@@ -668,6 +668,8 @@ struct drm_i915_gem_object {
struct list_head list;
/** This object's place on GPU write list */
struct list_head gpu_write_list;
+ /** This object's place on eviction list */
+ struct list_head evict_list;
/**
* This is set if the object is on the active or flushing lists
@@ -31,167 +31,175 @@
#include "i915_drv.h"
#include "i915_drm.h"
-static inline int
-i915_gem_object_is_purgeable(struct drm_i915_gem_object *obj_priv)
-{
- return obj_priv->madv == I915_MADV_DONTNEED;
-}
-
-static int
-i915_gem_scan_inactive_list_and_evict(struct drm_device *dev, int min_size,
- unsigned alignment, int *found)
+static struct drm_i915_gem_object *
+i915_gem_next_active_object(struct drm_device *dev,
+ struct list_head **render_iter,
+ struct list_head **bsd_iter)
{
drm_i915_private_t *dev_priv = dev->dev_private;
- struct drm_gem_object *obj;
- struct drm_i915_gem_object *obj_priv;
- struct drm_gem_object *best = NULL;
- struct drm_gem_object *first = NULL;
-
- /* Try to find the smallest clean object */
- list_for_each_entry(obj_priv, &dev_priv->mm.inactive_list, list) {
- struct drm_gem_object *obj = &obj_priv->base;
- if (obj->size >= min_size) {
- if ((!obj_priv->dirty ||
- i915_gem_object_is_purgeable(obj_priv)) &&
- (!best || obj->size < best->size)) {
- best = obj;
- if (best->size == min_size)
- break;
- }
- if (!first)
- first = obj;
- }
- }
+ struct drm_i915_gem_object *render_obj = NULL, *bsd_obj = NULL;
- obj = best ? best : first;
+ if (*render_iter != &dev_priv->render_ring.active_list)
+ render_obj = list_entry(*render_iter,
+ struct drm_i915_gem_object,
+ list);
- if (!obj) {
- *found = 0;
- return 0;
- }
+ if (HAS_BSD(dev)) {
+ if (*bsd_iter != &dev_priv->bsd_ring.active_list)
+ bsd_obj = list_entry(*bsd_iter,
+ struct drm_i915_gem_object,
+ list);
- *found = 1;
+ if (render_obj == NULL) {
+ *bsd_iter = (*bsd_iter)->next;
+ return bsd_obj;
+ }
-#if WATCH_LRU
- DRM_INFO("%s: evicting %p\n", __func__, obj);
-#endif
- obj_priv = to_intel_bo(obj);
- BUG_ON(obj_priv->pin_count != 0);
- BUG_ON(obj_priv->active);
+ if (bsd_obj == NULL) {
+ *render_iter = (*render_iter)->next;
+ return render_obj;
+ }
- /* Wait on the rendering and unbind the buffer. */
- return i915_gem_object_unbind(obj);
+ /* XXX can we handle seqno wrapping? */
+ if (render_obj->last_rendering_seqno < bsd_obj->last_rendering_seqno) {
+ *render_iter = (*render_iter)->next;
+ return render_obj;
+ } else {
+ *bsd_iter = (*bsd_iter)->next;
+ return bsd_obj;
+ }
+ } else {
+ *render_iter = (*render_iter)->next;
+ return render_obj;
+ }
}
-static void
-i915_gem_flush_ring(struct drm_device *dev,
- uint32_t invalidate_domains,
- uint32_t flush_domains,
- struct intel_ring_buffer *ring)
+static bool
+mark_free(struct drm_i915_gem_object *obj_priv,
+ struct list_head *unwind)
{
- if (flush_domains & I915_GEM_DOMAIN_CPU)
- drm_agp_chipset_flush(dev);
- ring->flush(dev, ring,
- invalidate_domains,
- flush_domains);
+ list_add(&obj_priv->evict_list, unwind);
+ return drm_mm_scan_add_block(obj_priv->gtt_space);
}
+#define i915_for_each_active_object(OBJ, R, B) \
+ *(R) = dev_priv->render_ring.active_list.next; \
+ *(B) = dev_priv->bsd_ring.active_list.next; \
+ while (((OBJ) = i915_gem_next_active_object(dev, (R), (B))) != NULL)
+
int
-i915_gem_evict_something(struct drm_device *dev,
- int min_size, unsigned alignment)
+i915_gem_evict_something(struct drm_device *dev, int min_size, unsigned alignment)
{
drm_i915_private_t *dev_priv = dev->dev_private;
- int ret, found;
-
- struct intel_ring_buffer *render_ring = &dev_priv->render_ring;
- struct intel_ring_buffer *bsd_ring = &dev_priv->bsd_ring;
- for (;;) {
- i915_gem_retire_requests(dev);
-
- /* If there's an inactive buffer available now, grab it
- * and be done.
- */
- ret = i915_gem_scan_inactive_list_and_evict(dev, min_size,
- alignment,
- &found);
- if (found)
- return ret;
+ struct list_head eviction_list, unwind_list;
+ struct drm_i915_gem_object *obj_priv, *tmp_obj_priv;
+ struct list_head *render_iter, *bsd_iter;
+ int ret = 0;
- /* If we didn't get anything, but the ring is still processing
- * things, wait for the next to finish and hopefully leave us
- * a buffer to evict.
- */
- if (!list_empty(&render_ring->request_list)) {
- struct drm_i915_gem_request *request;
+ i915_gem_retire_requests(dev);
- request = list_first_entry(&render_ring->request_list,
- struct drm_i915_gem_request,
- list);
+ /* Re-check for free space after retiring requests */
+ if (drm_mm_search_free(&dev_priv->mm.gtt_space,
+ min_size, alignment, 0))
+ return 0;
- ret = i915_do_wait_request(dev, request->seqno, true, request->ring);
- if (ret)
- return ret;
+ /*
+ * The goal is to evict objects and amalgamate space in LRU order.
