[RFC PATCH 128/162] drm/i915/dg1: intel_memory_region_evict() changes for eviction

Matthew Auld matthew.auld at intel.com
Fri Nov 27 12:06:44 UTC 2020


From: CQ Tang <cq.tang at intel.com>

Function i915_gem_shrink_memory_region() is changed to
intel_memory_region_evict() and moved from i915_gem_shrinker.c
to intel_memory_region.c, this function is used to handle local
memory swapping, in addition to evict purgeable objects only.

When an object is selected from list, i915_gem_object_unbind()
might fail if the object vma is pinned, this causes an error
-EBUSY is returned from this function.

The new code uses similar logic as function i915_gem_shrink().

Signed-off-by: CQ Tang <cq.tang at intel.com>
---
 .../gpu/drm/i915/gem/i915_gem_object_types.h  |  1 -
 drivers/gpu/drm/i915/gem/i915_gem_shrinker.c  | 58 -----------
 drivers/gpu/drm/i915/gem/i915_gem_shrinker.h  |  2 -
 drivers/gpu/drm/i915/i915_gem.c               |  8 +-
 drivers/gpu/drm/i915/intel_memory_region.c    | 95 +++++++++++++++++--
 .../drm/i915/selftests/intel_memory_region.c  |  3 +-
 6 files changed, 94 insertions(+), 73 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
index 8d639509b78b..517a606ade8d 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
@@ -237,7 +237,6 @@ struct drm_i915_gem_object {
 		 * region->obj_lock.
 		 */
 		struct list_head region_link;
-		struct list_head tmp_link;
 
 		struct sg_table *pages;
 		void *mapping;
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c b/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c
index 4d346df8fd5b..27674048f17d 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c
@@ -272,64 +272,6 @@ unsigned long i915_gem_shrink_all(struct drm_i915_private *i915)
 	return freed;
 }
 
-int i915_gem_shrink_memory_region(struct intel_memory_region *mem,
-				  resource_size_t target)
-{
-	struct drm_i915_private *i915 = mem->i915;
-	struct drm_i915_gem_object *obj;
-	resource_size_t purged;
-	LIST_HEAD(purgeable);
-	int err = -ENOSPC;
-
-	intel_gt_retire_requests(&i915->gt);
-
-	purged = 0;
-
-	mutex_lock(&mem->objects.lock);
-
-	while ((obj = list_first_entry_or_null(&mem->objects.purgeable,
-					       typeof(*obj),
-					       mm.region_link))) {
-		list_move_tail(&obj->mm.region_link, &purgeable);
-
-		if (!i915_gem_object_has_pages(obj))
-			continue;
-
-		if (i915_gem_object_is_framebuffer(obj))
-			continue;
-
-		if (!kref_get_unless_zero(&obj->base.refcount))
-			continue;
-
-		mutex_unlock(&mem->objects.lock);
-
-		if (!i915_gem_object_unbind(obj, I915_GEM_OBJECT_UNBIND_ACTIVE)) {
-			if (i915_gem_object_trylock(obj)) {
-				__i915_gem_object_put_pages(obj);
-				if (!i915_gem_object_has_pages(obj)) {
-					purged += obj->base.size;
-					if (!i915_gem_object_is_volatile(obj))
-						obj->mm.madv = __I915_MADV_PURGED;
-				}
-				i915_gem_object_unlock(obj);
-			}
-		}
-
-		i915_gem_object_put(obj);
-
-		mutex_lock(&mem->objects.lock);
-
-		if (purged >= target) {
-			err = 0;
-			break;
-		}
-	}
-
-	list_splice_tail(&purgeable, &mem->objects.purgeable);
-	mutex_unlock(&mem->objects.lock);
-	return err;
-}
-
 static unsigned long
 i915_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc)
 {
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shrinker.h b/drivers/gpu/drm/i915/gem/i915_gem_shrinker.h
index c945f3b587d6..7c1e648a8b44 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_shrinker.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_shrinker.h
@@ -31,7 +31,5 @@ void i915_gem_driver_register__shrinker(struct drm_i915_private *i915);
 void i915_gem_driver_unregister__shrinker(struct drm_i915_private *i915);
 void i915_gem_shrinker_taints_mutex(struct drm_i915_private *i915,
 				    struct mutex *mutex);
-int i915_gem_shrink_memory_region(struct intel_memory_region *mem,
-				  resource_size_t target);
 
 #endif /* __I915_GEM_SHRINKER_H__ */
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index bf67f323a1ae..85cbdb8e2bb8 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1008,12 +1008,12 @@ i915_gem_madvise_ioctl(struct drm_device *dev, void *data,
 
 		switch (obj->mm.madv) {
 		case I915_MADV_WILLNEED:
-			list_move(&obj->mm.region_link,
-				  &obj->mm.region->objects.list);
+			list_move_tail(&obj->mm.region_link,
+				       &obj->mm.region->objects.list);
 			break;
 		default:
-			list_move(&obj->mm.region_link,
-				  &obj->mm.region->objects.purgeable);
+			list_move_tail(&obj->mm.region_link,
+				       &obj->mm.region->objects.purgeable);
 			break;
 		}
 
diff --git a/drivers/gpu/drm/i915/intel_memory_region.c b/drivers/gpu/drm/i915/intel_memory_region.c
index 371cd88ff6d8..185eab497803 100644
--- a/drivers/gpu/drm/i915/intel_memory_region.c
+++ b/drivers/gpu/drm/i915/intel_memory_region.c
@@ -3,6 +3,7 @@
  * Copyright © 2019 Intel Corporation
  */
 
