On Tue, Nov 01, 2016 at 08:54:09AM +0000, Tvrtko Ursulin wrote: > > On 01/11/2016 08:50, Chris Wilson wrote: > >On Tue, Nov 01, 2016 at 08:41:01AM +0000, Tvrtko Ursulin wrote: > >> > >>On 31/10/2016 10:26, Chris Wilson wrote: > >>>With full-ppgtt one of the main bottlenecks is the lookup of the VMA > >>>underneath the object. For execbuf there is merit in having a very fast > >>>direct lookup of ctx:handle to the vma using a hashtree, but that still > >>>leaves a large number of other lookups. One way to speed up the lookup > >>>would be to use a rhashtable, but that requires extra allocations and > >>>may exhibit poor worse case behaviour. An alternative is to use an > >>>embedded rbtree, i.e. no extra allocations and deterministic behaviour, > >>>but at the slight cost of O(lgN) lookups (instead of O(1) for > >>>rhashtable). The major of such tree will be very shallow and so not much > >>>slower, and still scales much, much better than the current unsorted > >>>list. > >>> > >>>References: https://bugs.freedesktop.org/show_bug.cgi?id=87726 > >>>Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > >> > >>I suggest leaving this out of the mini-series which fixes the > >>recently introduced bugs. > > > >Just review it now, it's a two year old bug that was impacting the test > >cases I was running... :-p Then we won't have to review it next week ;) > > I'll review it, just split it out please so the CI fire can be > extinguished first. Sure, I'm pushing the fixes as soon as they've been baked. There's a regression fix that builds upon this patch for multiple timelines (the linear walk in reservation_object is particularly nasty for scaling). -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
