Re: [PATCH 07/16] drm/i915/vm_bind: Add support to handle object evictions

Matthew Auld <matthew.auld@xxxxxxxxx> · Thu, 29 Sep 2022 18:13:02 +0100

On 28/09/2022 07:19, Niranjana Vishwanathapura wrote:
Support eviction by maintaining a list of evicted persistent vmas
for rebinding during next submission. Ensure the list do not
include persistent vmas that are being purged.

Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@xxxxxxxxx>
Signed-off-by: Andi Shyti <andi.shyti@xxxxxxxxxxxxxxx>

Acked-by: Matthew Auld <matthew.auld@xxxxxxxxx>

---
  .../drm/i915/gem/i915_gem_vm_bind_object.c    |  6 ++++++
  drivers/gpu/drm/i915/gt/intel_gtt.c           |  2 ++
  drivers/gpu/drm/i915/gt/intel_gtt.h           |  4 ++++
  drivers/gpu/drm/i915/i915_vma.c               | 19 +++++++++++++++++++
  drivers/gpu/drm/i915/i915_vma.h               | 10 ++++++++++
  drivers/gpu/drm/i915/i915_vma_types.h         | 10 ++++++++++
  6 files changed, 51 insertions(+)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
index 809c78455d2e..958139ed6da3 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
@@ -85,6 +85,12 @@ static void i915_gem_vm_bind_remove(struct i915_vma *vma, bool release_obj)
  {
  	lockdep_assert_held(&vma->vm->vm_bind_lock);
  
+	spin_lock(&vma->vm->vm_rebind_lock);
+	if (!list_empty(&vma->vm_rebind_link))
+		list_del_init(&vma->vm_rebind_link);
+	i915_vma_set_purged(vma);
+	spin_unlock(&vma->vm->vm_rebind_lock);
+
  	list_del_init(&vma->vm_bind_link);
  	list_del_init(&vma->non_priv_vm_bind_link);
  	i915_vm_bind_it_remove(vma, &vma->vm->va);
diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.c b/drivers/gpu/drm/i915/gt/intel_gtt.c
index da4f9dee0397..6db31197fa87 100644
--- a/drivers/gpu/drm/i915/gt/intel_gtt.c
+++ b/drivers/gpu/drm/i915/gt/intel_gtt.c
@@ -296,6 +296,8 @@ void i915_address_space_init(struct i915_address_space *vm, int subclass)
  	INIT_LIST_HEAD(&vm->non_priv_vm_bind_list);
  	vm->root_obj = i915_gem_object_create_internal(vm->i915, PAGE_SIZE);
  	GEM_BUG_ON(IS_ERR(vm->root_obj));
+	INIT_LIST_HEAD(&vm->vm_rebind_list);
+	spin_lock_init(&vm->vm_rebind_lock);
  }
  
  void *__px_vaddr(struct drm_i915_gem_object *p)
diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.h b/drivers/gpu/drm/i915/gt/intel_gtt.h
index 3f2e87d3bf34..b73d35b4e05d 100644
--- a/drivers/gpu/drm/i915/gt/intel_gtt.h
+++ b/drivers/gpu/drm/i915/gt/intel_gtt.h
@@ -273,6 +273,10 @@ struct i915_address_space {
  	struct list_head vm_bind_list;
  	/** @vm_bound_list: List of vm_binding completed */
  	struct list_head vm_bound_list;
+	/* @vm_rebind_list: list of vmas to be rebinded */
+	struct list_head vm_rebind_list;
+	/* @vm_rebind_lock: protects vm_rebound_list */
+	spinlock_t vm_rebind_lock;
  	/* @va: tree of persistent vmas */
  	struct rb_root_cached va;
  	struct list_head non_priv_vm_bind_list;
diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index 89c276163916..84ed3d1a17a6 100644
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -241,6 +241,7 @@ vma_create(struct drm_i915_gem_object *obj,
  
  	INIT_LIST_HEAD(&vma->vm_bind_link);
  	INIT_LIST_HEAD(&vma->non_priv_vm_bind_link);
+	INIT_LIST_HEAD(&vma->vm_rebind_link);
  	return vma;
  
  err_unlock:
@@ -1686,6 +1687,14 @@ static void force_unbind(struct i915_vma *vma)
  	if (!drm_mm_node_allocated(&vma->node))
  		return;
  
