Intel RTM and HLE is a success (is it?)

By: Andrey (andrey.semashev.delete@this.gmail.com), March 31, 2021 4:27 am
Room: Moderated Discussions
Foo_ (foo.delete@this.nomail.com) on March 31, 2021 1:16 am wrote:
> Ganon (anon.delete@this.gmail.com) on March 30, 2021 5:22 pm wrote:
> >
> > Other than the some initial bugs and possible side channel issues
> > (which are not a relevant security threat in many contexts); has Intel
> > failed with HTM/TLE? Many commercial databases are making active use of it;
> > it greatly simplifies the writing of scalable concurrent data structures.
>
> Which "commercial databases" are making active use of it, and for which kind of benefit?
>
> Also, how would it "simplify the writing of scalable concurrent data structures" since you still
> need to write (and optimize) the non-HTM/TLE codepath for all CPUs that don't support it?

You obviously have to write non-transactional path, and it will have its pitfalls, but the point is that you could have better best-case and average performance with TSX. For example, where you would traditionally lock the whole data structure, the transactional path could succeed without locking and with multiple threads working on the data structure in parallel.

And I should note that basically any multithreaded program on Linux could benefit from TSX, since it is supported in pthreads implementation in glibc. Not that I personally find that making pthread_mutex_t transactional by default is a good idea, but this is currently the case, and in some cases this can reap benefits.

> And according to Wikipedia:
>
> "According to Intel 64 and IA-32 Architectures Optimization Reference Manual from May 2020, Volume 1, Chapter
> 2.5 Intel Instruction Set Architecture And Features Removed, HLE has been removed from Intel products released
> in 2019 and later. RTM is not documented as removed. However, Intel 10th generation Comet Lake and Ice Lake
> CPUs, which were released in 2020, do not support TSX/TSX-NI, including both HLE and RTM."

Given that Intel is introducing TSXLDTRK in Sapphire Rapids, it looks like they're segmenting TSX into server and possibly HEDT parts. Which would be a stupid thing to do, it's the AVX-512 situation all over again.

I seem to remember a note in some Intel docs that TSX won't be supported in Alder Lake when Intel Hybrid technology is active, which could imply that it will be supported when Hybrid technology is disabled. But I can't find that note now, so if it existed it is probably removed now. Which means Alder Lake probably won't support TSX either. In that case, alas, Intel fails again.
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TopicPosted ByDate
Armv9 officially announcedJon Masters2021/03/30 10:41 AM
  Armv9 officially announcedGabriele Svelto2021/03/30 12:27 PM
    HTM and TLEFoo_2021/03/30 12:31 PM
      HTM and TLEdmcq2021/03/30 02:03 PM
      Intel RTM and HLE is a successGanon2021/03/30 04:22 PM
        Intel RTM and HLE is a success (is it?)Foo_2021/03/31 12:16 AM
          Intel RTM and HLE was an abject failureanonymou52021/03/31 02:04 AM
          Intel RTM and HLE is a success (is it?)Andrey2021/03/31 04:27 AM
            Intel RTM and HLE is a success (is it?)Foo_2021/03/31 04:58 AM
              Intel RTM and HLE is a success (is it?)Andrey2021/03/31 06:45 AM
                Intel RTM and HLE is a success (is it?)Foo_2021/03/31 08:32 AM
                  Intel RTM and HLE is a success (is it?)Andrey2021/03/31 08:57 AM
                    Intel RTM and HLE is a success (is it?)anonymou52021/03/31 09:39 AM
                      ^ feel free to delete this one -- broken HTML there (NT)anonymou52021/03/31 09:40 AM
                      Intel RTM and HLE is a success (is it?)Andrey2021/03/31 09:47 AM
                    Intel RTM and HLE is a success (is it?)anonymou52021/03/31 09:40 AM
                Intel RTM and HLE is a success (is it?)Ganon2021/03/31 08:58 AM
                  Intel RTM and HLE is a success (is it?)anonymou52021/03/31 09:42 AM
                  Intel RTM and HLE is a success (is it?)Linus Torvalds2021/03/31 10:54 AM
                    Intel RTM and HLE is a success (is it?)Linus Torvalds2021/03/31 11:00 AM
                      Any idea about IBM?Mark Roulo2021/03/31 11:15 AM
                        Any idea about IBM?Linus Torvalds2021/03/31 11:37 AM
                          Any idea about IBM?dmcq2021/03/31 02:04 PM
                            Any idea about IBM?Linus Torvalds2021/03/31 03:44 PM
                              A non straw man view of hardware transactional memoryGanon2021/03/31 06:52 PM
                                A non straw man view of hardware transactional memoryanon22021/03/31 10:03 PM
                                  A non straw man view of hardware transactional memoryCarson2021/04/02 12:11 AM
                                    A non straw man view of hardware transactional memoryanon22021/04/02 04:28 AM
                              IBM zArch TM - guaranteed progressDavid Kanter2021/03/31 07:37 PM
                              Any idea about IBM?Andrey2021/03/31 10:31 PM
                                Any idea about IBM?Linus Torvalds2021/04/01 09:54 AM
