Haskell Compilation Improvement

By: anon (anon.delete@this.anon.com), April 11, 2013 10:50 am
Room: Moderated Discussions
Eric Bron (eric.bron.delete@this.zvisuel.privatefortest.com) on April 11, 2013 10:30 am wrote:
> > However if you traverse larger and more complex objects, for example, you may
> > have known location of several memory addresses inherently in the object.
> >
> > object = list.ptr;
> > prefetch(object->sub_object);
> > prefetch(&object->far_from_start);
> > prefetch(object->list.next);
> > /*
> > * At this point, you have 3 memops in flight. Even if do_something
> > * has to wait for one of them, you still get the MLP which probably
> > * can not be found by hardware prefetchers, and quite possibly will
> > * not be found so early by the OOOE machine.
> > */
> > do_otherthing(object->sub_object);
> > do_something(&object->far_from_start);
> > object = object->list.next;
> > } while (object);
> >
> > And now even better, we'll be able to prefetchw, which helps the above pattern quite a lot.
>
> it remember a lot of tests I have done in the past, with frustrating the fact is that you typically must fetch several nodes (10 nodes or more) in advance for simple processing
> per node and in case of complex processing per node you're probably not latency bound, there is probably some

It's not necessarily complex processing more complex object relationship or larger objects.

> workloads in between where it helps, I'll be interested to hear about the *actual* speedups people get

Me too. I don't have recent numbers or able to share code. But a simple amount of searching showed up this:

http://kt1.osuosl.org/mailarchive/linux-netdev/2010/12/4/6290897/thread

Which is the kind of pattern I advocate -- when you are working on some object and have a sub-object (or sub-data) in there.

