Re: [PATCH 10/11] drm/i915: Mark the context and address space as closed

Tvrtko Ursulin
2015-12-17T12:37:15Z

Hi,

On 14/12/15 11:36, Chris Wilson wrote:
> When the user closes the context mark it and the dependent address space
> as closed. As we use an asynchronous destruct method, this has two purposes.
> First it allows us to flag the closed context and detect internal errors if
> we to create any new objects for it (as it is removed from the user's
> namespace, these should be internal bugs only). And secondly, it allows
> us to immediately reap stale vma.
>
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> ---
> drivers/gpu/drm/i915/i915_drv.h | 4 ++++
> drivers/gpu/drm/i915/i915_gem.c | 15 ++++++++-----
> drivers/gpu/drm/i915/i915_gem_context.c | 39 +++++++++++++++++++++++++++++----
> drivers/gpu/drm/i915/i915_gem_gtt.c | 11 +++++++---
> drivers/gpu/drm/i915/i915_gem_gtt.h | 9 ++++++++
> drivers/gpu/drm/i915/i915_gem_stolen.c | 2 +-
> 6 files changed, 66 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 696469a06715..66ecd6b3df95 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -892,6 +892,8 @@ struct intel_context {
> } engine[I915_NUM_RINGS];
>
> struct list_head link;
> +
> + bool closed:1;
> };
>
> enum fb_op_origin {
> @@ -2720,6 +2722,8 @@ int __must_check i915_vma_unbind(struct i915_vma *vma);
> * _guarantee_ VMA in question is _not in use_ anywhere.
> */
> int __must_check __i915_vma_unbind_no_wait(struct i915_vma *vma);
> +void i915_vma_close(struct i915_vma *vma);
> +
> int i915_gem_object_put_pages(struct drm_i915_gem_object *obj);
> void i915_gem_release_all_mmaps(struct drm_i915_private *dev_priv);
> void i915_gem_release_mmap(struct drm_i915_gem_object *obj);
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 7c13c27a6470..08ea0b7eda8b 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -2367,12 +2367,13 @@ i915_gem_object_flush_active(struct drm_i915_gem_object *obj)
> return 0;
> }
>
> -static void i915_vma_close(struct i915_vma *vma)

Can't find this in this series?

> +void i915_vma_close(struct i915_vma *vma)
> {
> RQ_BUG_ON(vma->closed);
> vma->closed = true;
>
> list_del_init(&vma->obj_link);
> + list_del_init(&vma->vm_link);
> if (!vma->active)
> WARN_ON(i915_vma_unbind(vma));
> }
> @@ -2620,12 +2621,13 @@ static int __i915_vma_unbind(struct i915_vma *vma, bool wait)
> return ret;
> }
>
> - trace_i915_vma_unbind(vma);
> -
> - vma->vm->unbind_vma(vma);
> + if (likely(!vma->vm->closed)) {
> + trace_i915_vma_unbind(vma);
> + vma->vm->unbind_vma(vma);
> + }
> vma->bound = 0;
>
> - list_del_init(&vma->vm_link);
> + list_move_tail(&vma->vm_link, &vma->vm->unbound_list);
> if (vma->is_ggtt) {
> if (vma->ggtt_view.type == I915_GGTT_VIEW_NORMAL) {
> obj->map_and_fenceable = false;
> @@ -2882,7 +2884,7 @@ search_free:
> goto err_remove_node;
>
> list_move_tail(&obj->global_list, &dev_priv->mm.bound_list);
> - list_add_tail(&vma->vm_link, &vm->inactive_list);
> + list_move_tail(&vma->vm_link, &vm->inactive_list);
>
> return vma;
>
> @@ -3890,6 +3892,7 @@ void i915_gem_vma_destroy(struct i915_vma *vma)
> if (!list_empty(&vma->exec_list))
> return;
>
> + list_del(&vma->vm_link);
> if (!vma->is_ggtt)
> i915_ppgtt_put(i915_vm_to_ppgtt(vma->vm));
>
> diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
> index c4a8a64cd1b2..9669547c7c2d 100644
> --- a/drivers/gpu/drm/i915/i915_gem_context.c
> +++ b/drivers/gpu/drm/i915/i915_gem_context.c
> @@ -153,6 +153,7 @@ void i915_gem_context_free(struct kref *ctx_ref)
> struct intel_context *ctx = container_of(ctx_ref, typeof(*ctx), ref);
>
> trace_i915_context_free(ctx);
> + RQ_BUG_ON(!ctx->closed);

