Re: Regression since 53984635a659e360f206a81ada4ae813152d72f1 (drm/i915: use the complete gtt)

[Peter Clifton <pcjc2@cam.ac.uk>]

On Tue, 2010-11-09 at 18:22 +0000, Peter Clifton wrote:
> commit 53984635a659e360f206a81ada4ae813152d72f1
> Author: Daniel Vetter <daniel.vetter@ffwll.ch>
> Date:   Wed Sep 22 23:44:24 2010 +0200
> 
>     drm/i915: use the complete gtt
>     
>     At least the part that's currently enabled by the BIOS.
>     
>     Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
>     Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> 
> 
> Since the above commit, my GL app will crash after a period of sustained
> graphics activity. It appears to use quite a lot of small BOs for
> uploading changed VBO data with glBufferSubData, and I don't think these
> are being purged until the GTT is full.

I can also work around the crash by ensuring nothing gets into unmapable
areas:

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 7c91bf2..d014cd6 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3538,6 +3538,7 @@ i915_gem_execbuffer_pin(struct drm_device *dev,
                        /* g33/pnv can't fence buffers in the unmappable part */
                        bool need_mappable =
                                entry->relocation_count ? true : need_fence;
+                       need_mappable = true;
 
                        /* Check fence reg constraints and rebind if necessary */
                        if (need_mappable && !obj->map_and_fenceable) {

-- 
Peter Clifton

Electrical Engineering Division,
Engineering Department,
University of Cambridge,
9, JJ Thomson Avenue,
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