Example of memory ordering causing excitement in the real world

By: Konrad Schwarz (no.spam.delete@this.no.spam), July 23, 2015 2:38 pm
Room: Moderated Discussions
Michael S (already5chosen.delete@this.yahoo.com) on July 23, 2015 7:31 am wrote:
> I don't think you are correct about it.

Ok, so I looked at the ARM ACE specification, ARM IHI 0022D, which also specifies AXI4. ACE is a coherency protocol defined by ARM. Chapter C8 is on barrier transactions.

I can't say that I have fully digested the specification, but it does look like signaling for barriers is from masters (e.g., processor cores) to downstream interconnects only (including a handshake). To me, it looks like the set of memory accesses (transactions) affected by a (full) synchronization barrier is defined implicitly as the memory accesses that happen to have been issued by processors ahead of or after the barrier. Interconnects must not reorder these accesses across the barrier.

In other words, any store queues in other processors would not be affected by a processor issuing a full synchronization barrier, contrary to my previous assertion.

The interconnect does delay completing some access transactions in certain cases.
< Previous Post in ThreadNext Post in Thread >
TopicPosted ByDate
Cyclone Macro-op fusionMaynard Handley2015/07/05 05:01 PM
  Cyclone Macro-op fusionGabriele Svelto2015/07/06 01:11 AM
    Cyclone Macro-op fusionMaynard Handley2015/07/06 09:25 AM
      Cyclone Macro-op fusionWilco2015/07/06 10:17 AM
        Cyclone Macro-op fusionMaynard Handley2015/07/06 11:07 AM
          Cyclone Macro-op fusionMaynard Handley2015/07/06 11:55 AM
            Cyclone Macro-op fusionGabriele Svelto2015/07/07 01:49 AM
      Power8 branch conversionSHK2015/07/06 11:41 AM
        Power8 branch conversionMaynard Handley2015/07/06 12:01 PM
          Power8 branch conversionMaynard Handley2015/07/06 12:09 PM
        Benefit of dynamic hammock predicationPaul A. Clayton2015/07/06 02:02 PM
          Benefit of dynamic hammock predicationMaynard Handley2015/07/06 02:34 PM
            Benefit of dynamic hammock predicationEduardoS2015/07/06 06:56 PM
            Benefit of dynamic hammock predicationPatrick Chase2015/07/06 09:30 PM
          Benefit of dynamic hammock predicationLinus Torvalds2015/07/06 02:59 PM
            Benefit of dynamic hammock predicationWilco2015/07/06 03:35 PM
              Benefit of dynamic hammock predicationLinus Torvalds2015/07/06 04:25 PM
                Benefit of dynamic hammock predicationanon2015/07/06 08:02 PM
            Benefit of dynamic hammock predicationPatrick Chase2015/07/06 09:31 PM
              Benefit of dynamic hammock predicationanon2015/07/06 10:02 PM
              Benefit of dynamic hammock predicationMichael S2015/07/07 12:07 AM
              Benefit of dynamic hammock predicationLinus Torvalds2015/07/07 08:23 AM
                Benefit of dynamic hammock predicationPatrick Chase2015/07/07 09:49 AM
                  Benefit of dynamic hammock predicationSHK2015/07/07 10:34 AM
                  Benefit of dynamic hammock predicationMaynard Handley2015/07/07 11:00 AM
                    Benefit of dynamic hammock predicationExophase2015/07/07 12:26 PM
                      Benefit of dynamic hammock predicationWilco2015/07/07 03:54 PM
                      Benefit of dynamic hammock predicationMaynard Handley2015/07/07 04:25 PM
                    Benefit of dynamic hammock predicationPatrick Chase2015/07/07 01:32 PM
                    Benefit of dynamic hammock predicationMichael S2015/07/08 12:57 AM
                  Benefit of dynamic hammock predicationSylvain Collange2015/07/08 05:30 AM
                    Benefit of dynamic hammock predicationMaynard Handley2015/07/08 08:46 AM
                      Benefit of dynamic hammock predicationSylvain Collange2015/07/08 09:32 AM
                        Benefit of dynamic hammock predicationMaynard Handley2015/07/08 09:57 AM
                        Sadly, skewed associativity has not been broadly adoptedPaul A. Clayton2015/07/08 01:00 PM
                        Prediction quality of A8 and Intel (was Benefit of dynamic hammock predication)Maynard Handley2015/07/08 07:23 PM
                          Prediction quality of A8 and Intel (was Benefit of dynamic hammock predication)David Kanter2015/07/09 06:20 AM
                            Prediction quality of A8 and Intel (was Benefit of dynamic hammock predication)Maynard Handley2015/07/09 09:04 AM
                              Prediction quality of A8 and Intel (was Benefit of dynamic hammock predication)Tim McCaffrey2015/07/09 09:41 AM
                                Prediction quality of A8 and Intel (was Benefit of dynamic hammock predication)Patrick Chase2015/07/09 12:08 PM
                                  Prediction quality of A8 and Intel (was Benefit of dynamic hammock predication)Sylvain Collange2015/07/10 01:03 AM
                              Prediction quality of A8 and Intel (was Benefit of dynamic hammock predication)David Kanter2015/07/09 03:15 PM
