };
>>>
>>>   int amdgpu_copy_buffer(struct amdgpu_ring *ring,
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c 
>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>>> index fefaa9b..b58a445 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>>> @@ -910,6 +910,50 @@ uint32_t amdgpu_ttm_tt_pte_flags(struct 
>>> amdgpu_device *adev, struct ttm_tt *ttm,
>>>          return flags;
>>>   }
>>>
>>> +static void amdgpu_ttm_lru_removal(struct ttm_buffer_object *tbo)
>>> +{
>>> +       struct amdgpu_device *adev = amdgpu_get_adev(tbo->bdev);
>>> +       unsigned i;
>>> +
>>> +       for (i = 0; i < AMDGPU_TTM_LRU_SIZE; ++i) {
>>> +               struct amdgpu_mman_lru *lru = &adev->mman.log2_size[i];
>>> +
>>> +               if (&tbo->lru == lru->lru[tbo->mem.mem_type])
>>> +                       lru->lru[tbo->mem.mem_type] = tbo->lru.prev;
>>> +
>>> +               if (&tbo->swap == lru->swap_lru)
>>> +                       lru->swap_lru = tbo->swap.prev;
>>> +       }
>>> +}
>>> +
>>> +static struct amdgpu_mman_lru *amdgpu_ttm_lru(struct 
>>> ttm_buffer_object *tbo)
>>> +{
>>> +       struct amdgpu_device *adev = amdgpu_get_adev(tbo->bdev);
>>> +       unsigned log2_size = min(ilog2(tbo->num_pages), 
>>> AMDGPU_TTM_LRU_SIZE);
>>> +
>>> +       return &adev->mman.log2_size[log2_size];
>>> +}
>>> +
>>> +static struct list_head *amdgpu_ttm_lru_tail(struct 
>>> ttm_buffer_object *tbo)
>>> +{
>>> +       struct amdgpu_mman_lru *lru = amdgpu_ttm_lru(tbo);
>>> +       struct list_head *res = lru->lru[tbo->mem.mem_type];
>>> +
>>> +       lru->lru[tbo->mem.mem_type] = &tbo->lru;
>>> +
>>> +       return res;
>>> +}
>>> +
>>> +static struct list_head *amdgpu_ttm_swap_lru_tail(struct 
>>> ttm_buffer_object *tbo)
>>> +{
>>> +       struct amdgpu_mman_lru *lru = amdgpu_ttm_lru(tbo);
>>> +       struct list_head *res = lru->swap_lru;
>>> +
>>> +       lru->swap_lru = &tbo->swap;
>>> +
>>> +       return res;
>>> +}
>>> +
>>>   static struct ttm_bo_driver amdgpu_bo_driver = {
>>>          .ttm_tt_create = &amdgpu_ttm_tt_create,
>>>          .ttm_tt_populate = &amdgpu_ttm_tt_populate,
>>> @@ -923,12 +967,14 @@ static struct ttm_bo_driver amdgpu_bo_driver = {
>>>          .fault_reserve_notify = &amdgpu_bo_fault_reserve_notify,
>>>          .io_mem_reserve = &amdgpu_ttm_io_mem_reserve,
>>>          .io_mem_free = &amdgpu_ttm_io_mem_free,
>>> -       .lru_tail = &ttm_bo_default_lru_tail,
>>> -       .swap_lru_tail = &ttm_bo_default_swap_lru_tail,
>>> +       .lru_removal = &amdgpu_ttm_lru_removal,
>>> +       .lru_tail = &amdgpu_ttm_lru_tail,
>>> +       .swap_lru_tail = &amdgpu_ttm_swap_lru_tail,
>>>   };
>>>
>>>   int amdgpu_ttm_init(struct amdgpu_device *adev)
>>>   {
>>> +       unsigned i, j;
>>>          int r;
>>>
>>>          r = amdgpu_ttm_global_init(adev);
>>> @@ -946,6 +992,15 @@ int amdgpu_ttm_init(struct amdgpu_device *adev)
>>>                  DRM_ERROR("failed initializing buffer object 
>>> driver(%d).\n", r);
>>>                  return r;
>>>          }
>>> +
>>> +       for (i = 0; i < AMDGPU_TTM_LRU_SIZE; ++i) {
>>> +               struct amdgpu_mman_lru *lru = &adev->mman.log2_size[i];
>>> +
>>> +               for (j = 0; j < TTM_NUM_MEM_TYPES; ++j)
>>> +                       lru->lru[j] = &adev->mman.bdev.man[j].lru;
>>> +               lru->swap_lru = &adev->mman.bdev.glob->swap_lru;
>>> +       }
>>> +
>>>          adev->mman.initialized = true;
>>>          r = ttm_bo_init_mm(&adev->mman.bdev, TTM_PL_VRAM,
>>>                                  adev->mc.real_vram_size >> 
>>> PAGE_SHIFT);
>>> -- 
>>> 2.5.0
>>>
>