[Intel-gfx] [PATCH 23/41] drm/i915: Acquire the backing storage outside of struct_mutex in set-domain
Chris Wilson
chris at chris-wilson.co.uk
Thu Oct 20 15:04:05 UTC 2016
As we can locklessly (well struct_mutex-lessly) acquire the backing
storage, do so in set-domain-ioctl to reduce the contention on the
struct_mutex.
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
---
drivers/gpu/drm/i915/i915_gem.c | 99 +++++++++++++++++++++++++----------------
1 file changed, 61 insertions(+), 38 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index ba311a104564..697a83823920 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1451,6 +1451,30 @@ write_origin(struct drm_i915_gem_object *obj, unsigned domain)
obj->frontbuffer_ggtt_origin : ORIGIN_CPU);
}
+static void i915_gem_object_bump_inactive_ggtt(struct drm_i915_gem_object *obj)
+{
+ struct drm_i915_private *i915;
+ struct list_head *list;
+ struct i915_vma *vma;
+
+ list_for_each_entry(vma, &obj->vma_list, obj_link) {
+ if (!i915_vma_is_ggtt(vma))
+ continue;
+
+ if (i915_vma_is_active(vma))
+ continue;
+
+ if (!drm_mm_node_allocated(&vma->node))
+ continue;
+
+ list_move_tail(&vma->vm_link, &vma->vm->inactive_list);
+ }
+
+ i915 = to_i915(obj->base.dev);
+ list = obj->bind_count ? &i915->mm.bound_list : &i915->mm.unbound_list;
+ list_move_tail(&obj->global_list, list);
+}
+
/**
* Called when user space prepares to use an object with the CPU, either
* through the mmap ioctl's mapping or a GTT mapping.
@@ -1466,7 +1490,7 @@ i915_gem_set_domain_ioctl(struct drm_device *dev, void *data,
struct drm_i915_gem_object *obj;
uint32_t read_domains = args->read_domains;
uint32_t write_domain = args->write_domain;
- int ret;
+ int err;
/* Only handle setting domains to types used by the CPU. */
if ((write_domain | read_domains) & I915_GEM_GPU_DOMAINS)
@@ -1486,33 +1510,48 @@ i915_gem_set_domain_ioctl(struct drm_device *dev, void *data,
* We will repeat the flush holding the lock in the normal manner
* to catch cases where we are gazumped.
*/
- ret = i915_gem_object_wait(obj,
+ err = i915_gem_object_wait(obj,
I915_WAIT_INTERRUPTIBLE |
(write_domain ? I915_WAIT_ALL : 0),
MAX_SCHEDULE_TIMEOUT,
to_rps_client(file));
- if (ret)
- goto err;
+ if (err)
+ goto out_unlocked;
- ret = i915_mutex_lock_interruptible(dev);
- if (ret)
- goto err;
+ /* Flush and acquire obj->pages so that we are coherent through
+ * direct access in memory with previous cached writes through
+ * shmemfs and that our cache domain tracking remains valid.
+ * For example, if the obj->filp was moved to swap without us
+ * being notified and releasing the pages, we would mistakenly
+ * continue to assume that the obj remained out of the CPU cached
+ * domain.
+ */
+ err = i915_gem_object_pin_pages(obj);
+ if (err)
+ goto out_unlocked;
+
+ err = i915_mutex_lock_interruptible(dev);
+ if (err)
+ goto out_pages;
if (read_domains & I915_GEM_DOMAIN_GTT)
- ret = i915_gem_object_set_to_gtt_domain(obj, write_domain != 0);
+ err = i915_gem_object_set_to_gtt_domain(obj, write_domain != 0);
else
- ret = i915_gem_object_set_to_cpu_domain(obj, write_domain != 0);
+ err = i915_gem_object_set_to_cpu_domain(obj, write_domain != 0);
- if (write_domain != 0)
- intel_fb_obj_invalidate(obj, write_origin(obj, write_domain));
+ /* And bump the LRU for this access */
+ i915_gem_object_bump_inactive_ggtt(obj);
- i915_gem_object_put(obj);
mutex_unlock(&dev->struct_mutex);
- return ret;
-err:
+ if (write_domain != 0)
+ intel_fb_obj_invalidate(obj, write_origin(obj, write_domain));
+
+out_pages:
+ i915_gem_object_unpin_pages(obj);
+out_unlocked:
i915_gem_object_put_unlocked(obj);
- return ret;
+ return err;
}
/**
@@ -1733,6 +1772,10 @@ int i915_gem_fault(struct vm_area_struct *area, struct vm_fault *vmf)
if (ret)
goto err;
+ ret = i915_gem_object_pin_pages(obj);
+ if (ret)
+ goto err;
+
intel_runtime_pm_get(dev_priv);
ret = i915_mutex_lock_interruptible(dev);
@@ -1815,6 +1858,7 @@ int i915_gem_fault(struct vm_area_struct *area, struct vm_fault *vmf)
mutex_unlock(&dev->struct_mutex);
err_rpm:
intel_runtime_pm_put(dev_priv);
+ i915_gem_object_unpin_pages(obj);
err:
switch (ret) {
case -EIO:
@@ -3272,24 +3316,6 @@ i915_gem_object_flush_cpu_write_domain(struct drm_i915_gem_object *obj)
I915_GEM_DOMAIN_CPU);
}
-static void i915_gem_object_bump_inactive_ggtt(struct drm_i915_gem_object *obj)
-{
- struct i915_vma *vma;
-
- list_for_each_entry(vma, &obj->vma_list, obj_link) {
- if (!i915_vma_is_ggtt(vma))
- continue;
-
- if (i915_vma_is_active(vma))
- continue;
-
- if (!drm_mm_node_allocated(&vma->node))
- continue;
-
- list_move_tail(&vma->vm_link, &vma->vm->inactive_list);
- }
-}
-
/**
* Moves a single object to the GTT read, and possibly write domain.
* @obj: object to act on
@@ -3345,7 +3371,7 @@ i915_gem_object_set_to_gtt_domain(struct drm_i915_gem_object *obj, bool write)
/* It should now be out of any other write domains, and we can update
* the domain values for our changes.
*/
- BUG_ON((obj->base.write_domain & ~I915_GEM_DOMAIN_GTT) != 0);
+ GEM_BUG_ON((obj->base.write_domain & ~I915_GEM_DOMAIN_GTT) != 0);
obj->base.read_domains |= I915_GEM_DOMAIN_GTT;
if (write) {
obj->base.read_domains = I915_GEM_DOMAIN_GTT;
@@ -3357,10 +3383,7 @@ 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 */
- i915_gem_object_bump_inactive_ggtt(obj);
i915_gem_object_unpin_pages(obj);
-
return 0;
}
@@ -3719,7 +3742,7 @@ i915_gem_object_set_to_cpu_domain(struct drm_i915_gem_object *obj, bool write)
/* It should now be out of any other write domains, and we can update
* the domain values for our changes.
*/
- BUG_ON((obj->base.write_domain & ~I915_GEM_DOMAIN_CPU) != 0);
+ GEM_BUG_ON((obj->base.write_domain & ~I915_GEM_DOMAIN_CPU) != 0);
/* If we're writing through the CPU, then the GPU read domains will
* need to be invalidated at next use.
--
2.9.3
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