The kernel BOs unnecessarily got added to the external objects list of drm_gpuvm, when mapping to GPU, which would have resulted in few extra CPU cycles being spent at the time of job submission as drm_exec_until_all_locked() loop iterates over all external objects.
Kernel BOs are private to a VM and so they share the dma_resv object of the dummy GEM object created for a VM. Use of DRM_EXEC_IGNORE_DUPLICATES flag ensured the recursive locking of the dummy GEM object was ignored. Also no extra space got allocated to add fences to the dma_resv object of dummy GEM object. So no other impact apart from few extra CPU cycles. This commit sets the pointer to dma_resv object of GEM object of kernel BOs before they are mapped to GPU, to prevent them from being added to external objects list. Signed-off-by: Akash Goel <[email protected]> --- drivers/gpu/drm/panthor/panthor_gem.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/panthor/panthor_gem.c b/drivers/gpu/drm/panthor/panthor_gem.c index f369cc3e2a5f..10d255cccc09 100644 --- a/drivers/gpu/drm/panthor/panthor_gem.c +++ b/drivers/gpu/drm/panthor/panthor_gem.c @@ -145,6 +145,9 @@ panthor_kernel_bo_create(struct panthor_device *ptdev, struct panthor_vm *vm, bo = to_panthor_bo(&obj->base); kbo->obj = &obj->base; bo->flags = bo_flags; + bo->exclusive_vm_root_gem = panthor_vm_root_gem(vm); + drm_gem_object_get(bo->exclusive_vm_root_gem); + bo->base.base.resv = bo->exclusive_vm_root_gem->resv; if (vm == panthor_fw_vm(ptdev)) debug_flags |= PANTHOR_DEBUGFS_GEM_USAGE_FLAG_FW_MAPPED; @@ -168,9 +171,6 @@ panthor_kernel_bo_create(struct panthor_device *ptdev, struct panthor_vm *vm, goto err_free_va; kbo->vm = panthor_vm_get(vm); - bo->exclusive_vm_root_gem = panthor_vm_root_gem(vm); - drm_gem_object_get(bo->exclusive_vm_root_gem); - bo->base.base.resv = bo->exclusive_vm_root_gem->resv; return kbo; err_free_va: -- 2.25.1