                                Prediction quality of A8 and Intel (was Benefit of dynamic hammock predication)Maynard Handley2015/07/09 04:21 PM
                            Prediction quality of A8 and Intel (was Benefit of dynamic hammock predication)Patrick Chase2015/07/09 11:44 AM
                          Prediction quality of A8 and Intel (was Benefit of dynamic hammock predication)Patrick Chase2015/07/09 08:43 AM
                          Prediction quality of A8 and Intel (was Benefit of dynamic hammock predication)someone2015/07/10 04:43 AM
            Benefit of dynamic hammock predicationKonrad Schwarz2015/07/07 06:54 AM
            Benefit of dynamic hammock predicationdmcq2015/07/07 01:38 PM
              Benefit of dynamic hammock predicationLinus Torvalds2015/07/08 07:23 AM
                Benefit of dynamic hammock predicationdmcq2015/07/08 09:11 AM
                  Benefit of dynamic hammock predicationLinus Torvalds2015/07/08 12:38 PM
                    Example of memory ordering causing excitement in the real worldMark Roulo2015/07/08 03:54 PM
                      Example of memory ordering causing excitement in the real worlddmcq2015/07/09 03:37 AM
                        Example of memory ordering causing excitement in the real worldMark Roulo2015/07/09 07:24 AM
                          Example of memory ordering causing excitement in the real worlddmcq2015/07/09 09:09 AM
                          Example of memory ordering causing excitement in the real worldMaynard Handley2015/07/09 09:12 AM
                            Example of memory ordering causing excitement in the real worldLinus Torvalds2015/07/09 11:14 AM
                              Example of memory ordering causing excitement in the real worlddmcq2015/07/09 03:24 PM
                                Example of memory ordering causing excitement in the real worldSimon Farnsworth2015/07/10 12:07 PM
                                  Example of memory ordering causing excitement in the real worlddmcq2015/07/10 02:49 PM
                                    Example of memory ordering causing excitement in the real worldSimon Farnsworth2015/07/12 12:02 PM
                                      Example of memory ordering causing excitement in the real worlddmcq2015/07/13 04:03 AM
                                        Example of memory ordering causing excitement in the real worldMichael S2015/07/13 04:19 AM
                                        Example of memory ordering causing excitement in the real worldSimon Farnsworth2015/07/14 12:21 PM
                                          Example of memory ordering causing excitement in the real worlddmcq2015/07/14 01:54 PM
                                            Example of memory ordering causing excitement in the real worldSimon Farnsworth2015/07/15 12:13 PM
                                              Example of memory ordering causing excitement in the real worlddmcq2015/07/15 02:43 PM
                                                Example of memory ordering causing excitement in the real worldSimon Farnsworth2015/07/16 11:41 AM
                                                  Example of memory ordering causing excitement in the real worldWilco2015/07/17 12:57 PM
                                                    Example of memory ordering causing excitement in the real worldLinus Torvalds2015/07/17 03:29 PM
                                                      Example of memory ordering causing excitement in the real worlddmcq2015/07/18 03:07 AM
                                          Example of memory ordering causing excitement in the real worldJouni Osmala2015/07/16 02:52 AM
                                            Example of memory ordering causing excitement in the real worldSimon Farnsworth2015/07/16 12:05 PM
                                              Example of memory ordering causing excitement in the real worldJouni Osmala2015/07/17 12:18 AM
                                                ISA support for bound checkingMichael S2015/07/17 03:51 AM
                                                  ISA support for bound checkingEtienne2015/07/17 05:39 AM
                                                  MPX on SkylakeMark Roulo2015/07/17 07:19 AM
                                                    MPX on SkylakeMichael S2015/07/17 07:44 AM
                                                      MPX on SkylakeMark Roulo2015/07/17 08:03 AM
                                  Example of memory ordering causing excitement in the real worldanon2015/07/12 02:42 AM
                                    Example of memory ordering causing excitement in the real worlddmcq2015/07/12 09:27 AM
                                    Example of memory ordering causing excitement in the real worldLinus Torvalds2015/07/12 10:24 AM
                                      Example of memory ordering causing excitement in the real worldEduardoS2015/07/12 10:53 AM
                                        Example of memory ordering causing excitement in the real worldLinus Torvalds2015/07/12 12:07 PM
