Commit 3d6792cf authored by Chris Wilson's avatar Chris Wilson
Browse files

drm/i915: Forgo last_fence active request tracking 



We were using the last_fence to track the last request that used this
vma that might be interpreted by a fence register and forced ourselves
to wait for this request before modifying any fence register that
overlapped our vma. Due to requirement that we need to track any XY_BLT
command, linear or tiled, this in effect meant that we have to track the
vma for its active lifespan anyway, so we can forgo the explicit
last_fence tracking and just use the whole vma->active.

Another solution would be to pipeline the register updates, and would
help resolve some long running stalls for gen3 (but only gen 2 and 3!)

Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: default avatarMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190812174804.26180-1-chris@chris-wilson.co.uk
parent cf1c97dc

drivers/gpu/drm/i915/i915_debugfs.c

+1 −3
Original line number Diff line number Diff line
@@ -212,9 +212,7 @@ describe_obj(struct seq_file *m, struct drm_i915_gem_object *obj) 
			}

		}

		if (vma->fence)

			seq_printf(m, " , fence: %d%s",

				   vma->fence->id,

				   i915_active_request_isset(&vma->last_fence) ? "*" : "");

			seq_printf(m, " , fence: %d", vma->fence->id);

		seq_puts(m, ")");



		spin_lock(&obj->vma.lock);

drivers/gpu/drm/i915/i915_gem_fence_reg.c

+2 −4
Original line number Diff line number Diff line
@@ -230,16 +230,14 @@ static int fence_update(struct i915_fence_reg *fence, 
			 i915_gem_object_get_tiling(vma->obj)))

			return -EINVAL;



		ret = i915_active_request_retire(&vma->last_fence,

					     &vma->obj->base.dev->struct_mutex);

		ret = i915_active_wait(&vma->active);

		if (ret)

			return ret;

	}



	old = xchg(&fence->vma, NULL);

	if (old) {

		ret = i915_active_request_retire(&old->last_fence,

					     &old->obj->base.dev->struct_mutex);

		ret = i915_active_wait(&old->active);

		if (ret) {

			fence->vma = old;

			return ret;

drivers/gpu/drm/i915/i915_gem_gtt.c

+0 −1
Original line number Diff line number Diff line
@@ -1867,7 +1867,6 @@ static struct i915_vma *pd_vma_create(struct gen6_ppgtt *ppgtt, int size) 
		return ERR_PTR(-ENOMEM);



	i915_active_init(i915, &vma->active, NULL, NULL);

	INIT_ACTIVE_REQUEST(&vma->last_fence);



	vma->vm = &ggtt->vm;

	vma->ops = &pd_vma_ops;

drivers/gpu/drm/i915/i915_vma.c

+0 −13
Original line number Diff line number Diff line
@@ -120,7 +120,6 @@ vma_create(struct drm_i915_gem_object *obj, 


	i915_active_init(vm->i915, &vma->active,

			 __i915_vma_active, __i915_vma_retire);

	INIT_ACTIVE_REQUEST(&vma->last_fence);



	/* Declare ourselves safe for use inside shrinkers */

	if (IS_ENABLED(CONFIG_LOCKDEP)) {
@@ -802,8 +801,6 @@ static void __i915_vma_destroy(struct i915_vma *vma) 
	GEM_BUG_ON(vma->node.allocated);

	GEM_BUG_ON(vma->fence);



	GEM_BUG_ON(i915_active_request_isset(&vma->last_fence));



	mutex_lock(&vma->vm->mutex);

	list_del(&vma->vm_link);

	mutex_unlock(&vma->vm->mutex);
@@ -928,9 +925,6 @@ int i915_vma_move_to_active(struct i915_vma *vma, 
	obj->read_domains |= I915_GEM_GPU_DOMAINS;

	obj->mm.dirty = true;



	if (flags & EXEC_OBJECT_NEEDS_FENCE)

		__i915_active_request_set(&vma->last_fence, rq);



	GEM_BUG_ON(!i915_vma_is_active(vma));

	return 0;

}
@@ -961,14 +955,7 @@ int i915_vma_unbind(struct i915_vma *vma) 
		 * before we are finished).

		 */

		__i915_vma_pin(vma);



		ret = i915_active_wait(&vma->active);

		if (ret)

			goto unpin;



		ret = i915_active_request_retire(&vma->last_fence,

					      &vma->vm->i915->drm.struct_mutex);

unpin:

		__i915_vma_unpin(vma);

		if (ret)

			return ret;

drivers/gpu/drm/i915/i915_vma.h

+0 −1
Original line number Diff line number Diff line
@@ -111,7 +111,6 @@ struct i915_vma { 
#define I915_VMA_GGTT_WRITE	BIT(14)



	struct i915_active active;

	struct i915_active_request last_fence;



	/**

	 * Support different GGTT views into the same object.

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