Re: [PATCH 4/4] drm/i915: Use eb for more stuff

[Ben Widawsky <ben@bwidawsk.net>]

On Thu, Oct 13, 2011 at 01:00:02PM +0100, Chris Wilson wrote:
> On Thu, 13 Oct 2011 10:58:25 +0200, Daniel Vetter <daniel@ffwll.ch> wrote:
> > On Wed, Oct 12, 2011 at 03:56:22PM -0700, Ben Widawsky wrote:
> > > This refactor is useful for some future work I'll be doing on the
> > > execbuffer path. In addition to being a pretty easy prerequisite, it
> > > also helped me track down the bug uncovered in the first patch.
> > > 
> > > Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
> > > ---
> > >  drivers/gpu/drm/i915/i915_gem_execbuffer.c |  102 ++++++++++++++--------------
> > >  1 files changed, 51 insertions(+), 51 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> > > index 182a2b9..b3beaae 100644
> > > --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> > > +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> > > @@ -40,6 +40,16 @@ struct change_domains {
> > >  	uint32_t flips;
> > >  };
> > >  
> > > +struct eb_objects {
> > > +	struct drm_i915_gem_object *batch_obj;
> > > +	struct list_head objects;
> > > +	int buffer_count;
> > > +	int mode;
> > > +	int and;
> > 
> > While you whack this code, can you do an s/and/end, I think that's just a
> > typo ...
> 
> It was meant to be 'and' since it was the value of the mask I was anding
> with. I'm sorry I appear to have spent too much time inside the Xserver,
> end = and + 1.
> > 
> > > +	struct hlist_head buckets[0];
> > > +	/* DO NOT PUT ANYTHING HERE */
> > 
> > When you drop the array size, the compiler will enforce that for you (for
> > $compiler = gcc at least).
> 
> I wanted to say that surely the comment was obvious from the '[0]' ;-)
> 

Well not obvious to me. Though it hindsight it should have been obvious.
GCC 4.6.1 does not produce an error or warning if you do this.

> 
> > > -	mode = args->flags & I915_EXEC_CONSTANTS_MASK;
> > > -	ret = i915_gem_set_constant_offset(ring, mode);
> > > +	eb->mode = args->flags & I915_EXEC_CONSTANTS_MASK;
> > > +	ret = i915_gem_set_constant_offset(ring, eb->mode);
> > 
> > The eb->mode refactor here otoh looks a bit superflous. Is this needed for
> > a future patch of yours?
> 
> I'm waiting to see how this pans out as well... ;-)
> -Chris

It's needed for a future patch, I'm cool with call this superfluous for
now, and Keith can take it, or wait until it's needed. I can make it a
bit more uniform as Chris recommended in some other comment.

Ben