Re: [PATCH] drm/i915: Fix list corruption in vma_unbind

[Ben Widawsky <ben@bwidawsk.net>]

On Thu, Aug 29, 2013 at 10:19:24PM +0100, Chris Wilson wrote:
> On Thu, Aug 29, 2013 at 11:06:24PM +0200, Daniel Vetter wrote:
> > On Thu, Aug 29, 2013 at 07:57:38PM +0100, Chris Wilson wrote:
> > > On Thu, Aug 29, 2013 at 07:50:31PM +0200, Daniel Vetter wrote:
> > > > The saga around the breadcrumb vmas used by execbuf continues ...
> > > > 
> > > > This time around we've managed to unconditionally move the object to
> > > > the unbound list on the last vma unbind even though it might never
> > > > have been on either the bound or unbound list. Hilarity ensued.
> > > > 
> > > > Chris Wilson tracked this one down but compared to his patches I've
> > > > simply opted to completely separate the unbound case for not-yet bound
> > > > vmas. Otherwise we imo end up with semantically hard to parse checks
> > > > around the list_move_tail(global_list, ...).
> > > > 
> > > > This is exercised by the new swapping variants of
> > > > igt/tests/gem_evict_everything.
> > > > 
> > > > Cc: Chris Wilson <chris@chris-wilson.co.uk>
> > > > Cc: Ben Widawsky <ben@bwidawsk.net>
> > > > Bugzilla: https://bugs.freedesktop.org/attachment.cgi?id=84818
> > > > Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> > > 
> > > Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
> > 
> > Merged, but I've dropped the paragraph about the igt tests again - I just
> > can't hit the bug any more :( Also I've fixed the bugzilla link, it
> > pointed at an attachment instead of the bug.
> 
> It fixed the tests for me, just got a whole new trace when using GL.
> -Chris
> 
> -- 
> Chris Wilson, Intel Open Source Technology Centre

I'm not really sure why the assertion I added blew up :/
Tested-by: Ben Widawsky <ben@bwidawsk.net>

-- 
Ben Widawsky, Intel Open Source Technology Center