                                  Any idea about IBM?Andrey2021/04/02 11:50 AM
                        Any idea about IBM?someone2021/03/31 11:02 PM
                      Intel RTM and HLE is a success (is it?)anon22021/03/31 02:46 PM
                        Intel RTM and HLE is a success (is it?)Linus Torvalds2021/03/31 04:08 PM
                          Leaving it to software is tricky!David Kanter2021/03/31 07:41 PM
                            And a hardware predicttor needs access to fallback timingCarson2021/04/01 10:13 PM
                              Hardware fallback pathAnon2021/04/02 09:51 AM
                              And a hardware predicttor needs access to fallback timingLinus Torvalds2021/04/03 09:41 AM
                                And a hardware predicttor needs access to fallback timingLinus Torvalds2021/04/03 10:11 AM
                                  And a hardware predicttor needs access to fallback timingsr2021/04/03 10:30 AM
                                    And a hardware predicttor needs access to fallback timingLinus Torvalds2021/04/03 11:14 AM
                                      And a hardware predicttor needs access to fallback timingsr2021/04/03 11:39 AM
                                        And a hardware predicttor needs access to fallback timingAnon2021/04/03 01:08 PM
                                          And a hardware predicttor needs access to fallback timingsr2021/04/03 01:33 PM
                                            And a hardware predicttor needs access to fallback timingdmcq2021/04/04 04:35 AM
                                        And a hardware predicttor needs access to fallback timingLinus Torvalds2021/04/03 01:22 PM
                                          Transactional memory isn't exclusive to lockingsr2021/04/03 11:17 PM
                                            Transactional memory isn't exclusive to lockingAspect of Anonimity2021/04/04 02:49 AM
                                            Transactional memory isn't exclusive to lockingAndrey2021/04/04 03:58 AM
                                              Transactional memory isn't exclusive to lockingsr2021/04/04 09:10 AM
                                                Transactional memory isn't exclusive to lockingAndrey2021/04/04 09:33 AM
                                                  Transactional memory isn't exclusive to lockingsr2021/04/05 01:41 AM
                                      And a hardware predicttor needs access to fallback timingGeertB2021/04/04 06:08 PM
                            Leaving it to software is tricky!Andrey2021/04/02 02:00 PM
                          Intel RTM and HLE is a success (is it?)@never_released2021/04/01 07:21 AM
                            Intel RTM and HLE is a success (is it?)@never_released2021/04/01 07:30 AM
                            Intel RTM and HLE is a success (is it?)Linus Torvalds2021/04/01 09:00 AM
                              Intel RTM and HLE is a success (is it?)dmcq2021/04/01 09:35 AM
                                Intel RTM and HLE is a success (is it?)Linus Torvalds2021/04/01 09:59 AM
                                  Is HTM actually in ARMv9?dncq2021/04/01 10:26 AM
                                    Is HTM actually in ARMv9?Linus Torvalds2021/04/01 11:13 AM
                              Intel RTM and HLE is a success (is it?)Jörn Engel2021/04/01 08:15 PM
                          Intel RTM and HLE is a success (is it?)---2021/04/02 09:00 AM
                      Intel RTM and HLE is a success (is it?)Jon Masters2021/04/01 09:56 AM
                        RockMichael S2021/04/01 11:29 AM
            Intel RTM and HLE is a success (is it?)Linus Torvalds2021/03/31 10:50 AM
              Intel RTM and HLE is a success (is it?)anon22021/03/31 02:57 PM
                Intel RTM and HLE is a success (is it?)anon32021/03/31 03:09 PM
          Intel RTM and HLE is a success (is it?)someone2021/03/31 10:56 PM
            Intel RTM and HLE is a success (is it?)someone2021/03/31 11:21 PM
              Intel RTM and HLE is a success (is it?)none2021/04/01 03:31 AM
                Intel RTM and HLE is a success (is it?)anonymou52021/04/01 08:24 AM
                  Intel RTM and HLE is a success (is it?)anony2021/04/01 09:26 AM
                  Intel RTM and HLE is a success (is it?)none2021/04/01 10:20 AM
                Intel RTM and HLE is a success (is it?)Brendan2021/04/01 04:23 PM
                  Intel RTM and HLE is a success (is it?)Adrian2021/04/02 12:03 AM
      Transactional memory similarity to garbage collectionPaul A. Clayton2021/04/05 12:53 PM
        Maybe notMark Roulo2021/04/05 02:07 PM
        Transactional memory similarity to garbage collectionAnon2021/04/05 02:14 PM
        No conflict between theory and practiceAspect of Anonimity2021/04/05 06:57 PM
          No conflict between theory and practiceNoSpammer2021/04/05 08:38 PM
            No conflict between theory and practicedmcq2021/04/06 06:05 AM
              No conflict between theory and practicesr2021/04/06 08:22 AM
                No conflict between theory and practiceBen LaHaise2021/04/06 02:43 PM
