[Intel-gfx] [PATCH v4 1/7] drm/i915: Implement a framework for batch buffer pools

[Chris Wilson]

On Wed, Nov 12, 2014 at 05:33:08PM +0100, Daniel Vetter wrote:
> On Wed, Nov 12, 2014 at 10:46 AM, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> > On Wed, Nov 12, 2014 at 09:44:34AM +0100, Daniel Vetter wrote:
> >> On Fri, Nov 07, 2014 at 02:22:01PM -0800, bradley.d.volkin at intel.com wrote:
> >> > +           if (obj && obj->madv == __I915_MADV_PURGED) {
> >> > +                   was_purged = true;
> >> > +                   list_del(&obj->batch_pool_list);
> >> > +                   drm_gem_object_unreference(&obj->base);
> >> > +                   obj = NULL;
> >> > +           }
> >>
> >> Minor issue: We should move the purged check into the loop so that purge
> >> buffer structs get released even when they're too small/big. Otherwise
> >> we'll have a good chance to hang onto gobloads of structs forever.
> >
> > I mentioned that we should do the purge of structs in our oom-notifier
> > as well to be safe.
> 
> Given that we don't purge the sturcts for userspace purged objects (we
> could just clear everything but the idr slot and mark it specially) I
> don't think we need this here. At least not until we have this for
> userspace bos since there's lots more of those I think.

Well discarding userspace purged objects requires a special zombie
handle, but these pure in-kernel structs we have complete control over
and so are much simpler to clean up.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre