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

[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>
---
 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 {
 	/**
-- 
2.7.4