Re: [PATCH] drm/amdkfd: Correct the postion of reserve and unreserve memory

[Chen, Xiaogang]

Is it for fixing the issue you mentioned previously " Fix the deadlock 
in svm_range_restore_work"?

Regards

Xiaogang

On 2/20/2025 5:59 AM, Emily Deng wrote:
Call amdgpu_amdkfd_reserve_mem_limit in svm_range_vram_node_new when
creating a new SVM BO. Call amdgpu_amdkfd_unreserve_mem_limit
in svm_range_bo_release when the SVM BO is deleted.

Signed-off-by: Emily Deng <emily.d...@amd.com>
---
  drivers/gpu/drm/amd/amdkfd/kfd_migrate.c | 13 -------------
  drivers/gpu/drm/amd/amdkfd/kfd_svm.c     | 20 ++++++++++++++++++++
  2 files changed, 20 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c 
b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
index 79251f22b702..3bbc69751f7e 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
@@ -514,15 +514,6 @@ svm_migrate_ram_to_vram(struct svm_range *prange, uint32_t 
best_loc,
        start = start_mgr << PAGE_SHIFT;
        end = (last_mgr + 1) << PAGE_SHIFT;
  
-	r = amdgpu_amdkfd_reserve_mem_limit(node->adev,
-                                       prange->npages * PAGE_SIZE,
-                                       KFD_IOC_ALLOC_MEM_FLAGS_VRAM,
-                                       node->xcp ? node->xcp->id : 0);
-       if (r) {
-               dev_dbg(node->adev->dev, "failed to reserve VRAM, r: %ld\n", r);
-               return -ENOSPC;
-       }
-
        r = svm_range_vram_node_new(node, prange, true);
        if (r) {
                dev_dbg(node->adev->dev, "fail %ld to alloc vram\n", r);
@@ -560,10 +551,6 @@ svm_migrate_ram_to_vram(struct svm_range *prange, uint32_t 
best_loc,
        }
  
  out:
-       amdgpu_amdkfd_unreserve_mem_limit(node->adev,
-                                       prange->npages * PAGE_SIZE,
-                                       KFD_IOC_ALLOC_MEM_FLAGS_VRAM,
-                                       node->xcp ? node->xcp->id : 0);
        return r < 0 ? r : 0;
  }
  
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index db3034b00dac..c861d8c90419 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -430,6 +430,10 @@ static void svm_range_bo_release(struct kref *kref)
                /* We're not in the eviction worker. Signal the fence. */
                dma_fence_signal(&svm_bo->eviction_fence->base);
        dma_fence_put(&svm_bo->eviction_fence->base);
+       amdgpu_amdkfd_unreserve_mem_limit(svm_bo->node->adev,
+               svm_bo->bo->tbo.base.size,
+               KFD_IOC_ALLOC_MEM_FLAGS_VRAM,
+               svm_bo->node->xcp ? svm_bo->node->xcp->id : 0);
        amdgpu_bo_unref(&svm_bo->bo);
        kfree(svm_bo);
  }
@@ -581,6 +585,18 @@ svm_range_vram_node_new(struct kfd_node *node, struct 
svm_range *prange,
                kfree(svm_bo);
                return -ESRCH;
        }
+
+       r = amdgpu_amdkfd_reserve_mem_limit(node->adev,
+                       prange->npages * PAGE_SIZE,
+                       KFD_IOC_ALLOC_MEM_FLAGS_VRAM,
+                       node->xcp ? node->xcp->id : 0);
+       if (r) {
+               pr_debug("failed to reserve VRAM, r: %ld\n", r);
+               mmput(mm);
+               kfree(svm_bo);
+               return -ENOSPC;
+       }
+
        svm_bo->node = node;
        svm_bo->eviction_fence =
                amdgpu_amdkfd_fence_create(dma_fence_context_alloc(1),
@@ -655,6 +671,10 @@ svm_range_vram_node_new(struct kfd_node *node, struct 
svm_range *prange,
  reserve_bo_failed:
        amdgpu_bo_unref(&bo);
  create_bo_failed:
+       amdgpu_amdkfd_unreserve_mem_limit(svm_bo->node->adev,
+               prange->npages * PAGE_SIZE,
+               KFD_IOC_ALLOC_MEM_FLAGS_VRAM,
+               node->xcp ? node->xcp->id : 0);
        dma_fence_put(&svm_bo->eviction_fence->base);
        kfree(svm_bo);
        prange->ttm_res = NULL;