On 2024-04-14 10:57, Arunpravin Paneer
Selvam wrote:
This change will simplify the KFD best effort contiguous VRAM allocation, because KFD doesn't need set new GEM_ flag.Now we have two flags for contiguous VRAM buffer allocation. If the application request for AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS, it would set the ttm place TTM_PL_FLAG_CONTIGUOUS flag in the buffer's placement function. This patch will change the default behaviour of the two flags.
When we set AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS - This means contiguous is not mandatory.
AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS used in couple of places. For
page table BO, it is fine as BO size is page size 4K. For 64KB
reserved BOs and F/W size related BOs, do all allocation happen at
driver initialization before the VRAM is fragmented?
This looks like a bug before, but with this patch, the check makes sense and is needed.- we will try to allocate the contiguous buffer. Say if the allocation fails, we fallback to allocate the individual pages. When we setTTM_PL_FLAG_CONTIGUOUS - This means contiguous allocation is mandatory. - we are setting this in amdgpu_bo_pin_restricted() before bo validation and check this flag in the vram manager file. - if this is set, we should allocate the buffer pages contiguously. the allocation fails, we return -ENOSPC. Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@xxxxxxx> Suggested-by: Christian König <christian.koenig@xxxxxxx> --- drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 14 +++-- drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 57 +++++++++++++++----- 2 files changed, 49 insertions(+), 22 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c index 8bc79924d171..41926d631563 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c @@ -153,8 +153,6 @@ void amdgpu_bo_placement_from_domain(struct amdgpu_bo *abo, u32 domain) else places[c].flags |= TTM_PL_FLAG_TOPDOWN; - if (flags & AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS) - places[c].flags |= TTM_PL_FLAG_CONTIGUOUS; c++; } @@ -899,6 +897,8 @@ int amdgpu_bo_pin_restricted(struct amdgpu_bo *bo, u32 domain, { struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev); struct ttm_operation_ctx ctx = { false, false }; + struct ttm_place *places = bo->placements; + u32 c = 0; int r, i; if (amdgpu_ttm_tt_get_usermm(bo->tbo.ttm)) @@ -921,16 +921,10 @@ int amdgpu_bo_pin_restricted(struct amdgpu_bo *bo, u32 domain, if (bo->tbo.pin_count) { uint32_t mem_type = bo->tbo.resource->mem_type; - uint32_t mem_flags = bo->tbo.resource->placement; if (!(domain & amdgpu_mem_type_to_domain(mem_type))) return -EINVAL; - if ((mem_type == TTM_PL_VRAM) && - (bo->flags & AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS) && - !(mem_flags & TTM_PL_FLAG_CONTIGUOUS)) - return -EINVAL; -
ttm_bo_pin(&bo->tbo);
if (max_offset != 0) {
@@ -968,6 +962,10 @@ int amdgpu_bo_pin_restricted(struct amdgpu_bo *bo, u32 domain,
bo->placements[i].lpfn = lpfn;
}
+ if (domain & AMDGPU_GEM_DOMAIN_VRAM &&
+ !WARN_ON(places[c].mem_type != TTM_PL_VRAM))
+ places[c].flags |= TTM_PL_FLAG_CONTIGUOUS;
+
If BO pinned is not allocated with
AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS, should pin and return scattered
pages because the RDMA support scattered dmabuf. Christian also
pointed this out.
If (bo->flags & AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS &&
bo->placements[i].mem_type == TTM_PL_VRAM)o->placements[i].flags |= TTM_PL_FLAG_CONTIGUOUS;
r = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
if (unlikely(r)) {
dev_err(adev->dev, "%p pin failed\n", bo);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
index 8db880244324..ddbf302878f6 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
@@ -88,6 +88,30 @@ static inline u64 amdgpu_vram_mgr_blocks_size(struct list_head *head)
return size;
}
+static inline unsigned long
+amdgpu_vram_find_pages_per_block(struct ttm_buffer_object *tbo,
+ const struct ttm_place *place,
+ unsigned long bo_flags)
+{
+ unsigned long pages_per_block;
+
+ if (bo_flags & AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS ||
+ place->flags & TTM_PL_FLAG_CONTIGUOUS) {
+ pages_per_block = ~0ul;
+ } else {
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+ pages_per_block = HPAGE_PMD_NR;
+#else
+ /* default to 2MB */
+ pages_per_block = 2UL << (20UL - PAGE_SHIFT);
+#endif
+ pages_per_block = max_t(uint32_t, pages_per_block,
+ tbo->page_alignment);
+ }
+
+ return pages_per_block;
+}
+
/**
* DOC: mem_info_vram_total
*
@@ -451,8 +475,10 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
struct amdgpu_vram_mgr *mgr = to_vram_mgr(man);
struct amdgpu_device *adev = to_amdgpu_device(mgr);
u64 vis_usage = 0, max_bytes, min_block_size;
+ struct amdgpu_bo *bo = ttm_to_amdgpu_bo(tbo);
struct amdgpu_vram_mgr_resource *vres;
u64 size, remaining_size, lpfn, fpfn;
+ unsigned long bo_flags = bo->flags;
struct drm_buddy *mm = &mgr->mm;
struct drm_buddy_block *block;
unsigned long pages_per_block;
@@ -468,18 +494,8 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
if (tbo->type != ttm_bo_type_kernel)
max_bytes -= AMDGPU_VM_RESERVED_VRAM;
- if (place->flags & TTM_PL_FLAG_CONTIGUOUS) {
- pages_per_block = ~0ul;
- } else {
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
- pages_per_block = HPAGE_PMD_NR;
-#else
- /* default to 2MB */
- pages_per_block = 2UL << (20UL - PAGE_SHIFT);
-#endif
- pages_per_block = max_t(uint32_t, pages_per_block,
- tbo->page_alignment);
- }
+ pages_per_block =
+ amdgpu_vram_find_pages_per_block(tbo, place, bo_flags);
vres = kzalloc(sizeof(*vres), GFP_KERNEL);
if (!vres)
@@ -498,7 +514,8 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
if (place->flags & TTM_PL_FLAG_TOPDOWN)
vres->flags |= DRM_BUDDY_TOPDOWN_ALLOCATION;
- if (place->flags & TTM_PL_FLAG_CONTIGUOUS)
+ if (bo_flags & AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS ||
+ place->flags & TTM_PL_FLAG_CONTIGUOUS)
vres->flags |= DRM_BUDDY_CONTIGUOUS_ALLOCATION;
if (fpfn || lpfn != mgr->mm.size)
@@ -529,8 +546,20 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
min_block_size,
&vres->blocks,
vres->flags);
- if (unlikely(r))
+ if (unlikely(r)) {
If pin BO failed to allocate contiguous VRAM, this should return failure to application, as RDMA cannot work with scattered VRAM pages.
Regards,
Philip
+ if (bo_flags & AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS) {
+ /* Fallback to non contiguous allocation */
+ vres->flags &= ~DRM_BUDDY_CONTIGUOUS_ALLOCATION;
+ bo_flags &= ~AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS;
+
+ pages_per_block =
+ amdgpu_vram_find_pages_per_block(tbo,
+ place,
+ bo_flags);
+ continue;
+ }
goto error_free_blocks;
+ }
if (size > remaining_size)
remaining_size = 0;