                                          Example of memory ordering causing excitement in the real worldanon2015/07/12 06:52 PM
                                            Example of memory ordering causing excitement in the real worldLinus Torvalds2015/07/13 10:05 AM
                                              Example of memory ordering causing excitement in the real worlddmcq2015/07/13 11:20 AM
                                                Example of memory ordering causing excitement in the real worldLinus Torvalds2015/07/13 12:46 PM
                                                  Example of memory ordering causing excitement in the real worldMaynard Handley2015/07/13 01:10 PM
                                                    Example of memory ordering causing excitement in the real worldanon2015/07/13 07:51 PM
                                                    Simple cores justifying weak ordering?Paul A. Clayton2015/07/14 08:01 AM
                                                      David's Paul A. Clayton2015/07/14 08:37 AM
                                                      David's 2015-07-12 10:34 post confirmed some of that (NT)Paul A. Clayton2015/07/14 08:39 AM
                                                    Example of memory ordering causing excitement in the real worldEtienne2015/07/17 12:15 AM
                                                  Example of memory ordering causing excitement in the real worlddmcq2015/07/13 01:14 PM
                                                  Reality is even worseTerry Gray2015/07/13 05:05 PM
                                                    Reality is even worseKonrad Schwarz2015/07/20 11:13 PM
                                                  A simple CAS/MCAS semantics2015/07/15 11:54 AM
                                                    A simple CAS/MCAS semanticsLinus Torvalds2015/07/15 12:55 PM
                                                    A simple CAS/MCAS semanticsEduardoS2015/07/15 01:31 PM
                                                Example of memory ordering causing excitement in the real worldsylt2015/07/13 01:19 PM
                                                  Example of memory ordering causing excitement in the real worlddmcq2015/07/13 02:24 PM
                                                    Example of memory ordering causing excitement in the real worldEduardoS2015/07/13 03:48 PM
                                                      Example of memory ordering causing excitement in the real worldMaynard Handley2015/07/13 06:18 PM
                                                        Example of memory ordering causing excitement in the real worldEduardoS2015/07/13 06:57 PM
                                                      Example of memory ordering causing excitement in the real worldanon2015/07/13 08:01 PM
                                                    What high level languages do you have in mind?Mark Roulo2015/07/13 04:00 PM
                                                      What high level languages do you have in mind?dmcq2015/07/14 05:54 AM
                                                  Example of memory ordering causing excitement in the real worldWilco2015/07/13 03:36 PM
                                                    Example of memory ordering causing excitement in the real worldEduardoS2015/07/13 03:56 PM
                                                      Example of memory ordering causing excitement in the real worldanon2015/07/13 05:43 PM
                                                        Example of memory ordering causing excitement in the real worldEduardoS2015/07/13 07:11 PM
                                                          Example of memory ordering causing excitement in the real worldanon2015/07/13 08:07 PM
                                      Example of memory ordering causing excitement in the real worldMaynard Handley2015/07/12 11:32 AM
                                        Example of memory ordering causing excitement in the real worldEduardoS2015/07/12 12:35 PM
                                        Example of memory ordering causing excitement in the real worldLinus Torvalds2015/07/12 12:38 PM
                                          Example of memory ordering causing excitement in the real worldEduardoS2015/07/12 05:47 PM
                                            Example of memory ordering causing excitement in the real worldNoSpammer2015/07/13 11:34 AM
                                              Example of memory ordering causing excitement in the real worldWilco2015/07/13 03:50 PM
                                                Example of memory ordering causing excitement in the real worldNoSpammer2015/07/14 01:02 PM
                                                  Example of memory ordering causing excitement in the real worldanon2015/07/14 08:37 PM
                                                    Example of memory ordering causing excitement in the real worldMichael S2015/07/15 12:19 AM
