GNU/Linux S5R3 App 4.49 available for Beta test

Forums › Cruncher's Corner

Bernd Machenschalk
Bernd Machenschalk
Joined: 15 Oct 04
Posts: 2,684
Credit: 25,950,161
RAC: 34,820
14 May 2008 12:39:26 UTC
Topic 13670
(moderation:
    )

    A new Linux App is available from our Beta Test page.

    This is a "switching" App as you already know from the 4.38 App.

    If something goes wrong with the automatic switching (i.e. you get "signal 4" "illegal instruction" errors), placing a file named "CPU_TYPE_0" in the BOINC directory should run the generic (non-SSE) App even if the wrapper would detect SSE.

    The SSE App was built with compiler settings that should use the SSE unit for most arithmetics (-mfpmath=sse). There might be a difference in speed overall in one or the other direction, but mainly it should serve two purposes: first we try to avoid the FPU exceptions by avoid using the FPU, and second it should improve the prefetching of the Hough code (actually enable parts of it). This means that the App should run faster and further reduce the variance in run-times between workunits compared to previous versions.

    In addition the App was built with BOINC API as of May 7, which means that it should work properly with latest development clients.

    The app_info.xml has entries for

    420
    421
    424
    427
    431
    435
    438
    449

    If your current App version is not listed here, you'll have to add it manually.

    BM

    BM

    Bernd Machenschalk
    Bernd Machenschalk
    Joined: 15 Oct 04
    Posts: 2,684
    Credit: 25,950,161
    RAC: 34,820

    GNU/Linux S5R3 App 4.49 available for Beta test

    14 May 2008 15:07:37 UTC
    Message 3528
    (moderation:
      )

      Quote:

      My AMD X2 5000 swiched fine, but my AMD XP 3000 wrecked all WUs.

      From stderr.txt:

      393, 394, 395, 396, 397, 398, 399, 400, 401, 402, 403, 404, 405, 406, 407, 408, Detected CPU type 1
      SIGILL: illegal instruction
      Stack trace (5 frames):
      ../../projects/einstein.phys.uwm.edu/einstein_S5R3_4.49_i686-pc-linux-gnu_1[0x81946a1]
      [0xffffe420]
      ../../projects/einstein.phys.uwm.edu/einstein_S5R3_4.49_i686-pc-linux-gnu_1[0x806b368]
      /lib/libc.so.6(__libc_start_main+0xe0)[0xb7d8dfe0]
      ../../projects/einstein.phys.uwm.edu/einstein_S5R3_4.49_i686-pc-linux-gnu_1(shmat+0x55)[0x804b5c1]

      Exiting...

      cu,
      Michael

      Too bad. Are there SSE2 instructions in the executable?

      Does the CPU_TYPE_0 work for the moment?

      BM

      BM

      Bernd Machenschalk
      Bernd Machenschalk
      Joined: 15 Oct 04
      Posts: 2,684
      Credit: 25,950,161
      RAC: 34,820

      It indeed did contain SSE2

      14 May 2008 16:10:10 UTC
      Message 3529
      (moderation:
        )

        It indeed did contain SSE2 instructions. I built a new SSE App and updated the archive (and the md5sum on the page).

        Thanks for the report.

        BM

        BM

        Bernd Machenschalk
        Bernd Machenschalk
        Joined: 15 Oct 04
        Posts: 2,684
        Credit: 25,950,161
        RAC: 34,820

        RE: 1. Is it possible, that

        14 May 2008 17:52:38 UTC
        Message 3530
        (moderation:
          )

          Quote:
          1. Is it possible, that the first version(with some SSE2 instructions) might be faster than the new one?


          Yes, it is possible, but I simply don't know.

          That reminds me that I wanted to post some "reference workunit" for direct speed comparison. Will pick this up soon.

          Quote:
          2. Does the new beta app have any advantages for non SSE CPUs?


          Not in speed. I still want to test the new BOINC API version, though, that's in both Apps, in particular with the latest Core Clients.

          BM

          BM

          Bernd Machenschalk
          Bernd Machenschalk
          Joined: 15 Oct 04
          Posts: 2,684
          Credit: 25,950,161
          RAC: 34,820

          RE: RE: Switched from

          15 May 2008 8:07:57 UTC
          Message 3531
          (moderation:
            )

            Quote:
            Quote:
            Switched from 4.35 to 4.49 on my AMD Opteron 1210 cpu running SuSE Linux 10.3 and BOINC 5.10.45. Looks definitely faster but graphics is not working. It used to work in 4.35.
            Tullio

            Graphics did not work when I switched from 4,35 to 4.49 during a WU run. Now that I started one with 4.49 it works,


            Yep. Switching App versions in the middle of a Task is not supported in BOINC. In case of the "separate graphics" Apps this means that the "graphics_app" link in the slot directory is not updated and points to a file that doesn't exist anymore after installing a new App version. It is only set up new when a new Task is started.

            BM

            BM

            Bernd Machenschalk
            Bernd Machenschalk
            Joined: 15 Oct 04
            Posts: 2,684
            Credit: 25,950,161
            RAC: 34,820

            RE: RE: RE: 1. Is it

            15 May 2008 8:54:45 UTC
            Message 3532
            (moderation:
              )

              Quote:
              Quote:
              Quote:
              1. Is it possible, that the first version(with some SSE2 instructions) might be faster than the new one?

              Yes, it is possible, but I simply don't know.

              Hey Bernd,

              How about you make that SSE2 version available as a "power user" app so that those of us who weren't quick enough of the mark can at least test it a little?

              That'll save us having to bribe Michael or th3 who are the two who have so far admitted to having it :-).


              For now I put a copy of the SSE2 App executable in http://einstein.phys.uwm.edu/power_apps/einstein_S5R3_4.49_1_i686-pc-linux-gnu.gz. This isn't a full-featured App package, you'll have to replace the file "einstein_S5R3_4.49_i686-pc-linux-gnu_1" in the 4.49 Beta Test App package with that (expanded) file.

              BM

              BM

              Bernd Machenschalk
              Bernd Machenschalk
              Joined: 15 Oct 04
              Posts: 2,684
              Credit: 25,950,161
              RAC: 34,820

              RE: RE: Hi all! I would

              15 May 2008 9:13:46 UTC
              Message 3533
              (moderation:
                )

                Quote:
                Quote:

                Hi all!

                I would be surprised to see a significant (if at all measurable) speedup for the initial app version that contains SSE2 instructions.

                The app code consists of parts are really important to performance, and those have now been converted to hand-optimized assembly code (SSE).

                The rest of the code is in C but not that crucial for performance. Only in those parts of the code there will be a difference in the two app versions, mostly by scalar double precision code being compiled to x87 or SSE2 instructions, respectively. To make optimal use of SSE2, one would have to generate SSE2 versions of the handcoded sections.

                So, Iwould not hold my breath wrt. the SSE2 app variant.

                CU
                Bikeman


                In Bernd's initial posting I do not read anything about hand-coded SSE instructions, but about using a compiler switch.

                I do not doubt what you are writing, but this app clearly is at least 10% faster, so there might be a chance that the SSE2 version is even a little faster.

                Anyway, it will be fun to prove you are right. ;-)
                Or in other words: Let's see if practice can prove theory. :-)

                cu,
                Michael


                The overall speedup in the App compared to 4.38 mainly comes from prefetch compiler intrinsics placed in the Hough code that require these switches. Another bit of speedup arises from changes in the Assembler-coded "Kernel loop" (the "interleaving" of SSE and FPU commands we have in the 4.42 MacOS Intel App), but I think that this effect will be larger on modern Intel CPUs (Core2) than on AMDs.

                My guess is that the SSE2 App will be slightly faster if you would measure it against the SSE one, but you'll only notice the difference if you'd run the same workunit side by side e.g. on a dual core machine. It shouldn't be worth another case distinction in a "switching App".

                BM

                BM

                Bernd Machenschalk
                Bernd Machenschalk
                Joined: 15 Oct 04
                Posts: 2,684
                Credit: 25,950,161
                RAC: 34,820

                RE: RE: For now I put a

                16 May 2008 9:16:24 UTC
                Message 3534
                (moderation:
                  )

                  Quote:
                  Quote:
                  For now I put a copy of the SSE2 App executable in http://einstein.phys.uwm.edu/power_apps/einstein_S5R3_4.49_1_i686-pc-linux-gnu.gz.

                  Thanks for doing that.

                  One other point I'd like to mention. The instructions on the beta test page talk about adding the "five files" from the package ... Now I imagine the first version of the archive probably did contain five files but the current "fixed" version now contains seven files. Are these seven files all necessary?


                  Nope. I fixed the archive.

                  BM

                  BM

                  Bernd Machenschalk
                  Bernd Machenschalk
                  Joined: 15 Oct 04
                  Posts: 2,684
                  Credit: 25,950,161
                  RAC: 34,820

                  RE: For now I put a copy of

                  16 May 2008 9:20:33 UTC
                  Message 3535 in response to message 3532
                  (moderation:
                    )

                    Quote:
                    For now I put a copy of the SSE2 App executable in http://einstein.phys.uwm.edu/power_apps/einstein_S5R3_4.49_1_i686-pc-linux-gnu.gz. This isn't a full-featured App package, you'll have to replace the file "einstein_S5R3_4.49_i686-pc-linux-gnu_1" in the 4.49 Beta Test App package with that (expanded) file.


                    Yes, depending on the unpacking procedure this usually requires renaming the file.

                    BM

                    BM

                    Bernd Machenschalk
                    Bernd Machenschalk
                    Joined: 15 Oct 04
                    Posts: 2,684
                    Credit: 25,950,161
                    RAC: 34,820

                    RE: Great stuff,

                    16 May 2008 9:30:25 UTC
                    Message 3536
                    (moderation:
                      )

                      Quote:
                      Great stuff, Bernd.


                      Thanks, but most kudos should go to Bikeman and Akos for their great work!

                      BM

                      BM

                      Bernd Machenschalk
                      Bernd Machenschalk
                      Joined: 15 Oct 04
                      Posts: 2,684
                      Credit: 25,950,161
                      RAC: 34,820

                      RE: I just installed the

                      19 May 2008 12:17:12 UTC
                      Message 3537
                      (moderation:
                        )

                        Quote:

                        I just installed the beta app (not the SSE2 version yet) on my Fedora 7 -32 bit host.

                        The result that was in progress picked up fine and is crunching away.

                        The one that just downloaded and that is branded with 4.49 has an estimated time to completion of 40:26:20. It should take about 9.

                        DCF (as grabbed from client_state.xml) is 0.922172

                        Oh wise people, what did I do wrong?


                        Switching Apps in the middle of a task usually confuses the run-time estimation, but I don't precisely know why.

                        BM

                        BM

                        Comment viewing options

                        Select your preferred way to display the comments and click "Save settings" to activate your changes.

                        Forums › Cruncher's Corner