drm/amdgpu: use only one reservation object for each VM v2

Reduces the locking and fencing overhead.

v2: add comment why we need the duplicates list in the GEM op.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Jammy Zhou <Jammy.Zhou@amd.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
index b75c3b235832..2f39fea10bd1 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
@@ -455,11 +455,12 @@ static void amdgpu_gem_va_update_vm(struct amdgpu_device *adev,
         struct ttm_validate_buffer tv, *entry;
         struct amdgpu_bo_list_entry *vm_bos;
         struct ww_acquire_ctx ticket;
-        struct list_head list;
+        struct list_head list, duplicates;
         unsigned domain;
         int r;
 
         INIT_LIST_HEAD(&list);
+        INIT_LIST_HEAD(&duplicates);
 
         tv.bo = &bo_va->bo->tbo;
         tv.shared = true;
@@ -469,7 +470,8 @@ static void amdgpu_gem_va_update_vm(struct amdgpu_device *adev,
         if (!vm_bos)
                 return;
 
-        r = ttm_eu_reserve_buffers(&ticket, &list, true, NULL);
+        /* Provide duplicates to avoid -EALREADY */
+        r = ttm_eu_reserve_buffers(&ticket, &list, true, &duplicates);
         if (r)
                 goto error_free;