+#include "gt/intel_gt_requests.h"
 #include "intel_memory_region.h"
 #include "i915_drv.h"
 
@@ -94,6 +95,90 @@ __intel_memory_region_put_block_buddy(struct i915_buddy_block *block)
 	__intel_memory_region_put_pages_buddy(block->private, &blocks);
 }
 
+static int intel_memory_region_evict(struct intel_memory_region *mem,
+				     resource_size_t target)
+{
+	struct drm_i915_private *i915 = mem->i915;
+	struct list_head still_in_list;
+	struct drm_i915_gem_object *obj;
+	struct list_head *phases[] = {
+		&mem->objects.purgeable,
+		&mem->objects.list,
+		NULL,
+	};
+	struct list_head **phase;
+	resource_size_t found;
+	int pass;
+
+	intel_gt_retire_requests(&i915->gt);
+
+	found = 0;
+	pass = 0;
+	phase = phases;
+
+next:
+	INIT_LIST_HEAD(&still_in_list);
+	mutex_lock(&mem->objects.lock);
+
+	while (found < target &&
+		(obj = list_first_entry_or_null(*phase,
+						typeof(*obj),
+						mm.region_link))) {
+		list_move_tail(&obj->mm.region_link, &still_in_list);
+
+		if (!i915_gem_object_has_pages(obj))
+			continue;
+
+		if (i915_gem_object_is_framebuffer(obj))
+			continue;
+
+		/*
+		 * For IOMEM region, only swap user space objects.
+		 * kernel objects are bound and causes a lot of unbind
+		 * warning message in driver.
+		 * FIXME: swap kernel object as well.
+		 */
+		if (i915_gem_object_type_has(obj, I915_GEM_OBJECT_HAS_IOMEM)
+		    && !obj->base.handle_count)
+			continue;
+
+		if (!kref_get_unless_zero(&obj->base.refcount))
+			continue;
+
+		mutex_unlock(&mem->objects.lock);
+
+		if (!i915_gem_object_unbind(obj, I915_GEM_OBJECT_UNBIND_ACTIVE)) {
+			if (i915_gem_object_trylock(obj)) {
+				__i915_gem_object_put_pages(obj);
+				/* May arrive from get_pages on another bo */
+				if (!i915_gem_object_has_pages(obj)) {
+					found += obj->base.size;
+					if (obj->mm.madv == I915_MADV_DONTNEED)
+						obj->mm.madv = __I915_MADV_PURGED;
+				}
+				i915_gem_object_unlock(obj);
+			}
+		}
+
+		i915_gem_object_put(obj);
+		mutex_lock(&mem->objects.lock);
+
+		if (found >= target)
+			break;
+	}
+	list_splice_tail(&still_in_list, *phase);
+	mutex_unlock(&mem->objects.lock);
+
+	if (found < target) {
+		pass++;
+		phase++;
+		if (*phase)
+			goto next;
+	}
+
+	return (found < target) ? -ENOSPC : 0;
+}
+
 int
 __intel_memory_region_get_pages_buddy(struct intel_memory_region *mem,
 				      resource_size_t size,
@@ -137,7 +222,7 @@ __intel_memory_region_get_pages_buddy(struct intel_memory_region *mem,
 	do {
 		struct i915_buddy_block *block;
 		unsigned int order;
-		bool retry = true;
+
 retry:
 		order = min_t(u32, (fls(n_pages) - 1), max_order);
 		GEM_BUG_ON(order > mem->mm.max_order);
@@ -152,19 +237,15 @@ __intel_memory_region_get_pages_buddy(struct intel_memory_region *mem,
 				resource_size_t target;
 				int err;
 
-				if (!retry)
-					goto err_free_blocks;
-
 				target = n_pages * mem->mm.chunk_size;
 
 				mutex_unlock(&mem->mm_lock);
-				err = i915_gem_shrink_memory_region(mem,
-								    target);
+				err = intel_memory_region_evict(mem,
+								target);
 				mutex_lock(&mem->mm_lock);
 				if (err)
 					goto err_free_blocks;
 
-				retry = false;
 				goto retry;
 			}
 		} while (1);
diff --git a/drivers/gpu/drm/i915/selftests/intel_memory_region.c b/drivers/gpu/drm/i915/selftests/intel_memory_region.c
index 9df0a4f657c1..4b007ed48d2f 100644
--- a/drivers/gpu/drm/i915/selftests/intel_memory_region.c
+++ b/drivers/gpu/drm/i915/selftests/intel_memory_region.c
@@ -1093,7 +1093,8 @@ static void igt_mark_evictable(struct drm_i915_gem_object *obj)
 {
 	i915_gem_object_unpin_pages(obj);
 	obj->mm.madv = I915_MADV_DONTNEED;
-	list_move(&obj->mm.region_link, &obj->mm.region->objects.purgeable);
+	list_move_tail(&obj->mm.region_link,
+		       &obj->mm.region->objects.purgeable);
 }
 
 static int igt_mock_shrink(void *arg)
-- 
2.26.2



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