Re: [PATCH 2/3] drm/amdgpu: separate per VM BOs from normal in the moved state

Zhang, Jerry (Junwei)
2018-09-03T02:52:21Z

> Allows us to avoid taking the spinlock in more places.
>
> Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Junwei Zhang <Jerry.Zhang@amd.com>

> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 67 +++++++++++++++++-----------------
> drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h | 7 +++-
> 2 files changed, 38 insertions(+), 36 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> index a9275a99d793..65977e7c94dc 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> @@ -342,9 +342,7 @@ int amdgpu_vm_validate_pt_bos(struct amdgpu_device *adev, struct amdgpu_vm *vm,
> break;
>
> if (bo->tbo.type != ttm_bo_type_kernel) {
> - spin_lock(&vm->moved_lock);
> list_move(&bo_base->vm_status, &vm->moved);
> - spin_unlock(&vm->moved_lock);
> } else {
> if (vm->use_cpu_for_update)
> r = amdgpu_bo_kmap(bo, NULL);
> @@ -1734,10 +1732,6 @@ int amdgpu_vm_bo_update(struct amdgpu_device *adev,
> amdgpu_asic_flush_hdp(adev, NULL);
> }
>
> - spin_lock(&vm->moved_lock);
> - list_del_init(&bo_va->base.vm_status);
> - spin_unlock(&vm->moved_lock);
> -
> /* If the BO is not in its preferred location add it back to
> * the evicted list so that it gets validated again on the
> * next command submission.
> @@ -1746,9 +1740,13 @@ int amdgpu_vm_bo_update(struct amdgpu_device *adev,
> uint32_t mem_type = bo->tbo.mem.mem_type;
>
> if (!(bo->preferred_domains & amdgpu_mem_type_to_domain(mem_type)))
> - list_add_tail(&bo_va->base.vm_status, &vm->evicted);
> + list_move_tail(&bo_va->base.vm_status, &vm->evicted);
> else
> - list_add(&bo_va->base.vm_status, &vm->idle);
> + list_move(&bo_va->base.vm_status, &vm->idle);
> + } else {
> + spin_lock(&vm->invalidated_lock);
> + list_del_init(&bo_va->base.vm_status);
> + spin_unlock(&vm->invalidated_lock);
> }
>
> list_splice_init(&bo_va->invalids, &bo_va->valids);
> @@ -1974,40 +1972,40 @@ int amdgpu_vm_handle_moved(struct amdgpu_device *adev,
> struct amdgpu_vm *vm)
> {
> struct amdgpu_bo_va *bo_va, *tmp;
> - struct list_head moved;
> + struct reservation_object *resv;
> bool clear;
> int r;
>
> - INIT_LIST_HEAD(&moved);
> - spin_lock(&vm->moved_lock);
> - list_splice_init(&vm->moved, &moved);
> - spin_unlock(&vm->moved_lock);
> + list_for_each_entry_safe(bo_va, tmp, &vm->moved, base.vm_status) {
> + /* Per VM BOs never need to bo cleared in the page tables */
> + r = amdgpu_vm_bo_update(adev, bo_va, false);
> + if (r)
> + return r;
> + }
>
> - list_for_each_entry_safe(bo_va, tmp, &moved, base.vm_status) {
> - struct reservation_object *resv = bo_va->base.bo->tbo.resv;
> + spin_lock(&vm->invalidated_lock);
> + while (!list_empty(&vm->invalidated)) {
> + bo_va = list_first_entry(&vm->invalidated, struct amdgpu_bo_va,
> + base.vm_status);
> + resv = bo_va->base.bo->tbo.resv;
> + spin_unlock(&vm->invalidated_lock);
>
> - /* Per VM BOs never need to bo cleared in the page tables */
> - if (resv == vm->root.base.bo->tbo.resv)
> - clear = false;
> /* Try to reserve the BO to avoid clearing its ptes */
