winsys/amdgpu: optimize slab allocation for 2 MB amdgpu page tables

- the slab buffer size increased from 128 KB to 2 MB (PTE fragment size)
- the max suballocated buffer size increased from 64 KB to 256 KB,
  this increases memory usage because it wastes memory
- the number of suballocators increased from 1 to 3 and they are layered
  on top of each other to minimize unused space in slabs

The final increase in memory usage is:
  DeusEx:MD:  1.8%
  DOTA 2:     1.75%
  DiRT Rally: 0.2%

The kernel driver will also receive fewer buffers.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/gallium/winsys/amdgpu/drm/amdgpu_winsys.h b/src/gallium/winsys/amdgpu/drm/amdgpu_winsys.h
index fc8f04544a9..5ae1d3e55a3 100644
--- a/src/gallium/winsys/amdgpu/drm/amdgpu_winsys.h
+++ b/src/gallium/winsys/amdgpu/drm/amdgpu_winsys.h
@@ -38,7 +38,7 @@
 
 struct amdgpu_cs;
 
-#define NUM_SLAB_ALLOCATORS 1
+#define NUM_SLAB_ALLOCATORS 3
 
 struct amdgpu_winsys {
    struct radeon_winsys base;