[PATCH] drm/i915: Pin the object whilst faulting it in

[PATCH] drm/i915: Pin the object whilst faulting it in

[Chris Wilson]

In order to prevent reaping of the object whilst setting it up to
handle the pagefault, we need to mark it as pinned. This has the nice
side-effect of eliminating some special cases from the pagefault handler
as well!

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_gem.c |   19 +++++++------------
 1 file changed, 7 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index b4eb3ee..2e84ae13 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1452,23 +1452,16 @@ int i915_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	trace_i915_gem_object_fault(obj, page_offset, true, write);
 
 	/* Now bind it into the GTT if needed */
-	if (!obj->map_and_fenceable) {
-		ret = i915_gem_object_unbind(obj);
-		if (ret)
-			goto unlock;
-	}
-	if (!obj->gtt_space) {
-		ret = i915_gem_object_bind_to_gtt(obj, 0, true, false);
-		if (ret)
-			goto unlock;
-	}
+	ret = i915_gem_object_pin(obj, 0, true, false);
+	if (ret)
+		goto unlock;
 
 	if (!obj->has_global_gtt_mapping)
 		i915_gem_gtt_bind_object(obj, obj->cache_level);
 
 	ret = i915_gem_object_get_fence(obj);
 	if (ret)
-		goto unlock;
+		goto unpin;
 
 	if (i915_gem_object_is_inactive(obj))
 		list_move_tail(&obj->mm_list, &dev_priv->mm.inactive_list);
@@ -1481,7 +1474,7 @@ int i915_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	/* Finally, remap it using the new GTT offset */
 	ret = vm_insert_pfn(vma, (unsigned long)vmf->virtual_address, pfn);
 	if (ret)
-		goto unlock;
+		goto unpin;
 
 	prefault = 16;
 	if (page_offset + prefault >= obj->base.size >> PAGE_SHIFT)
@@ -1492,6 +1485,8 @@ int i915_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 		if (vm_insert_pfn(vma, page_offset, pfn))
 			break;
 	}
+unpin:
+	i915_gem_object_unpin(obj);
 unlock:
 	mutex_unlock(&dev->struct_mutex);
 out:
-- 
1.7.10.4

Re: [PATCH] drm/i915: Pin the object whilst faulting it in

[Daniel Vetter]

On Tue, Nov 20, 2012 at 10:03:14AM +0000, Chris Wilson wrote:
> In order to prevent reaping of the object whilst setting it up to
> handle the pagefault, we need to mark it as pinned. This has the nice
> side-effect of eliminating some special cases from the pagefault handler
> as well!
> 
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

Can you rebase this on top of dinq pls? I don't have a 16 page prefaulter
here ... ;-)
-Daniel

> ---
>  drivers/gpu/drm/i915/i915_gem.c |   19 +++++++------------
>  1 file changed, 7 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index b4eb3ee..2e84ae13 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -1452,23 +1452,16 @@ int i915_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
>  	trace_i915_gem_object_fault(obj, page_offset, true, write);
>  
>  	/* Now bind it into the GTT if needed */
> -	if (!obj->map_and_fenceable) {
> -		ret = i915_gem_object_unbind(obj);
> -		if (ret)
> -			goto unlock;
> -	}
> -	if (!obj->gtt_space) {
> -		ret = i915_gem_object_bind_to_gtt(obj, 0, true, false);
> -		if (ret)
> -			goto unlock;
> -	}
> +	ret = i915_gem_object_pin(obj, 0, true, false);
> +	if (ret)
> +		goto unlock;
>  
>  	if (!obj->has_global_gtt_mapping)
>  		i915_gem_gtt_bind_object(obj, obj->cache_level);
>  
>  	ret = i915_gem_object_get_fence(obj);
>  	if (ret)
> -		goto unlock;
> +		goto unpin;
>  
>  	if (i915_gem_object_is_inactive(obj))
>  		list_move_tail(&obj->mm_list, &dev_priv->mm.inactive_list);
> @@ -1481,7 +1474,7 @@ int i915_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
>  	/* Finally, remap it using the new GTT offset */
>  	ret = vm_insert_pfn(vma, (unsigned long)vmf->virtual_address, pfn);
>  	if (ret)
> -		goto unlock;
> +		goto unpin;
>  
>  	prefault = 16;
>  	if (page_offset + prefault >= obj->base.size >> PAGE_SHIFT)
> @@ -1492,6 +1485,8 @@ int i915_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
>  		if (vm_insert_pfn(vma, page_offset, pfn))
>  			break;
>  	}
> +unpin:
> +	i915_gem_object_unpin(obj);
>  unlock:
>  	mutex_unlock(&dev->struct_mutex);
>  out:
> -- 
> 1.7.10.4
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@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