From 8325a09dd0b138484ccff66b2987f49fa3813ec8 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Tue, 24 Apr 2012 15:52:35 +0100 Subject: [PATCH] drm/i915: Bump the inactive LRU on set-to-GTT-domain Currently, we only bump the inactive LRU of an object when we bind into the GTT for a page-fault. As the object may be used many times before its mapping is zapped, we do not mark it as active as frequently as we should. Userspace should be calling set-to-GTT-domain before each pointer deference (for synchronous access) and so is a good place to mark the buffer as active. Marking the buffer as recently used places it at the end of the inactive eviction queue, though still before anything with outstanding rendering. This reduces the likelihood of evicting a buffer that is going to be used again by the CPU in the near future. This way we can hopefully avoid to kick out upload buffers right before we use them on the gpu. Note that we need to check that the object is not active or pinned, for otherwise we create havoc on the active/pinned lists, which also use obj->mm_list. The active lists are sorted by and evicted in last GPU rendering order, access by the CPU to a still active buffer therefore does not affect its eviction ordering. Pinned objects are currently excluded from eviction, therefore the only list that we need to bump for GTT access by the CPU is the inactive list. Signed-off-by: Chris Wilson [danvet: Added further explanations to the commit message as discussed on irc.] Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_gem.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index cfbcf7e..ad2a692 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -132,7 +132,7 @@ int i915_mutex_lock_interruptible(struct drm_device *dev) static inline bool i915_gem_object_is_inactive(struct drm_i915_gem_object *obj) { - return obj->gtt_space && !obj->active && obj->pin_count == 0; + return !obj->active && obj->pin_count == 0; } int @@ -2737,6 +2737,7 @@ i915_gem_object_flush_cpu_write_domain(struct drm_i915_gem_object *obj) int i915_gem_object_set_to_gtt_domain(struct drm_i915_gem_object *obj, bool write) { + drm_i915_private_t *dev_priv = obj->base.dev->dev_private; uint32_t old_write_domain, old_read_domains; int ret; @@ -2777,6 +2778,10 @@ i915_gem_object_set_to_gtt_domain(struct drm_i915_gem_object *obj, bool write) old_read_domains, old_write_domain); + /* And bump the LRU for this access */ + if (i915_gem_object_is_inactive(obj)) + list_move_tail(&obj->mm_list, &dev_priv->mm.inactive_list); + return 0; } -- 2.7.4