                                                      Example of memory ordering causing excitement in the real worldanon2015/07/15 01:26 AM
                                                        Example of memory ordering causing excitement in the real worldNoSpammer2015/07/15 06:05 AM
                                                          Example of memory ordering causing excitement in the real worlddmcq2015/07/15 07:04 AM
                                                            Example of memory ordering causing excitement in the real worldMichael S2015/07/15 07:29 AM
                                                              Example of memory ordering causing excitement in the real worlddmcq2015/07/15 09:09 AM
                                                              Can string ops use microarchitectural state?Paul A. Clayton2015/07/16 08:33 AM
                                                                Can string ops use microarchitectural state?rwessel2015/07/16 12:00 PM
                                                                  Can string ops use microarchitectural state?Paul A. Clayton2015/07/16 05:16 PM
                                                                    Can string ops use microarchitectural state?rwessel2015/07/16 08:34 PM
                                                                      Can string ops use microarchitectural state?Michael S2015/07/17 04:39 AM
                                                                        Can string ops use microarchitectural state?rwessel2015/07/17 08:02 AM
                                                                Consider interrupt followed by task preemptionMichael S2015/07/16 03:31 PM
                                                                  Consider interrupt followed by task preemptionPaul A. Clayton2015/07/16 05:23 PM
                                                            Example of memory ordering causing excitement in the real worldNoSpammer2015/07/15 11:50 AM
                                                              Example of memory ordering causing excitement in the real worldLinus Torvalds2015/07/15 01:27 PM
                                                                Example of memory ordering causing excitement in the real worldNoSpammer2015/07/15 02:14 PM
                                                                  Example of memory ordering causing excitement in the real worldLinus Torvalds2015/07/15 04:42 PM
                                                      Example of memory ordering causing excitement in the real worldNoSpammer2015/07/15 01:44 AM
                                                    Example of memory ordering causing excitement in the real worldLinus Torvalds2015/07/15 01:17 PM
                                                      Example of memory ordering causing excitement in the real worldWilco2015/07/15 01:43 PM
                                                        Example of memory ordering causing excitement in the real worldanon2015/07/15 04:45 PM
                                                        Example of memory ordering causing excitement in the real worldLinus Torvalds2015/07/15 05:35 PM
                                                          Example of memory ordering causing excitement in the real worlddmcq2015/07/16 01:46 AM
                                                            Example of memory ordering causing excitement in the real worlddmcq2015/07/16 01:49 AM
                                        Example of memory ordering causing excitement in the real worldKonrad Schwarz2015/07/21 06:15 AM
                                      Example of memory ordering causing excitement in the real worldanon2015/07/12 06:42 PM
                                        Example of memory ordering causing excitement in the real worldanon2015/07/12 08:48 PM
                                        Example of memory ordering causing excitement in the real worldDavid Kanter2015/07/12 09:34 PM
                                          Example of memory ordering causing excitement in the real worldMichael S2015/07/13 12:51 AM
                                            Example of memory ordering causing excitement in the real worldDavid Kanter2015/07/13 07:31 AM
                                          Example of memory ordering causing excitement in the real worldanon2015/07/13 05:05 AM
                                            Example of memory ordering causing excitement in the real worldGabriele Svelto2015/07/17 04:40 AM
                                          Example of memory ordering causing excitement in the real worlddmcq2015/07/13 07:09 AM
                                        Example of memory ordering causing excitement in the real worldanon2015/07/13 06:46 AM
                                          Example of memory ordering causing excitement in the real worldanon2015/07/14 03:12 AM
                                        Example of memory ordering causing excitement in the real worlddmcq2015/07/15 02:51 AM
