[PATCH] drm/amd/amdgpu: decrease ttm bo priority to fix performance drop when VRAM pressure

[Christian König]

Am 27.03.2017 um 14:05 schrieb Roger.He:
> 1. When VRAM pressue and trigger huge evictions there is performance drop,
>     this patch fix it.
> 2. Also reserve priority for KFD using
>
> Change-Id: Idcd2db65be69d62bcbd7dfaa3bcf9bc964d6d122
> Signed-off-by: Roger.He <Hongbo.He at amd.com>

Reviewed-by: Christian König <christian.koenig at amd.com>

> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 4 +---
>   include/drm/ttm/ttm_bo_driver.h            | 2 +-
>   2 files changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> index 434c931..d6b2de9 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> @@ -405,10 +405,8 @@ int amdgpu_bo_create_restricted(struct amdgpu_device *adev,
>   	if (unlikely(r != 0))
>   		return r;
>   
> -	bo->tbo.priority = ilog2(bo->tbo.num_pages);
>   	if (kernel)
> -		bo->tbo.priority *= 2;
> -	bo->tbo.priority = min(bo->tbo.priority, TTM_MAX_BO_PRIORITY - 1);
> +		bo->tbo.priority = 1;
>   
>   	if (flags & AMDGPU_GEM_CREATE_VRAM_CLEARED &&
>   	    bo->tbo.mem.placement & TTM_PL_FLAG_VRAM) {
> diff --git a/include/drm/ttm/ttm_bo_driver.h b/include/drm/ttm/ttm_bo_driver.h
> index c3d74be..7777d14 100644
> --- a/include/drm/ttm/ttm_bo_driver.h
> +++ b/include/drm/ttm/ttm_bo_driver.h
> @@ -42,7 +42,7 @@
>   #include <linux/spinlock.h>
>   #include <linux/reservation.h>
>   
> -#define TTM_MAX_BO_PRIORITY	16U
> +#define TTM_MAX_BO_PRIORITY	4U
>   
>   struct ttm_backend_func {
>   	/**