+ * The oldest idle objects reside on the inactive list, which is in
+ * retirement order. The next objects to retire are those on the (per
+ * ring) active list that do not have an outstanding flush. Once the
+ * hardware reports completion (the seqno is updated after the
+ * batchbuffer has been finished) the clean buffer objects would
+ * be retired to the inactive list. Any dirty objects would be added
+ * to the tail of the flushing list. So after processing the clean
+ * active objects we need to emit a MI_FLUSH to retire the flushing
+ * list, hence the retirement order of the flushing list is in
+ * advance of the dirty objects on the active lists.
+ *
+ * The retirement sequence is thus:
+ * 1. Inactive objects (already retired)
+ * 2. Clean active objects
+ * 3. Flushing list
+ * 4. Dirty active objects.
+ *
+ * On each list, the oldest objects lie at the HEAD with the freshest
+ * object on the TAIL.
+ */
+
+ INIT_LIST_HEAD(&unwind_list);
+ drm_mm_init_scan(&dev_priv->mm.gtt_space, min_size, alignment);
+
+ /* First see if there is a large enough contiguous idle region... */
+ list_for_each_entry(obj_priv, &dev_priv->mm.inactive_list, list) {
+ if (mark_free(obj_priv, &unwind_list))
+ goto found;
+ }
+ /* Now merge in the soon-to-be-expired objects... */
+ i915_for_each_active_object(obj_priv, &render_iter, &bsd_iter) {
+ /* Does the object require an outstanding flush? */
+ if (obj_priv->base.write_domain || obj_priv->pin_count)
continue;
- }
- if (HAS_BSD(dev) && !list_empty(&bsd_ring->request_list)) {
- struct drm_i915_gem_request *request;
-
- request = list_first_entry(&bsd_ring->request_list,
- struct drm_i915_gem_request,
- list);
+ if (mark_free(obj_priv, &unwind_list))
+ goto found;
+ }
- ret = i915_do_wait_request(dev, request->seqno, true, request->ring);
- if (ret)
- return ret;
+ /* Finally add anything with a pending flush (in order of retirement) */
+ list_for_each_entry(obj_priv, &dev_priv->mm.flushing_list, list) {
+ if (obj_priv->pin_count)
+ continue;
+ if (mark_free(obj_priv, &unwind_list))
+ goto found;
+ }
+ i915_for_each_active_object(obj_priv, &render_iter, &bsd_iter) {
+ if (! obj_priv->base.write_domain || obj_priv->pin_count)
continue;
- }
- /* If we didn't have anything on the request list but there
- * are buffers awaiting a flush, emit one and try again.
- * When we wait on it, those buffers waiting for that flush
- * will get moved to inactive.
- */
- if (!list_empty(&dev_priv->mm.flushing_list)) {
- struct drm_gem_object *obj = NULL;
- struct drm_i915_gem_object *obj_priv;
-
- /* Find an object that we can immediately reuse */
- list_for_each_entry(obj_priv, &dev_priv->mm.flushing_list, list) {
- obj = &obj_priv->base;
- if (obj->size >= min_size)
- break;
-
- obj = NULL;
- }
-
- if (obj != NULL) {
- uint32_t seqno;
-
- i915_gem_flush_ring(dev,
- obj->write_domain,
- obj->write_domain,
- obj_priv->ring);
- seqno = i915_add_request(dev, NULL,
- obj->write_domain,
- obj_priv->ring);
- if (seqno == 0)
- return -ENOMEM;
- continue;
- }
+ if (mark_free(obj_priv, &unwind_list))
+ goto found;
+ }
+
+ /* Nothing found, clean up and bail out! */
+ list_for_each_entry(obj_priv, &unwind_list, evict_list) {
+ ret = drm_mm_scan_remove_block(obj_priv->gtt_space);
+ BUG_ON(ret);
+ }
+
+ return i915_gem_evict_everything(dev);
+
+found:
+ INIT_LIST_HEAD(&eviction_list);
+ list_for_each_entry_safe(obj_priv, tmp_obj_priv,
+ &unwind_list, evict_list) {
+ if (drm_mm_scan_remove_block(obj_priv->gtt_space)) {
+ /* drm_mm doesn't allow any other other operations while
+ * scanning, therefore store to be evicted objects on a
+ * temporary list. */
+ list_move(&obj_priv->evict_list, &eviction_list);
}
+ }
- /* If we didn't do any of the above, there's no single buffer
- * large enough to swap out for the new one, so just evict
- * everything and start again. (This should be rare.)
- */
- if (!list_empty(&dev_priv->mm.inactive_list))
- return i915_gem_evict_inactive(dev);
- else
- return i915_gem_evict_everything(dev);
+ /* Unbinding will emit any required flushes */
+ list_for_each_entry_safe(obj_priv, tmp_obj_priv,
+ &eviction_list, evict_list) {
+#if WATCH_LRU
+ DRM_INFO("%s: evicting %p\n", __func__, obj);
+#endif
+ ret = i915_gem_object_unbind(&obj_priv->base);
+ if (ret)
+ return ret;
}
+
+ /* The just created free hole should be on the top of the free stack
+ * maintained by drm_mm, so this BUG_ON actually executes in O(1).
+ * Furthermore all accessed data has just recently been used, so it
+ * should be really fast, too. */
+ BUG_ON(!drm_mm_search_free(&dev_priv->mm.gtt_space, min_size,
+ alignment, 0));
+
+ return 0;
}
int