Re: [PATCH] drm/mm: Adjust start/end for coloring first

From: Daniel Vetter <daniel@ffwll.ch>
To: Chris Wilson <chris@chris-wilson.co.uk>,
	Daniel Vetter <daniel@ffwll.ch>,
	dri-devel@lists.freedesktop.org
Subject: Re: [PATCH] drm/mm: Adjust start/end for coloring first
Date: Mon, 19 May 2014 12:22:27 +0200	[thread overview]
Message-ID: <20140519102227.GG8790@phenom.ffwll.local> (raw)
In-Reply-To: <20140519082123.GC11754@nuc-i3427.alporthouse.com>

On Mon, May 19, 2014 at 09:21:23AM +0100, Chris Wilson wrote:
> On Mon, May 19, 2014 at 10:14:27AM +0200, Daniel Vetter wrote:
> > On Mon, May 19, 2014 at 07:52:37AM +0100, Chris Wilson wrote:
> > > The current user of the coloring will adjust the end points of the node
> > > to leave a hole between disjoint memory types. This adjustment must be
> > > performed first or else the derived size will conflict with the
> > > adjustment and trigger the BUG_ON sanity checks that the node is within
> > > bounds.
> > > 
> > > Fixes regression from
> > > commit 62347f9e0f81d50e9b0923ec8a192f60ab7a1801
> > > Author: Lauri Kasanen <cand@gmx.com>
> > > Date:   Wed Apr 2 20:03:57 2014 +0300
> > > 
> > >     drm: Add support for two-ended allocation, v3
> > > 
> > > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> > 
> > Do we have a bugzilla for this, or why did igt not scream about this
> > failure?
> 
> How would igt scream? Look at the patch and think of how many possible
> ways the current kernel would explode. Then think about how they are
> exposed to userspace.

Yeah, reading the patch helps ;-) So this only collides with the top-down
vs. bottum-up separation patch for cache levels you've posted somewhere.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch