[Intel-gfx] [PATCH 088/190] drm/i915: Move execlists interrupt based submission to a bottom-half

[Chris Wilson]

On Fri, Feb 19, 2016 at 02:10:44PM +0000, Tvrtko Ursulin wrote:
> On 19/02/16 12:29, Chris Wilson wrote:
> >Exactly, we want the iomap/vmap caching thingy first :) But the
> >retired work queue disappears as a fallout of your previous-context idea
> >anyway plus the fix to avoid the struct_mutex when freeing requests.
> 
> I did not get that working yet. I think it need N previous contexts
> pinned in a request, where N is equal to CSB size. Since most
> pessimistic thinking is we could get that many context complete
> events in a single interrupt.

The completion order is still the same as our execution order (it has to
be otherwise it violates our serialisation rules), so worst case is you
only need to keep the engine->last_context pinned along with active
references on the outstanding contexts (and those active references are
held by the following request).
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre