On Mon, Jul 08, 2013 at 11:08:42PM -0700, Ben Widawsky wrote:
> Probably need to squash whole thing, or just the inactive part, tbd...
>
> Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
I agree that we need vma->active, but I'm not sold on removing
obj->active. Atm we have to use-cases for checking obj->active:
- In the evict/unbind code to check whether the gpu is still using this
specific mapping. This use-case nicely fits into checking vma->active.
- In the shrinker code and everywhere we want to do cpu access we only
care about whether the gpu is accessing the object, not at all through
which mapping precisely. There a vma-independant obj->active sounds much
saner.
Note though that just keeping track of vma->active isn't too useful, since
if some other vma is keeping the object busy we'll still stall on that one
for eviction. So we'd need a vma->ring and vma->last_rendering_seqno, too.
At that point I wonder a bit whether all this complexity is worth it ...
I need to ponder this some more.
-Daniel
> ---
> drivers/gpu/drm/i915/i915_drv.h | 14 ++++++------
> drivers/gpu/drm/i915/i915_gem.c | 47 ++++++++++++++++++++++++-----------------
> 2 files changed, 35 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 38d07f2..e6694ae 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -541,6 +541,13 @@ struct i915_vma {
> struct drm_i915_gem_object *obj;
> struct i915_address_space *vm;
>
> + /**
> + * This is set if the object is on the active lists (has pending
> + * rendering and so a non-zero seqno), and is not set if it i s on
> + * inactive (ready to be unbound) list.
> + */
> + unsigned int active:1;
> +
> /** This object's place on the active/inactive lists */
> struct list_head mm_list;
>
> @@ -1250,13 +1257,6 @@ struct drm_i915_gem_object {
> struct list_head exec_list;
>
> /**
> - * This is set if the object is on the active lists (has pending
> - * rendering and so a non-zero seqno), and is not set if it i s on
> - * inactive (ready to be unbound) list.
> - */
> - unsigned int active:1;
> -
> - /**
> * This is set if the object has been written to since last bound
> * to the GTT
> */
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index c2ecb78..b87073b 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -137,7 +137,13 @@ int i915_mutex_lock_interruptible(struct drm_device *dev)
> /* NB: Not the same as !i915_gem_object_is_inactive */
> bool i915_gem_object_is_active(struct drm_i915_gem_object *obj)
> {
> - return obj->active;
> + struct i915_vma *vma;
> +
> + list_for_each_entry(vma, &obj->vma_list, vma_link)
> + if (vma->active)
> + return true;
> +
> + return false;
> }
>
> static inline bool
> @@ -1899,14 +1905,14 @@ i915_gem_object_move_to_active(struct drm_i915_gem_object *obj,
> BUG_ON(ring == NULL);
> obj->ring = ring;
>
> + /* Move from whatever list we were on to the tail of execution. */
> + vma = i915_gem_obj_to_vma(obj, vm);
> /* Add a reference if we're newly entering the active list. */
> - if (!i915_gem_object_is_active(obj)) {
> + if (!vma->active) {
> drm_gem_object_reference(&obj->base);
> - obj->active = 1;
> + vma->active = 1;
> }
>
> - /* Move from whatever list we were on to the tail of execution. */
> - vma = i915_gem_obj_to_vma(obj, vm);
> list_move_tail(&vma->mm_list, &vm->active_list);
> list_move_tail(&obj->ring_list, &ring->active_list);
>
> @@ -1927,16 +1933,23 @@ i915_gem_object_move_to_active(struct drm_i915_gem_object *obj,
> }
>
> static void
> -i915_gem_object_move_to_inactive(struct drm_i915_gem_object *obj,
> - struct i915_address_space *vm)
> +i915_gem_object_move_to_inactive(struct drm_i915_gem_object *obj)
> {
> + struct drm_i915_private *dev_priv = obj->base.dev->dev_private;
> + struct i915_address_space *vm;
> struct i915_vma *vma;
> + int i = 0;
>
> BUG_ON(obj->base.write_domain & ~I915_GEM_GPU_DOMAINS);
> - BUG_ON(!i915_gem_object_is_active(obj));
>
> - vma = i915_gem_obj_to_vma(obj, vm);
> - list_move_tail(&vma->mm_list, &vm->inactive_list);
> + list_for_each_entry(vm, &dev_priv->vm_list, global_link) {
> + vma = i915_gem_obj_to_vma(obj, vm);
For paranoia we might want to track the vm used to run a batch in it
request struct, then we
> + if (!vma || !vma->active)
> + continue;
> + list_move_tail(&vma->mm_list, &vm->inactive_list);
> + vma->active = 0;
> + i++;
> + }
>
> list_del_init(&obj->ring_list);
> obj->ring = NULL;
> @@ -1948,8 +1961,8 @@ i915_gem_object_move_to_inactive(struct drm_i915_gem_object *obj,
> obj->last_fenced_seqno = 0;
> obj->fenced_gpu_access = false;
>
> - obj->active = 0;
> - drm_gem_object_unreference(&obj->base);
> + while (i--)
> + drm_gem_object_unreference(&obj->base);
>
> WARN_ON(i915_verify_lists(dev));
> }
> @@ -2272,15 +2285,13 @@ static void i915_gem_reset_ring_lists(struct drm_i915_private *dev_priv,
> }
>
> while (!list_empty(&ring->active_list)) {
> - struct i915_address_space *vm;
> struct drm_i915_gem_object *obj;
>
> obj = list_first_entry(&ring->active_list,
> struct drm_i915_gem_object,
> ring_list);
>
> - list_for_each_entry(vm, &dev_priv->vm_list, global_link)
> - i915_gem_object_move_to_inactive(obj, vm);
> + i915_gem_object_move_to_inactive(obj);
> }
> }
>
> @@ -2356,8 +2367,6 @@ i915_gem_retire_requests_ring(struct intel_ring_buffer *ring)
> * by the ringbuffer to the flushing/inactive lists as appropriate.
> */
> while (!list_empty(&ring->active_list)) {
> - struct drm_i915_private *dev_priv = ring->dev->dev_private;
> - struct i915_address_space *vm;
> struct drm_i915_gem_object *obj;
>
> obj = list_first_entry(&ring->active_list,
> @@ -2367,8 +2376,8 @@ i915_gem_retire_requests_ring(struct intel_ring_buffer *ring)
> if (!i915_seqno_passed(seqno, obj->last_read_seqno))
> break;
>
> - list_for_each_entry(vm, &dev_priv->vm_list, global_link)
> - i915_gem_object_move_to_inactive(obj, vm);
> + BUG_ON(!i915_gem_object_is_active(obj));
> + i915_gem_object_move_to_inactive(obj);
> }
>
> if (unlikely(ring->trace_irq_seqno &&
> --
> 1.8.3.2
>
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> Intel-gfx at lists.freedesktop.org
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--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