                  No conflict between theory and practicesr2021/04/07 08:42 AM
                    No conflict between theory and practiceAnon2021/04/07 09:06 AM
                    No conflict between theory and practiceLinus Torvalds2021/04/07 09:35 AM
                      No conflict between theory and practicesr2021/04/07 11:34 AM
                        If HTM were well implemented, nobody would complain (NT)Anon2021/04/07 11:54 AM
                          If HTM were well implemented, nobody would complaindmcq2021/04/07 02:36 PM
                            If HTM were well implemented, nobody would complainAnon2021/04/07 03:04 PM
                          If HTM were well implemented, nobody would complain---2021/04/08 08:37 AM
                        No conflict between theory and practiceLinus Torvalds2021/04/07 12:20 PM
                          No conflict between theory and practiceAndrey2021/04/07 01:32 PM
                            No conflict between theory and practicedmcq2021/04/07 02:32 PM
                              No conflict between theory and practiceanonymou52021/04/07 03:26 PM
                              No conflict between theory and practiceAndrey2021/04/07 04:54 PM
                                No conflict between theory and practiceLinus Torvalds2021/04/08 07:41 AM
                                  No conflict between theory and practiceAndrey2021/04/08 08:12 AM
                                  No conflict between theory and practiceRobert Williams2021/04/08 08:15 AM
                                    No conflict between theory and practiceLinus Torvalds2021/04/08 08:56 AM
                                      No conflict between theory and practiceRobert Williams2021/04/08 06:50 PM
                                        No conflict between theory and practiceLinus Torvalds2021/04/09 08:25 AM
                                          TSX for all?Robert Williams2021/04/09 11:46 AM
                                            It helps adoption when developers can run the code an their machines.Mark Roulo2021/04/09 11:54 AM
                                              It helps adoption when developers can run the code an their machines.me2021/04/09 01:21 PM
                                                It helps adoption when developers can run the code an their machines.Andrey2021/04/10 06:08 AM
                                                  It helps adoption when developers can run the code an their machines.me2021/04/10 11:43 AM
                                                    It helps adoption when developers can run the code an their machines.Robert Williams2021/04/10 06:05 PM
                                                      It helps adoption when developers can run the code an their machines.Andrey2021/04/11 12:42 AM
                                                        It helps adoption when developers can run the code an their machines.Michael S2021/04/11 03:23 AM
                                              It helps adoption when developers can run the code an their machines.Robert Williams2021/04/10 07:24 AM
                                                It helps adoption when developers can run the code an their machines.Andrey2021/04/10 09:36 AM
                                                  It helps adoption when developers can run the code an their machines.Michael S2021/04/10 09:58 AM
                                                    It helps adoption when developers can run the code an their machines.Robert Williams2021/04/10 10:42 AM
                                                    It helps adoption when developers can run the code an their machines.Brendan2021/04/10 10:27 PM
                                                      It helps adoption when developers can run the code an their machines.Michael S2021/04/11 02:34 AM
                                                        It helps adoption when developers can run the code an their machines.Brendan2021/04/11 03:18 PM
                                            TSX for all?wumpus2021/04/09 12:10 PM
                                            TSX for all?Linus Torvalds2021/04/09 02:03 PM
                                              [CLICK BAIT?] Torvalds to recommend arm64!anonymous22021/04/09 02:17 PM
                                              TSX for all?Linus Torvalds2021/04/09 02:22 PM
                                                amen! (NT)anonymou52021/04/09 04:42 PM
                                            TSX for all?Emil Briggs2021/04/10 04:52 AM
                                              TSX for all?Michael S2021/04/10 10:13 AM
                                                TSX for all?Brendan2021/04/10 10:05 PM
                                          No conflict between theory and practiceanonymouse2021/04/09 02:02 PM
                            No conflict between theory and practiceLinus Torvalds2021/04/07 04:12 PM
                              No conflict between theory and practiceAndrey2021/04/07 04:33 PM
                                No conflict between theory and practiceanon22021/04/07 07:12 PM