Normal BUG_ON I think.

>
> if (i915.enable_execlists)
> intel_lr_context_free(ctx);
> @@ -209,6 +210,36 @@ i915_gem_alloc_context_obj(struct drm_device *dev, size_t size)
> return obj;
> }
>
> +static void i915_ppgtt_close(struct i915_address_space *vm)
> +{
> + struct list_head *phases[] = {
> + &vm->active_list,
> + &vm->inactive_list,
> + &vm->unbound_list,
> + NULL,
> + }, **phase;
> +
> + RQ_BUG_ON(vm->is_ggtt);
> + RQ_BUG_ON(vm->closed);

More, and elsewhere.

> + vm->closed = true;
> +
> + for (phase = phases; *phase; phase++) {
> + struct i915_vma *vma, *vn;
> +
> + list_for_each_entry_safe(vma, vn, *phase, vm_link)
> + i915_vma_close(vma);

Can't really carry on since I don't see the implementation of this.

Does it wait for retirement?

> + }
> +}
> +
> +static void context_close(struct intel_context *ctx)
> +{
> + RQ_BUG_ON(ctx->closed);
> + ctx->closed = true;
> + if (ctx->ppgtt)
> + i915_ppgtt_close(&ctx->ppgtt->base);
> + i915_gem_context_unreference(ctx);
> +}
> +
> static struct intel_context *
> __create_hw_context(struct drm_device *dev,
> struct drm_i915_file_private *file_priv)
> @@ -256,7 +287,7 @@ __create_hw_context(struct drm_device *dev,
> return ctx;
>
> err_out:
> - i915_gem_context_unreference(ctx);
> + context_close(ctx);
> return ERR_PTR(ret);
> }
>
> @@ -318,7 +349,7 @@ err_unpin:
> i915_gem_object_ggtt_unpin(ctx->legacy_hw_ctx.rcs_state);
> err_destroy:
> idr_remove(&file_priv->context_idr, ctx->user_handle);
> - i915_gem_context_unreference(ctx);
> + context_close(ctx);
> return ERR_PTR(ret);
> }
>
> @@ -470,7 +501,7 @@ static int context_idr_cleanup(int id, void *p, void *data)
> {
> struct intel_context *ctx = p;
>
> - i915_gem_context_unreference(ctx);
> + context_close(ctx);
> return 0;
> }
>
> @@ -894,7 +925,7 @@ int i915_gem_context_destroy_ioctl(struct drm_device *dev, void *data,
> }
>
> idr_remove(&ctx->file_priv->context_idr, ctx->user_handle);
> - i915_gem_context_unreference(ctx);
> + context_close(ctx);
> mutex_unlock(&dev->struct_mutex);
>
> DRM_DEBUG_DRIVER("HW context %d destroyed\n", args->ctx_id);
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
> index 9f594c33bd0a..354236d72432 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
> @@ -2130,6 +2130,7 @@ static void i915_address_space_init(struct i915_address_space *vm,
> vm->dev = dev_priv->dev;
> INIT_LIST_HEAD(&vm->active_list);
> INIT_LIST_HEAD(&vm->inactive_list);
> + INIT_LIST_HEAD(&vm->unbound_list);
> list_add_tail(&vm->global_link, &dev_priv->vm_list);
> }
>
> @@ -2214,9 +2215,10 @@ void i915_ppgtt_release(struct kref *kref)
>
> trace_i915_ppgtt_release(&ppgtt->base);
>
> - /* vmas should already be unbound */
> + /* vmas should already be unbound and destroyed */
> WARN_ON(!list_empty(&ppgtt->base.active_list));