It gave a 4.6% speedup, for just adding a single prefetch instruction and the speedup is for the wider benchmark, not just the data structure traversal in isolation.
< Previous Post in ThreadNext Post in Thread >
TopicPosted ByDate
Haskell Compilation ImprovementSymmetry2013/04/09 10:41 AM
  Haskell Compilation ImprovementEric Bron2013/04/09 11:56 AM
  Haskell Compilation ImprovementLinus Torvalds2013/04/09 12:03 PM
    Haskell Compilation ImprovementEduardoS2013/04/09 12:20 PM
      Haskell Compilation ImprovementLinus Torvalds2013/04/09 12:31 PM
        Haskell Compilation ImprovementEduardoS2013/04/09 12:49 PM
    Haskell Compilation Improvement2013/04/11 01:36 AM
      Haskell Compilation ImprovementEric Bron2013/04/11 03:58 AM
        Haskell Compilation ImprovementBrendan2013/04/11 07:06 AM
          Haskell Compilation ImprovementSymmetry2013/04/11 07:45 AM
            Haskell Compilation ImprovementBrendan2013/04/11 11:31 AM
          Haskell Compilation ImprovementEric Bron2013/04/11 08:57 AM
            Haskell Compilation ImprovementBrendan2013/04/11 11:26 AM
              Haskell Compilation ImprovementEric Bron2013/04/11 11:36 AM
                Haskell Compilation ImprovementBrendan2013/04/11 05:00 PM
                  Haskell Compilation ImprovementDavid Kanter2013/04/11 08:50 PM
                    Software prefetching in JVMsGabriele Svelto2013/04/12 03:31 PM
                  Haskell Compilation ImprovementEric Bron2013/04/12 09:12 AM
                    Haskell Compilation ImprovementBrendan2013/04/12 11:40 AM
                      Haskell Compilation ImprovementEric Bron2013/04/12 12:15 PM
                        Haskell Compilation ImprovementBrendan2013/04/12 03:34 PM
                          Haskell Compilation ImprovementEric Bron2013/04/12 10:44 PM
                            Haskell Compilation ImprovementBrendan2013/04/13 02:20 AM
                              Haskell Compilation ImprovementEric Bron2013/04/13 02:32 AM
                                Haskell Compilation ImprovementBrendan2013/04/13 10:18 AM
                                  Haskell Compilation ImprovementEric Bron2013/04/14 01:04 AM
                          Haskell Compilation ImprovementEric Bron2013/04/15 08:34 AM
                            Haskell Compilation ImprovementBrendan2013/04/16 03:26 PM
                              Prefetch compilation testsEric Bron2013/04/21 12:52 AM
        Haskell Compilation Improvementanon2013/04/11 07:14 AM
          Haskell Compilation ImprovementMichael S2013/04/11 07:27 AM
            Haskell Compilation Improvementanon2013/04/11 08:25 AM
              Haskell Compilation ImprovementMichael S2013/04/11 08:37 AM
                Haskell Compilation Improvementbakaneko2013/04/11 09:39 AM
                  Haskell Compilation ImprovementEric Bron2013/04/11 10:08 AM
                    Haskell Compilation Improvementbakaneko2013/04/11 10:36 AM
                    Haskell Compilation Improvementanon2013/04/11 10:54 AM
                      Haskell Compilation ImprovementEric Bron2013/04/11 11:10 AM
                        Haskell Compilation Improvementanon2013/04/11 11:18 AM
                          Haskell Compilation ImprovementEric Bron2013/04/11 11:27 AM
                            Haskell Compilation Improvementanon2013/04/11 12:02 PM
                              Haskell Compilation ImprovementEric Bron2013/04/11 12:09 PM
                                Haskell Compilation ImprovementEric Bron2013/04/11 12:12 PM
                                Haskell Compilation Improvementanon2013/04/11 12:14 PM
                                  Haskell Compilation ImprovementEric Bron2013/04/11 12:30 PM
                                    Haskell Compilation Improvementanon2013/04/11 11:30 PM
                                      Haskell Compilation ImprovementEric Bron2013/04/12 09:25 AM
                                        Haskell Compilation Improvementanon2013/04/12 07:12 PM
                                          Haskell Compilation ImprovementEric Bron2013/04/12 10:51 PM
                                  Prefetch *hints*Konrad Schwarz2013/04/12 08:24 AM
                        Haskell Compilation ImprovementLinus Torvalds2013/04/11 12:56 PM
                          Inherent advantage of software prefetchJouni Osmala2013/04/11 09:41 PM
                            Inherent advantage of software prefetchSeni2013/04/13 03:40 AM
                            Another example: software scatter gather (NT)Megol2013/04/14 02:39 AM
                          Haskell Compilation ImprovementMaynard Handley2013/12/31 05:26 PM
                            Haskell Compilation ImprovementTREZA2013/12/31 05:44 PM
                              Haskell Compilation ImprovementMaynard Handley2013/12/31 07:49 PM
                                Haskell Compilation Improvementanon2013/12/31 10:39 PM
                                  Haskell Compilation ImprovementMaynard Handley2014/01/01 02:04 AM
                                  Haskell Compilation Improvementbakaneko2014/01/01 05:31 AM
                                Haskell Compilation ImprovementGabriele Svelto2014/01/02 07:57 AM
                                  Haskell Compilation ImprovementMichael S2014/01/02 08:37 AM
                                    Haskell Compilation ImprovementGabriele Svelto2014/01/02 10:09 AM
                                    Haskell Compilation ImprovementTREZA2014/01/02 12:43 PM
                            Haskell Compilation ImprovementMaynard Handley2013/12/31 06:07 PM
                            Future core architectures. (Was Haskell Compilation Improvement)Maynard Handley2014/01/03 12:06 AM
                              Speculative multi-threadingDavid Kanter2014/01/03 02:12 AM
                                Speculative multi-threadingMaynard Handley2014/01/03 05:01 AM
                              Future core architectures. (Was Haskell Compilation Improvement)Seni2014/01/03 01:09 PM
                              Future core architectures. (Was Haskell Compilation Improvement)Linus Torvalds2014/01/03 01:27 PM
                            Haskell Compilation ImprovementKonrad Schwarz2014/01/04 09:38 AM
              Haskell Compilation ImprovementEric Bron2013/04/11 09:23 AM
          Haskell Compilation ImprovementEric Bron2013/04/11 08:50 AM
            Haskell Compilation ImprovementEugene Nalimov2013/04/11 09:20 AM
              Haskell Compilation ImprovementEric Bron2013/04/11 09:28 AM
                Haskell Compilation ImprovementEduardoS2013/04/11 07:30 PM
            Haskell Compilation Improvementanon2013/04/11 10:19 AM
              Haskell Compilation ImprovementEric Bron2013/04/11 10:30 AM
                Haskell Compilation Improvementanon2013/04/11 10:50 AM
                  Haskell Compilation ImprovementEric Bron2013/04/11 11:03 AM
                    Haskell Compilation Improvementanon2013/04/11 11:16 AM
                      Haskell Compilation ImprovementEric Bron2013/04/11 11:24 AM
                        Haskell Compilation Improvementanon2013/04/11 12:09 PM
                          Haskell Compilation ImprovementEric Bron2013/04/11 12:43 PM
                            Haskell Compilation Improvementanon2013/04/11 11:27 PM
                              Haskell Compilation ImprovementEric Bron2013/04/12 12:15 AM
                                Haskell Compilation Improvementanon2013/04/12 07:14 PM
                                  Haskell Compilation ImprovementEric Bron2013/04/12 11:01 PM
                      Haskell Compilation ImprovementLinus Torvalds2013/04/11 01:05 PM
                        Haskell Compilation Improvementanon2013/04/11 10:42 PM
                        Haskell Compilation ImprovementRobert David Graham2013/04/12 02:12 PM
        Software prefetch architecturePaul A. Clayton2013/04/11 08:54 AM
          Software prefetch architectureEric Bron2013/04/11 09:06 AM
            Software prefetch architectureMegol2013/04/15 11:03 AM
              Software prefetch architectureEric Bron2013/04/15 11:30 AM
  low barMichael S2013/04/09 04:38 PM
Reply to this Topic
Name:
Email:
Topic:
Body: No Text
How do you spell avocado?