+	/*
+	 * Persistent vma should have been purged by now.
+	 * If not, issue a warning and purge it.
+	 */
+	if (GEM_WARN_ON(i915_vma_is_persistent(vma) &&
+			!i915_vma_is_purged(vma)))
+		i915_vma_set_purged(vma);
+
  	atomic_and(~I915_VMA_PIN_MASK, &vma->flags);
  	WARN_ON(__i915_vma_unbind(vma));
  	GEM_BUG_ON(drm_mm_node_allocated(&vma->node));
@@ -2048,6 +2057,16 @@ int __i915_vma_unbind(struct i915_vma *vma)
  	__i915_vma_evict(vma, false);
  
  	drm_mm_remove_node(&vma->node); /* pairs with i915_vma_release() */
+
+	if (i915_vma_is_persistent(vma)) {
+		spin_lock(&vma->vm->vm_rebind_lock);
+		if (list_empty(&vma->vm_rebind_link) &&
+		    !i915_vma_is_purged(vma))
+			list_add_tail(&vma->vm_rebind_link,
+				      &vma->vm->vm_rebind_list);
+		spin_unlock(&vma->vm->vm_rebind_lock);
+	}
+
  	return 0;
  }
  
diff --git a/drivers/gpu/drm/i915/i915_vma.h b/drivers/gpu/drm/i915/i915_vma.h
index 51e712de380a..48731855b5b0 100644
--- a/drivers/gpu/drm/i915/i915_vma.h
+++ b/drivers/gpu/drm/i915/i915_vma.h
@@ -152,6 +152,16 @@ static inline void i915_vma_set_persistent(struct i915_vma *vma)
  	set_bit(I915_VMA_PERSISTENT_BIT, __i915_vma_flags(vma));
  }
  
+static inline bool i915_vma_is_purged(const struct i915_vma *vma)
+{
+	return test_bit(I915_VMA_PURGED_BIT, __i915_vma_flags(vma));
+}
+
+static inline void i915_vma_set_purged(struct i915_vma *vma)
+{
+	set_bit(I915_VMA_PURGED_BIT, __i915_vma_flags(vma));
+}
+
  static inline struct i915_vma *i915_vma_get(struct i915_vma *vma)
  {
  	i915_gem_object_get(vma->obj);
diff --git a/drivers/gpu/drm/i915/i915_vma_types.h b/drivers/gpu/drm/i915/i915_vma_types.h
index 3d5ffc3e666b..75b8af608ddb 100644
--- a/drivers/gpu/drm/i915/i915_vma_types.h
+++ b/drivers/gpu/drm/i915/i915_vma_types.h
@@ -267,9 +267,17 @@ struct i915_vma {
  /**
   * I915_VMA_PERSISTENT_BIT:
   * The vma is persistent (created with VM_BIND call).
+ *
+ * I915_VMA_PURGED_BIT:
+ * The persistent vma is force unbound either due to VM_UNBIND call
+ * from UMD or VM is released. Do not check/wait for VM activeness
+ * in i915_vma_is_active() and i915_vma_sync() calls.
   */
  #define I915_VMA_PERSISTENT_BIT	19
+#define I915_VMA_PURGED_BIT	20
+
  #define I915_VMA_PERSISTENT	((int)BIT(I915_VMA_PERSISTENT_BIT))
+#define I915_VMA_PURGED		((int)BIT(I915_VMA_PURGED_BIT))
  
  	struct i915_active active;
  
@@ -300,6 +308,8 @@ struct i915_vma {
  	struct list_head vm_bind_link;
  	/* @non_priv_vm_bind_link: Link in non-private persistent VMA list */
  	struct list_head non_priv_vm_bind_link;
+	/* @vm_rebind_link: link to vm_rebind_list and protected by vm_rebind_lock */
+	struct list_head vm_rebind_link; /* Link in vm_rebind_list */
  
  	/** Interval tree structures for persistent vma */
  






