drm/i915: Add a debug interface to forcibly evict and shrink our object caches
As a means to investigate some bad system behaviour related to the
purging of the active, inactive and unbound lists, it is useful to be
able to manually control when those lists should be cleared.
v2: use _safe list iterators as we kick objects from the list as we
walk.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
[danvet: Add a small comment explaining why we don't need to check and
wait for gpu resets, acked by Chris on irc.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index f7d88e9..f94418bd 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1776,6 +1776,102 @@
.llseek = default_llseek,
};
+#define DROP_UNBOUND 0x1
+#define DROP_BOUND 0x2
+#define DROP_RETIRE 0x4
+#define DROP_ACTIVE 0x8
+#define DROP_ALL (DROP_UNBOUND | \
+ DROP_BOUND | \
+ DROP_RETIRE | \
+ DROP_ACTIVE)
+static ssize_t
+i915_drop_caches_read(struct file *filp,
+ char __user *ubuf,
+ size_t max,
+ loff_t *ppos)
+{
+ char buf[20];
+ int len;
+
+ len = snprintf(buf, sizeof(buf), "0x%08x\n", DROP_ALL);
+ if (len > sizeof(buf))
+ len = sizeof(buf);
+
+ return simple_read_from_buffer(ubuf, max, ppos, buf, len);
+}
+
+static ssize_t
+i915_drop_caches_write(struct file *filp,
+ const char __user *ubuf,
+ size_t cnt,
+ loff_t *ppos)
+{
+ struct drm_device *dev = filp->private_data;
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ struct drm_i915_gem_object *obj, *next;
+ char buf[20];
+ int val = 0, ret;
+
+ if (cnt > 0) {
+ if (cnt > sizeof(buf) - 1)
+ return -EINVAL;
+
+ if (copy_from_user(buf, ubuf, cnt))
+ return -EFAULT;
+ buf[cnt] = 0;
+
+ val = simple_strtoul(buf, NULL, 0);
+ }
+
+ DRM_DEBUG_DRIVER("Dropping caches: 0x%08x\n", val);
+
+ /* No need to check and wait for gpu resets, only libdrm auto-restarts
+ * on ioctls on -EAGAIN. */
+ ret = mutex_lock_interruptible(&dev->struct_mutex);
+ if (ret)
+ return ret;
+
+ if (val & DROP_ACTIVE) {
+ ret = i915_gpu_idle(dev);
+ if (ret)
+ goto unlock;
+ }
+
+ if (val & (DROP_RETIRE | DROP_ACTIVE))
+ i915_gem_retire_requests(dev);
+
+ if (val & DROP_BOUND) {
+ list_for_each_entry_safe(obj, next, &dev_priv->mm.inactive_list, mm_list)
+ if (obj->pin_count == 0) {
+ ret = i915_gem_object_unbind(obj);
+ if (ret)
+ goto unlock;
+ }
+ }
+
+ if (val & DROP_UNBOUND) {
+ list_for_each_entry_safe(obj, next, &dev_priv->mm.unbound_list, gtt_list)
+ if (obj->pages_pin_count == 0) {
+ ret = i915_gem_object_put_pages(obj);
+ if (ret)
+ goto unlock;
+ }
+ }
+
+unlock:
+ mutex_unlock(&dev->struct_mutex);
+
+ return ret ?: cnt;
+}
+
+static const struct file_operations i915_drop_caches_fops = {
+ .owner = THIS_MODULE,
+ .open = simple_open,
+ .read = i915_drop_caches_read,
+ .write = i915_drop_caches_write,
+ .llseek = default_llseek,
+};
+
static ssize_t
i915_max_freq_read(struct file *filp,
char __user *ubuf,
@@ -2173,6 +2269,12 @@
return ret;
ret = i915_debugfs_create(minor->debugfs_root, minor,
+ "i915_gem_drop_caches",
+ &i915_drop_caches_fops);
+ if (ret)
+ return ret;
+
+ ret = i915_debugfs_create(minor->debugfs_root, minor,
"i915_error_state",
&i915_error_state_fops);
if (ret)
@@ -2203,6 +2305,8 @@
1, minor);
drm_debugfs_remove_files((struct drm_info_list *) &i915_cache_sharing_fops,
1, minor);
+ drm_debugfs_remove_files((struct drm_info_list *) &i915_drop_caches_fops,
+ 1, minor);
drm_debugfs_remove_files((struct drm_info_list *) &i915_ring_stop_fops,
1, minor);
drm_debugfs_remove_files((struct drm_info_list *) &i915_error_state_fops,
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 35ecabc..8f5b281 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1445,6 +1445,7 @@
bool nonblocking);
void i915_gem_object_unpin(struct drm_i915_gem_object *obj);
int __must_check i915_gem_object_unbind(struct drm_i915_gem_object *obj);
+int i915_gem_object_put_pages(struct drm_i915_gem_object *obj);
void i915_gem_release_mmap(struct drm_i915_gem_object *obj);
void i915_gem_lastclose(struct drm_device *dev);
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 313bdbab..9d33fb3 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1662,7 +1662,7 @@
kfree(obj->pages);
}
-static int
+int
i915_gem_object_put_pages(struct drm_i915_gem_object *obj)
{
const struct drm_i915_gem_object_ops *ops = obj->ops;