[PATCH V2] amdgpu: optimization-- reduce noneed mutex_lock area

From: Bernard Zhao
Date: Mon Apr 20 2020 - 22:25:44 EST


Maybe we could reduce the mutex_lock(&mem->lock)`s protected code area,
and noneed to protect pr_debug.

Signed-off-by: Bernard Zhao <bernard@xxxxxxxx>

Changes since V1:
*commit message improve

Link for V1:
*https://lore.kernel.org/patchwork/patch/1226588/
---
drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index 327317c54f7c..3c3769e57174 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -1285,17 +1285,18 @@ int amdgpu_amdkfd_gpuvm_free_memory_of_gpu(
struct bo_vm_reservation_context ctx;
struct ttm_validate_buffer *bo_list_entry;
int ret;
+ unsigned int mapped_to_gpu_memory;

mutex_lock(&mem->lock);
+ mapped_to_gpu_memory = mem->mapped_to_gpu_memory;
+ mutex_unlock(&mem->lock);

- if (mem->mapped_to_gpu_memory > 0) {
+ if (mapped_to_gpu_memory > 0) {
pr_debug("BO VA 0x%llx size 0x%lx is still mapped.\n",
mem->va, bo_size);
- mutex_unlock(&mem->lock);
return -EBUSY;
}

- mutex_unlock(&mem->lock);
/* lock is not needed after this, since mem is unused and will
* be freed anyway
*/
--
2.26.2