                                  No conflict between theory and practiceAndrey2021/04/07 11:29 PM
                                    No conflict between theory and practiceAnon2021/04/07 11:50 PM
                                    No conflict between theory and practiceanon22021/04/07 11:52 PM
                                      No conflict between theory and practiceAndrey2021/04/08 01:41 AM
                                        No conflict between theory and practiceAdrian2021/04/08 02:09 AM
                                          No conflict between theory and practiceAndrey2021/04/08 02:50 AM
                                            No conflict between theory and practiceAdrian2021/04/08 04:07 AM
                                            No conflict between theory and practiceanon22021/04/08 04:18 AM
                                              No conflict between theory and practiceAndrey2021/04/08 07:18 AM
                                                No conflict between theory and practiceanon22021/04/08 08:11 AM
                                                  No conflict between theory and practiceAndrey2021/04/08 08:48 AM
                                                    No conflict between theory and practiceanon22021/04/08 03:10 PM
                                            No conflict between theory and practice---2021/04/08 07:30 PM
                                              No conflict between theory and practicedmcq2021/04/09 01:25 AM
                                                No conflict between theory and practiceLinus Torvalds2021/04/09 08:44 AM
                                        No conflict between theory and practiceanon22021/04/08 03:09 AM
                                          No conflict between theory and practicesr2021/04/10 12:22 AM
                                            No conflict between theory and practiceAnon2021/04/10 03:00 AM
                                              No conflict between theory and practiceEtienne Lorrain2021/04/11 11:56 PM
                                                No conflict between theory and practiceAnon2021/04/12 12:54 AM
                                                  No conflict between theory and practicedmcq2021/04/12 12:44 PM
                              No conflict between theory and practiceGabriele Svelto2021/04/08 12:03 AM
                                No conflict between theory and practicedmcq2021/04/12 12:53 PM
                                  No conflict between theory and practicedmcq2021/04/14 03:50 AM
                      transactional memory = memory lock/unlocksr2021/04/09 11:56 PM
                        transactional memory = memory lock/unlockAnon2021/04/10 03:05 AM
                    No conflict between theory and practiceanon22021/04/07 04:19 PM
                No conflict between theory and practicedmcq2021/04/07 12:16 PM
            No conflict between theory and practiceAnon2021/04/06 09:46 AM
            No conflict between theory and practiceAspect of Anonimity2021/04/06 01:16 PM
              No conflict between theory and practiceNoSpammer2021/04/09 11:02 PM
                No conflict between theory and practicesr2021/04/10 12:47 AM
                No conflict between theory and practiceAspect of Anonimity2021/04/10 10:30 PM
                  No conflict between theory and practiceAndrey2021/04/11 04:05 AM
                    HmAspect of Anonimity2021/04/12 06:29 PM
                      Special internal SRAM to store Mutex?Etienne Lorrain2021/04/13 12:01 AM
                        Special internal SRAM to store Mutex?Anon2021/04/13 12:26 AM
                        Special internal SRAM to store Mutex?Linus Torvalds2021/04/13 08:53 AM
                        Special internal SRAM to store Mutex?Dan Fay2021/04/13 11:03 AM
                          Special internal SRAM to store Mutex?Ben LaHaise2021/04/13 02:32 PM
                          Special internal SRAM to store Mutex?Gabriele Svelto2021/04/13 10:43 PM
                        Special internal SRAM to store Mutex?Carson2021/04/13 09:19 PM
          No conflict between theory and practicesr2021/04/06 06:12 AM
            No conflict between theory and practiceAnon2021/04/06 09:43 AM
            No conflict between theory and practiceAspect of Anonimity2021/04/06 02:20 PM
              No conflict between theory and practicesr2021/04/07 09:09 AM
                No conflict between theory and practiceanon22021/04/07 07:53 PM
  Armv9 officially announceddmcq2021/03/30 02:28 PM
    Totally backwads logic on compatibilityHeikki Kultala2021/03/30 02:44 PM
      Totally backwads logic on compatibilityDoug S2021/03/31 11:09 AM
        Totally backwads logic on compatibilitydmcq2021/03/31 02:15 PM
  Armv9 officially announcedv92021/04/12 02:57 PM
    Armv9 officially announcedj2021/04/13 04:07 AM
      Armv9 officially announcedDoug S2021/04/13 09:21 AM
        Armv9 officially announcedanonymou52021/04/13 10:06 AM
          Armv9 officially announcedDoug S2021/04/13 12:01 PM
        Armv9 officially announceddmcq2021/04/13 02:20 PM
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