[Intel-gfx] [PATCH] drm/i915: Add a debug interface to forcibly evict and shrink our object caches

[Daniel Vetter]

On Tue, Jan 15, 2013 at 12:39:35PM +0000, Chris Wilson wrote:
> 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 at chris-wilson.co.uk>

Queued for -next, thanks for the patch.
-Daniel
> ---
>  drivers/gpu/drm/i915/i915_debugfs.c |  102 +++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/i915/i915_drv.h     |    1 +
>  drivers/gpu/drm/i915/i915_gem.c     |    2 +-
>  3 files changed, 104 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index 882a735..3041bab 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -1776,6 +1776,100 @@ static const struct file_operations i915_ring_stop_fops = {
>  	.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);
> +
> +	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 +2267,12 @@ int i915_debugfs_init(struct drm_minor *minor)
>  		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 +2303,8 @@ void i915_debugfs_cleanup(struct drm_minor *minor)
>  				 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 0a42df1..233216f 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1430,6 +1430,7 @@ int __must_check i915_gem_object_pin(struct drm_i915_gem_object *obj,
>  				     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 e279d91..41245e9 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -1656,7 +1656,7 @@ i915_gem_object_put_pages_gtt(struct drm_i915_gem_object *obj)
>  	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;
> -- 
> 1.7.10.4
> 
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> Intel-gfx at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch