[Intel-gfx] [PATCH] drm/i915: Update write_domains on active list after flush.
Daniel Vetter
daniel.vetter at ffwll.ch
Sun Feb 7 16:20:18 CET 2010
Before changing the status of a buffer with a pending write we will await
upon a new flush for that buffer. So we can take advantage of any flushes
posted whilst the buffer is active and pending processing by the GPU, by
clearing its write_domain and updating its last_rendering_seqno -- thus
saving a potential flush in deep queues and improves flushing behaviour
upon eviction for both GTT space and fences.
In order to reduce the time spent searching the active list for matching
write_domains, we move those to a separate list whose elements are
the buffers belong to the active/flushing list with pending writes.
Orignal patch by Chris Wilson <chris at chris-wilson.co.uk>, forward-ported
by me.
In addition to better performance, this also fixes a real bug. Before
this changes, i915_gem_evict_everything didn't work as advertised. When
the gpu was actually busy and processing request, the flush and subsequent
wait would not move active and dirty buffers to the inactive list, but
just to the flushing list. Which triggered the BUG_ON at the end of this
function. With the more tight dirty buffer tracking, all currently busy and
dirty buffers get moved to the inactive list by one i915_gem_flush operation.
I've left the BUG_ON I've used to prove this in there.
References:
Bug 25911 - 2.10.0 causes kernel oops and system hangs
http://bugs.freedesktop.org/show_bug.cgi?id=25911
Bug 26101 - [i915] xf86-video-intel 2.10.0 (and git) triggers kernel oops
within seconds after login
http://bugs.freedesktop.org/show_bug.cgi?id=26101
Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
Same patch rebased to apply to .32-stable (and linus mainlin, too).
Compile-tested only.
drivers/gpu/drm/i915/i915_drv.h | 11 +++++++++++
drivers/gpu/drm/i915/i915_gem.c | 23 +++++++++++++++++++----
2 files changed, 30 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 791fded..2c031cf 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -467,6 +467,15 @@ typedef struct drm_i915_private {
struct list_head flushing_list;
/**
+ * List of objects currently pending a GPU write flush.
+ *
+ * All elements on this list will belong to either the
+ * active_list or flushing_list, last_rendering_seqno can
+ * be used to differentiate between the two elements.
+ */
+ struct list_head gpu_write_list;
+
+ /**
* LRU list of objects which are not in the ringbuffer and
* are ready to unbind, but are still in the GTT.
*
@@ -558,6 +567,8 @@ struct drm_i915_gem_object {
/** This object's place on the active/flushing/inactive lists */
struct list_head list;
+ /** This object's place on GPU write list */
+ struct list_head gpu_write_list;
/** This object's place on the fenced object LRU */
struct list_head fence_list;
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index df2c625..b2e0742 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1568,6 +1568,8 @@ i915_gem_object_move_to_inactive(struct drm_gem_object *obj)
else
list_move_tail(&obj_priv->list, &dev_priv->mm.inactive_list);
+ BUG_ON(!list_empty(&obj_priv->gpu_write_list));
+
obj_priv->last_rendering_seqno = 0;
if (obj_priv->active) {
obj_priv->active = 0;
@@ -1638,7 +1640,8 @@ i915_add_request(struct drm_device *dev, struct drm_file *file_priv,
struct drm_i915_gem_object *obj_priv, *next;
list_for_each_entry_safe(obj_priv, next,
- &dev_priv->mm.flushing_list, list) {
+ &dev_priv->mm.gpu_write_list,
+ gpu_write_list) {
struct drm_gem_object *obj = obj_priv->obj;
if ((obj->write_domain & flush_domains) ==
@@ -1646,6 +1649,7 @@ i915_add_request(struct drm_device *dev, struct drm_file *file_priv,
uint32_t old_write_domain = obj->write_domain;
obj->write_domain = 0;
+ list_del_init(&obj_priv->gpu_write_list);
i915_gem_object_move_to_active(obj, seqno);
trace_i915_gem_object_change_domain(obj,
@@ -2089,8 +2093,8 @@ static int
i915_gem_evict_everything(struct drm_device *dev)
{
drm_i915_private_t *dev_priv = dev->dev_private;
- uint32_t seqno;
int ret;
+ uint32_t seqno;
bool lists_empty;
spin_lock(&dev_priv->mm.active_list_lock);
@@ -2112,6 +2116,8 @@ i915_gem_evict_everything(struct drm_device *dev)
if (ret)
return ret;
+ BUG_ON(!list_empty(&dev_priv->mm.flushing_list));
+
ret = i915_gem_evict_from_inactive_list(dev);
if (ret)
return ret;
@@ -2710,7 +2716,7 @@ i915_gem_object_flush_gpu_write_domain(struct drm_gem_object *obj)
old_write_domain = obj->write_domain;
i915_gem_flush(dev, 0, obj->write_domain);
seqno = i915_add_request(dev, NULL, obj->write_domain);
- obj->write_domain = 0;
+ BUG_ON(obj->write_domain);
i915_gem_object_move_to_active(obj, seqno);
trace_i915_gem_object_change_domain(obj,
@@ -3730,16 +3736,23 @@ i915_gem_execbuffer(struct drm_device *dev, void *data,
i915_gem_flush(dev,
dev->invalidate_domains,
dev->flush_domains);
- if (dev->flush_domains)
+ if (dev->flush_domains & I915_GEM_GPU_DOMAINS)
(void)i915_add_request(dev, file_priv,
dev->flush_domains);
}
for (i = 0; i < args->buffer_count; i++) {
struct drm_gem_object *obj = object_list[i];
+ struct drm_i915_gem_object *obj_priv = obj->driver_private;
uint32_t old_write_domain = obj->write_domain;
obj->write_domain = obj->pending_write_domain;
+ if (obj->write_domain)
+ list_move_tail(&obj_priv->gpu_write_list,
+ &dev_priv->mm.gpu_write_list);
+ else
+ list_del_init(&obj_priv->gpu_write_list);
+
trace_i915_gem_object_change_domain(obj,
obj->read_domains,
old_write_domain);
@@ -4132,6 +4145,7 @@ int i915_gem_init_object(struct drm_gem_object *obj)
obj_priv->obj = obj;
obj_priv->fence_reg = I915_FENCE_REG_NONE;
INIT_LIST_HEAD(&obj_priv->list);
+ INIT_LIST_HEAD(&obj_priv->gpu_write_list);
INIT_LIST_HEAD(&obj_priv->fence_list);
obj_priv->madv = I915_MADV_WILLNEED;
@@ -4583,6 +4597,7 @@ i915_gem_load(struct drm_device *dev)
spin_lock_init(&dev_priv->mm.active_list_lock);
INIT_LIST_HEAD(&dev_priv->mm.active_list);
INIT_LIST_HEAD(&dev_priv->mm.flushing_list);
+ INIT_LIST_HEAD(&dev_priv->mm.gpu_write_list);
INIT_LIST_HEAD(&dev_priv->mm.inactive_list);
INIT_LIST_HEAD(&dev_priv->mm.request_list);
INIT_LIST_HEAD(&dev_priv->mm.fence_list);
--
1.6.6.1
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