> - else if (!amdgpu_vm_debug && reservation_object_trylock(resv))
> + if (!amdgpu_vm_debug && reservation_object_trylock(resv))
> clear = false;
> /* Somebody else is using the BO right now */
> else
> clear = true;
>
> r = amdgpu_vm_bo_update(adev, bo_va, clear);
> - if (r) {
> - spin_lock(&vm->moved_lock);
> - list_splice(&moved, &vm->moved);
> - spin_unlock(&vm->moved_lock);
> + if (r)
> return r;
> - }
>
> - if (!clear && resv != vm->root.base.bo->tbo.resv)
> + if (!clear)
> reservation_object_unlock(resv);
> -
> + spin_lock(&vm->invalidated_lock);
> }
> + spin_unlock(&vm->invalidated_lock);
>
> return 0;
> }
> @@ -2072,9 +2070,7 @@ static void amdgpu_vm_bo_insert_map(struct amdgpu_device *adev,
>
> if (bo && bo->tbo.resv == vm->root.base.bo->tbo.resv &&
> !bo_va->base.moved) {
> - spin_lock(&vm->moved_lock);
> list_move(&bo_va->base.vm_status, &vm->moved);
> - spin_unlock(&vm->moved_lock);
> }
> trace_amdgpu_vm_bo_map(bo_va, mapping);
> }
> @@ -2430,9 +2426,9 @@ void amdgpu_vm_bo_rmv(struct amdgpu_device *adev,
>
> list_del(&bo_va->base.bo_list);
>
> - spin_lock(&vm->moved_lock);
> + spin_lock(&vm->invalidated_lock);
> list_del(&bo_va->base.vm_status);
> - spin_unlock(&vm->moved_lock);
> + spin_unlock(&vm->invalidated_lock);
>
> list_for_each_entry_safe(mapping, next, &bo_va->valids, list) {
> list_del(&mapping->list);
> @@ -2489,10 +2485,12 @@ void amdgpu_vm_bo_invalidate(struct amdgpu_device *adev,
>
> if (bo->tbo.type == ttm_bo_type_kernel) {
> list_move(&bo_base->vm_status, &vm->relocated);
> - } else {
> - spin_lock(&bo_base->vm->moved_lock);
> + } else if (bo->tbo.resv == vm->root.base.bo->tbo.resv) {
> list_move(&bo_base->vm_status, &vm->moved);
> - spin_unlock(&bo_base->vm->moved_lock);
> + } else {
> + spin_lock(&vm->invalidated_lock);
> + list_move(&bo_base->vm_status, &vm->invalidated);
> + spin_unlock(&vm->invalidated_lock);
> }
> }
> }
> @@ -2637,9 +2635,10 @@ int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm,
> vm->reserved_vmid[i] = NULL;
> INIT_LIST_HEAD(&vm->evicted);
> INIT_LIST_HEAD(&vm->relocated);
> - spin_lock_init(&vm->moved_lock);
> INIT_LIST_HEAD(&vm->moved);
> INIT_LIST_HEAD(&vm->idle);
> + INIT_LIST_HEAD(&vm->invalidated);
> + spin_lock_init(&vm->invalidated_lock);
> INIT_LIST_HEAD(&vm->freed);
>
> /* create scheduler entity for page table updates */
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
> index 62116fa44718..6ea162ca296a 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
> @@ -201,13 +201,16 @@ struct amdgpu_vm {
> /* PT BOs which relocated and their parent need an update */
> struct list_head relocated;
>
> - /* BOs moved, but not yet updated in the PT */
> + /* per VM BOs moved, but not yet updated in the PT */
> struct list_head moved;
> - spinlock_t moved_lock;
>
> /* All BOs of this VM not currently in the state machine */
> struct list_head idle;
>
> + /* regular invalidated BOs, but not yet updated in the PT */
> + struct list_head invalidated;
> + spinlock_t invalidated_lock;
> +
> /* BO mappings freed, but not yet updated in the PT */
> struct list_head freed;