Quoting Tvrtko Ursulin (2019-02-27 14:17:25) > > On 27/02/2019 10:44, Chris Wilson wrote: > > Quoting Tvrtko Ursulin (2019-02-27 10:29:43) > >> > >> On 26/02/2019 10:23, Chris Wilson wrote: > >>> As kmem_caches share the same properties (size, allocation/free behaviour) > >>> for all potential devices, we can use global caches. While this > >>> potential has worse fragmentation behaviour (one can argue that > >>> different devices would have different activity lifetimes, but you can > >>> also argue that activity is temporal across the system) it is the > >>> default behaviour of the system at large to amalgamate matching caches. > >>> > >>> The benefit for us is much reduced pointer dancing along the frequent > >>> allocation paths. > >>> > >>> v2: Defer shrinking until after a global grace period for futureproofing > >>> multiple consumers of the slab caches, similar to the current strategy > >>> for avoiding shrinking too early. > >> > >> I suggested to call i915_globals_park directly from __i915_gem_park for > >> symmetry with how i915_gem_unpark calls i915_globals_unpark. > >> i915_globals has it's own delayed setup so I don't think it benefits > >> from the double indirection courtesy of being called from shrink_caches. > > > > I replied I left that change until a later patch after the final > > conversions. Mostly so that we had a standalone patch to revert if the > > rcu_work turns out badly. In this patch, it was to be the simple > > translation over to global_shrink, except you asked for it to be truly > > global and so we needed another layer of counters. > > It's a hard sell I think. Because why even have rcu work now in this > case? You could make i915_globals_park just shrink if active counter > dropped to zero. I don't see a benefit in a temporary asymmetric solution. I did do just that in v1!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
