Re: [Intel-gfx] [PATCH v4 01/38] drm/i915: Use the MRU stack search after evicting

On Thu, Dec 22, 2016 at 08:36:04AM +0000, Chris Wilson wrote:

When we evict from the GTT to make room for an object, the hole we create is put onto the MRU stack inside the drm_mm range manager. On the next search pass, we can speed up a PIN_HIGH allocation by referencing that stack for the new hole.

v2: Pull together the 3 identical implements (ahem, a couple were outdated) into a common routine for allocating a node and evicting as necessary.

Signed-off-by: Chris Wilson chris@chris-wilson.co.uk Reviewed-by: Joonas Lahtinen joonas.lahtinen@linux.intel.com

Since it doesn't apply directly to drm-misc I'm leaving this one out for now. I guess best to merge through drm-intel? -Daniel

---

drivers/gpu/drm/i915/gvt/aperture_gm.c | 33 +++++----------- drivers/gpu/drm/i915/i915_gem_gtt.c | 72 ++++++++++++++++++++++++---------- drivers/gpu/drm/i915/i915_gem_gtt.h | 5 +++ drivers/gpu/drm/i915/i915_vma.c | 40 ++----------------- 4 files changed, 70 insertions(+), 80 deletions(-)

diff --git a/drivers/gpu/drm/i915/gvt/aperture_gm.c b/drivers/gpu/drm/i915/gvt/aperture_gm.c index 7d33b607bc89..1bb7a5b80d47 100644 --- a/drivers/gpu/drm/i915/gvt/aperture_gm.c +++ b/drivers/gpu/drm/i915/gvt/aperture_gm.c @@ -48,47 +48,34 @@ static int alloc_gm(struct intel_vgpu *vgpu, bool high_gm) { struct intel_gvt *gvt = vgpu->gvt; struct drm_i915_private *dev_priv = gvt->dev_priv;

• u32 alloc_flag, search_flag;

• unsigned int flags; u64 start, end, size; struct drm_mm_node *node;

• int retried = 0; int ret;

  if (high_gm) {

• search_flag = DRM_MM_SEARCH_BELOW;
  

• alloc_flag = DRM_MM_CREATE_TOP;
  

  node = &vgpu->gm.high_gm_node; size = vgpu_hidden_sz(vgpu); start = gvt_hidden_gmadr_base(gvt); end = gvt_hidden_gmadr_end(gvt);

• flags = PIN_HIGH;
  

  } else {

• search_flag = DRM_MM_SEARCH_DEFAULT;
  

• alloc_flag = DRM_MM_CREATE_DEFAULT;
  

  node = &vgpu->gm.low_gm_node; size = vgpu_aperture_sz(vgpu); start = gvt_aperture_gmadr_base(gvt); end = gvt_aperture_gmadr_end(gvt);

• flags = PIN_MAPPABLE;
  

  }

  mutex_lock(&dev_priv->drm.struct_mutex);

-search_again:

• ret = drm_mm_insert_node_in_range_generic(&dev_priv->ggtt.base.mm,

• 				  node, size, 4096,
  

• 				  I915_COLOR_UNEVICTABLE,
  

• 				  start, end, search_flag,
  

• 				  alloc_flag);
  

• if (ret) {

• ret = i915_gem_evict_something(&dev_priv->ggtt.base,
  

• 			       size, 4096,
  

• 			       I915_COLOR_UNEVICTABLE,
  

• 			       start, end, 0);
  

• if (ret == 0 && ++retried < 3)
  

• 	goto search_again;
  

• gvt_err("fail to alloc %s gm space from host, retried %d\n",
  

• 		high_gm ? "high" : "low", retried);
  

• }

• ret = i915_gem_gtt_insert(&dev_priv->ggtt.base, node,

• 		  size, 4096, I915_COLOR_UNEVICTABLE,
  

• 		  start, end, flags);
  

  mutex_unlock(&dev_priv->drm.struct_mutex);
• if (ret)

• gvt_err("fail to alloc %s gm space from host\n",
  

• 	high_gm ? "high" : "low");
  

• return ret;

}

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c index 6af9311f72f5..c8f1675852a7 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -2044,7 +2044,6 @@ static int gen6_ppgtt_allocate_page_directories(struct i915_hw_ppgtt *ppgtt) struct i915_address_space *vm = &ppgtt->base; struct drm_i915_private *dev_priv = ppgtt->base.i915; struct i915_ggtt *ggtt = &dev_priv->ggtt;

• bool retried = false; int ret;

  /* PPGTT PDEs reside in the GGTT and consists of 512 entries. The

@@ -2057,29 +2056,14 @@ static int gen6_ppgtt_allocate_page_directories(struct i915_hw_ppgtt *ppgtt) if (ret) return ret;

-alloc:

• ret = drm_mm_insert_node_in_range_generic(&ggtt->base.mm, &ppgtt->node,

• 				  GEN6_PD_SIZE, GEN6_PD_ALIGN,
  

• 				  I915_COLOR_UNEVICTABLE,
  

• 				  0, ggtt->base.total,
  

• 				  DRM_MM_TOPDOWN);
  

• if (ret == -ENOSPC && !retried) {

• ret = i915_gem_evict_something(&ggtt->base,
  

• 			       GEN6_PD_SIZE, GEN6_PD_ALIGN,
  

• 			       I915_COLOR_UNEVICTABLE,
  

• 			       0, ggtt->base.total,
  

• 			       0);
  

• if (ret)
  

• 	goto err_out;
  

• retried = true;
  

• goto alloc;
  

• }

• ret = i915_gem_gtt_insert(&ggtt->base, &ppgtt->node,

• 		  GEN6_PD_SIZE, GEN6_PD_ALIGN,
  

• 		  I915_COLOR_UNEVICTABLE,
  

• 		  0, ggtt->base.total,
  

• 		  PIN_HIGH);
  

  if (ret) goto err_out;

• if (ppgtt->node.start < ggtt->mappable_end) DRM_DEBUG("Forced to use aperture for PDEs\n");

@@ -3553,3 +3537,49 @@ i915_get_ggtt_vma_pages(struct i915_vma *vma) return ret; }

+int i915_gem_gtt_insert(struct i915_address_space *vm,

• 	struct drm_mm_node *node,
  

• 	u64 size, u64 alignment, unsigned long color,
  

• 	u64 start, u64 end, unsigned int flags)
  

+{

• u32 search_flag, alloc_flag;
• int err;
• lockdep_assert_held(&vm->i915->drm.struct_mutex);
• if (flags & PIN_HIGH) {

• search_flag = DRM_MM_SEARCH_BELOW;
  

• alloc_flag = DRM_MM_CREATE_TOP;
  

• } else {

• search_flag = DRM_MM_SEARCH_DEFAULT;
  

• alloc_flag = DRM_MM_CREATE_DEFAULT;
  

• }
• /* We only allocate in PAGE_SIZE/GTT_PAGE_SIZE (4096) chunks,

• * so we know that we always have a minimum alignment of 4096.
  

• * The drm_mm range manager is optimised to return results
  

• * with zero alignment, so where possible use the optimal
  

• * path.
  

• */
  

• GEM_BUG_ON(size & 4095);
• if (alignment <= 4096)

• alignment = 0;
  

• err = drm_mm_insert_node_in_range_generic(&vm->mm, node,

• 				  size, alignment, color,
  

• 				  start, end,
  

• 				  search_flag, alloc_flag);
  

• if (err != -ENOSPC)

• return err;
  

• err = i915_gem_evict_something(vm, size, alignment, color,

• 		       start, end, flags);
  

• if (err)

• return err;
  

• search_flag = DRM_MM_SEARCH_DEFAULT;
• return drm_mm_insert_node_in_range_generic(&vm->mm, node,

• 				   size, alignment, color,
  

• 				   start, end,
  

• 				   search_flag, alloc_flag);
  

+} diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h index 0055b8567a43..4c7bef07e38a 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.h +++ b/drivers/gpu/drm/i915/i915_gem_gtt.h @@ -528,6 +528,11 @@ int __must_check i915_gem_gtt_prepare_pages(struct drm_i915_gem_object *obj, void i915_gem_gtt_finish_pages(struct drm_i915_gem_object *obj, struct sg_table *pages);

+int i915_gem_gtt_insert(struct i915_address_space *vm,

• 	struct drm_mm_node *node,
  

• 	u64 size, u64 alignment, unsigned long color,
  

• 	u64 start, u64 end, unsigned int flags);
  

/* Flags used by pin/bind&friends. */ #define PIN_NONBLOCK BIT(0) #define PIN_MAPPABLE BIT(1) diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c index fd75d5704287..608008d2d999 100644 --- a/drivers/gpu/drm/i915/i915_vma.c +++ b/drivers/gpu/drm/i915/i915_vma.c @@ -415,43 +415,11 @@ i915_vma_insert(struct i915_vma *vma, u64 size, u64 alignment, u64 flags) goto err_unpin; } } else {

• u32 search_flag, alloc_flag;
  

• if (flags & PIN_HIGH) {
  

• 	search_flag = DRM_MM_SEARCH_BELOW;
  

• 	alloc_flag = DRM_MM_CREATE_TOP;
  

• } else {
  

• 	search_flag = DRM_MM_SEARCH_DEFAULT;
  

• 	alloc_flag = DRM_MM_CREATE_DEFAULT;
  

• }
  

• /* We only allocate in PAGE_SIZE/GTT_PAGE_SIZE (4096) chunks,
  

•  * so we know that we always have a minimum alignment of 4096.
  

•  * The drm_mm range manager is optimised to return results
  

•  * with zero alignment, so where possible use the optimal
  

•  * path.
  

•  */
  

• if (alignment <= 4096)
  

• 	alignment = 0;
  

-search_free:

• ret = drm_mm_insert_node_in_range_generic(&vma->vm->mm,
  

• 					  &vma->node,
  

• 					  size, alignment,
  

• 					  obj->cache_level,
  

• 					  start, end,
  

• 					  search_flag,
  

• 					  alloc_flag);
  

• if (ret) {
  

• 	ret = i915_gem_evict_something(vma->vm, size, alignment,
  

• 				       obj->cache_level,
  

• 				       start, end,
  

• 				       flags);
  

• 	if (ret == 0)
  

• 		goto search_free;
  

• ret = i915_gem_gtt_insert(vma->vm, &vma->node,
  

• 			  size, alignment, obj->cache_level,
  

• 			  start, end, flags);
  

• if (ret)
  goto err_unpin;
  

• }
  
  

  GEM_BUG_ON(vma->node.start < start); GEM_BUG_ON(vma->node.start + vma->node.size > end);

-- 2.11.0

---

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