> WARN_ON(!list_empty(&ppgtt->base.inactive_list));
> + WARN_ON(!list_empty(&ppgtt->base.unbound_list));
>
> list_del(&ppgtt->base.global_link);
> drm_mm_takedown(&ppgtt->base.mm);
> @@ -2698,7 +2700,7 @@ static int i915_gem_setup_global_gtt(struct drm_device *dev,
> return ret;
> }
> vma->bound |= GLOBAL_BIND;
> - list_add_tail(&vma->vm_link, &ggtt_vm->inactive_list);
> + list_move_tail(&vma->vm_link, &ggtt_vm->inactive_list);
> }
>
> /* Clear any non-preallocated blocks */
> @@ -3252,6 +3254,8 @@ __i915_gem_vma_create(struct drm_i915_gem_object *obj,
> struct i915_vma *vma;
> int i;
>
> + RQ_BUG_ON(vm->closed);
> +
> if (WARN_ON(i915_is_ggtt(vm) != !!ggtt_view))
> return ERR_PTR(-EINVAL);
>
> @@ -3259,11 +3263,11 @@ __i915_gem_vma_create(struct drm_i915_gem_object *obj,
> if (vma == NULL)
> return ERR_PTR(-ENOMEM);
>
> - INIT_LIST_HEAD(&vma->vm_link);
> INIT_LIST_HEAD(&vma->obj_link);
> INIT_LIST_HEAD(&vma->exec_list);
> for (i = 0; i < ARRAY_SIZE(vma->last_read); i++)
> init_request_active(&vma->last_read[i], i915_vma_retire);
> + list_add(&vma->vm_link, &vm->unbound_list);
> vma->vm = vm;
> vma->obj = obj;
> vma->is_ggtt = i915_is_ggtt(vm);
> @@ -3310,6 +3314,7 @@ i915_gem_obj_lookup_or_create_ggtt_vma(struct drm_i915_gem_object *obj,
> if (!vma)
> vma = __i915_gem_vma_create(obj, ggtt, view);
>
> + RQ_BUG_ON(vma->closed);
> return vma;
>
> }
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h
> index be7e8526b219..3bd2a4f4990c 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.h
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
> @@ -284,6 +284,8 @@ struct i915_address_space {
> u64 start; /* Start offset always 0 for dri2 */
> u64 total; /* size addr space maps (ex. 2GB for ggtt) */
>
> + bool closed;
> +
> struct i915_page_scratch *scratch_page;
> struct i915_page_table *scratch_pt;
> struct i915_page_directory *scratch_pd;
> @@ -312,6 +314,13 @@ struct i915_address_space {
> */
> struct list_head inactive_list;
>
> + /**
> + * List of vma that have been unbound.
> + *
> + * A reference is not held on the buffer while on this list.

s/buffer/object/

> + */
> + struct list_head unbound_list;
> +
> /* FIXME: Need a more generic return type */
> gen6_pte_t (*pte_encode)(dma_addr_t addr,
> enum i915_cache_level level,
> diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c
> index 305d58a5f745..4a803311f5bf 100644
> --- a/drivers/gpu/drm/i915/i915_gem_stolen.c
> +++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
> @@ -688,7 +688,7 @@ i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
> }
>
> vma->bound |= GLOBAL_BIND;
> - list_add_tail(&vma->vm_link, &ggtt->inactive_list);
> + list_move_tail(&vma->vm_link, &ggtt->inactive_list);
> }
>
> list_add_tail(&obj->global_list, &dev_priv->mm.bound_list);
>

Regards,

Tvrtko