                                          Example of memory ordering causing excitement in the real worldanon2015/07/15 03:38 AM
                                            Example of memory ordering causing excitement in the real worlddmcq2015/07/15 05:21 AM
                                      Store queues in POWER/PowerPC processorsGabriele Svelto2015/07/16 12:55 AM
                                        Not sure about that conclusionDavid Kanter2015/07/16 06:34 AM
                                          The POWER4 had the same structureGabriele Svelto2015/07/17 04:20 AM
                                        Committing stores in program orderPaul A. Clayton2015/07/16 12:35 PM
                                          Committing stores in program orderMaynard Handley2015/07/17 11:52 AM
                                      Example of memory ordering causing excitement in the real worldKonrad Schwarz2015/07/20 03:44 AM
                                        Example of memory ordering causing excitement in the real worldanon2015/07/20 06:29 AM
                                          Example of memory ordering causing excitement in the real worldKonrad Schwarz2015/07/20 11:08 PM
                                            Example of memory ordering causing excitement in the real worlddmcq2015/07/21 12:27 AM
                                            Example of memory ordering causing excitement in the real worldMichael S2015/07/21 02:11 AM
                                              Example of memory ordering causing excitement in the real worldKonrad Schwarz2015/07/21 04:24 AM
                                            Example of memory ordering causing excitement in the real worldanon2015/07/21 05:22 AM
                                              Example of memory ordering causing excitement in the real worldKonrad Schwarz2015/07/21 06:36 AM
                                                Example of memory ordering causing excitement in the real worldanon2015/07/21 07:25 AM
                                              Example of memory ordering causing excitement in the real worldanon2015/07/21 07:17 AM
                                                Example of memory ordering causing excitement in the real worldanon2015/07/21 08:50 AM
                                                Example of memory ordering causing excitement in the real worldGabriele Svelto2015/07/21 11:46 AM
                                                Example of memory ordering causing excitement in the real worldKonrad Schwarz2015/07/21 11:35 PM
                                                  Example of memory ordering causing excitement in the real worldKonrad Schwarz2015/07/22 12:37 AM
                                                  Example of memory ordering causing excitement in the real worldanon2015/07/23 02:17 AM
                                                    Example of memory ordering causing excitement in the real worldKonrad Schwarz2015/07/23 03:59 AM
                                                      Example of memory ordering causing excitement in the real worldMichael S2015/07/23 06:31 AM
                                                        Example of memory ordering causing excitement in the real worldKonrad Schwarz2015/07/23 02:38 PM
                                                          Example of memory ordering causing excitement in the real worldKonrad Schwarz2015/07/23 10:44 PM
                                                            Example of memory ordering causing excitement in the real worlddmcq2015/07/24 12:08 AM
                                    Example of memory ordering causing excitement in the real worlddmcq2015/07/13 06:27 AM
                          Example of memory ordering causing excitement in the real worldKonrad Schwarz2015/07/16 04:11 AM
                      Example of memory ordering causing excitement in the real worldAnonymousse2015/07/16 04:07 AM
          Benefit of dynamic hammock predicationsomeotherdude2015/07/06 04:12 PM
            Benefit of dynamic hammock predicationMichael S2015/07/07 12:19 AM
          Benefit of dynamic hammock predicationPatrick Chase2015/07/06 09:20 PM
            SIMD predication is also helpful, of course (NT)Paul A. Clayton2015/07/07 06:45 AM
        Power8 branch conversionGabriele Svelto2015/07/07 01:50 AM
          isel works for storesPaul A. Clayton2015/07/07 06:43 AM
            isel works for storesPatrick Chase2015/07/07 10:08 AM
            isel DOES NOT work for storessomeotherdude2015/07/07 03:01 PM
              isel DOES NOT work for storesWilco2015/07/07 03:40 PM
              Yes it doesPatrick Chase2015/07/07 10:14 PM
                Yes it doesvvid2015/07/08 08:51 AM
            You don't need isel eitherGabriele Svelto2015/07/08 01:01 AM
              You don't need isel eitherPaul A. Clayton2015/07/08 03:46 AM
                You don't need isel eitherGabriele Svelto2015/07/08 04:22 AM
Reply to this Topic
Name:
Email:
Topic:
Body: No Text
How do you spell green?