[Intel-gfx] [PATCH] drm/i915: Update write_domains on active list after flush.

[Adam Lantos]

On Sun, Feb 7, 2010 at 4:20 PM, Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
> Before changing the status of a buffer with a pending write we will await
> upon a new flush for that buffer. So we can take advantage of any flushes
> posted whilst the buffer is active and pending processing by the GPU, by
> clearing its write_domain and updating its last_rendering_seqno -- thus
> saving a potential flush in deep queues and improves flushing behaviour
> upon eviction for both GTT space and fences.
>
> In order to reduce the time spent searching the active list for matching
> write_domains, we move those to a separate list whose elements are
> the buffers belong to the active/flushing list with pending writes.
>
> Orignal patch by Chris Wilson <chris at chris-wilson.co.uk>, forward-ported
> by me.
>
> In addition to better performance, this also fixes a real bug. Before
> this changes, i915_gem_evict_everything didn't work as advertised. When
> the gpu was actually busy and processing request, the flush and subsequent
> wait would not move active and dirty buffers to the inactive list, but
> just to the flushing list. Which triggered the BUG_ON at the end of this
> function. With the more tight dirty buffer tracking, all currently busy and
> dirty buffers get moved to the inactive list by one i915_gem_flush operation.
>
> I've left the BUG_ON I've used to prove this in there.
>
> References:
>  Bug 25911 - 2.10.0 causes kernel oops and system hangs
>  http://bugs.freedesktop.org/show_bug.cgi?id=25911
>
>  Bug 26101 - [i915] xf86-video-intel 2.10.0 (and git) triggers kernel oops
>              within seconds after login
>  http://bugs.freedesktop.org/show_bug.cgi?id=26101
>
> Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> ---
>
> Same patch rebased to apply to .32-stable (and linus mainlin, too).
> Compile-tested only.

This patch seems to fix the BUG_ON in my case. However, I still have
lots of these:

[drm:i915_gem_object_pin_and_relocate] *ERROR* Failure to install fence: -28
[drm:i915_gem_object_pin_and_relocate] *ERROR* Failure to install fence: -28
[drm:i915_gem_do_execbuffer] *ERROR* Failed to pin buffer 5 of 7,
total 8519680 bytes: -28
[drm:i915_gem_do_execbuffer] *ERROR* 369 objects [7 pinned], 91172864
object bytes [11747328 pinned], 11780096/260308992 gtt bytes

and also visual corruption in the 'present windows' plugin (which was
working fine w/ 2.6.32.y)


thanks,
 Adam