* a multicore XMOS CPU @ 2010-02-10 19:10 darek 2010-02-11 11:45 ` Ludovic Brenta ` (2 more replies) 0 siblings, 3 replies; 8+ messages in thread From: darek @ 2010-02-10 19:10 UTC (permalink / raw) Hi All, some time ago I have discovered very interesting CPU architecture developed at Bristol University (some of you still remember transputers) (http://www.xmos.com/). The CPU has 4 cores connected via an internal bus and every core can run up to 8 real-time threads per core (http://www.xmos.com/technology/silicon-technology). An internal clock @100MHz gives time resolution of 10ns. More about the architecture can be found here: http://www.xmos.com/support/documentation . Well, I could not resist and I got this evaluation board (https:// www.xmos.com/products/development-kits/xc-2-ethernet-kit). The company provides the whole set of development tools (https:// www.xmos.com/technology/design-tools) at no cost, and the tool chain is GNU based (there is also an extended C compiler that supports allocation of tasks at the core level). I am willing to dedicate some of my free time to try to port Ada compiler to this platform. Some thing, however, are not quite clear to my. For example: 1. How to distribute tasks between cores ? It is responsibility of the Ada run-time or the programmer shall do it explicitly (each core up to 8 real-time threads) via pragmas (I think, extending the language definition is not a good idea)? 2. Is it possible to create from publicly available source GNAT code a system that does not require any OS support (a bare metal solution)? 3. Last but not least. Is this enterprise worth any efforts (nice hobby project but then ...) ? I hope, that there would be some wise advices around .... Cheers, Darek P.S. Imagine an Ada program running on this device: https://www.xmos.com/products/development-kits/xmp-64 ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: a multicore XMOS CPU 2010-02-10 19:10 a multicore XMOS CPU darek @ 2010-02-11 11:45 ` Ludovic Brenta 2010-02-15 12:45 ` Colin Paul Gloster 2010-02-12 14:51 ` Lucretia 2010-02-15 13:10 ` Colin Paul Gloster 2 siblings, 1 reply; 8+ messages in thread From: Ludovic Brenta @ 2010-02-11 11:45 UTC (permalink / raw) darek <darek.maksim...@gmail.com> wrote on comp.lang.ada: > 1. How to distribute tasks between cores ? It is responsibility of > the Ada run-time or the programmer shall do it explicitly (each core > up to 8 real-time threads) via pragmas (I think, extending the > language definition is not a good idea)? I'd think the easiest, as a first step would be to mimic the extended C they provide and then, maybe, provide for dynamic thread allocation from within the kernel (see below). > 2. Is it possible to create from publicly available source GNAT code > a system that does not require any OS support (a bare metal solution)? Yes, it is possible. However I think tasking support requires a kernel such as the OpenRavenscar kernel[1]. [1] http://polaris.dit.upm.es/~ork/ > 3. Last but not least. Is this enterprise worth any efforts (nice > hobby project but then ...) ? I guess that's for you to decide. The experience you gain doing such a nice hobby project will be very valuable anyway. -- Ludovic Brenta. ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: a multicore XMOS CPU 2010-02-11 11:45 ` Ludovic Brenta @ 2010-02-15 12:45 ` Colin Paul Gloster 0 siblings, 0 replies; 8+ messages in thread From: Colin Paul Gloster @ 2010-02-15 12:45 UTC (permalink / raw) [-- Attachment #1: Type: TEXT/PLAIN, Size: 2528 bytes --] On Thu, 11 Feb 2010, Ludovic Brenta wrote: |------------------------------------------------------------------------| |"darek <darek.maksim...@gmail.com> wrote on comp.lang.ada: | |> 1. How to distribute tasks between cores ? It is responsibility of | |> the Ada run-time or the programmer shall do it explicitly (each core | |> up to 8 real-time threads) via pragmas (I think, extending the | |> language definition is not a good idea)?" | |------------------------------------------------------------------------| If you can accomplish a compiler which will automatically take up all of the cores, then congratulations. However, it is not unreasonable for the end users to be required to determine this scheduling. For example, I often need to run many programs and I have many cores for them. It often does not matter whether I run them all at onece, one per core, or one after the other, taking up many cores each time. It is trivial to efficiently put each on one core each. |------------------------------------------------------------------------| |"I'd think the easiest, as a first step would be to mimic the extended | |C they provide and then, maybe, provide for dynamic thread allocation | |from within the kernel (see below). | | | |> 2. Is it possible to create from publicly available source GNAT code | |> a system that does not require any OS support (a bare metal solution)?| | | |Yes, it is possible. However I think tasking support requires a kernel | |such as the OpenRavenscar kernel[1]. | | | |[1] http://polaris.dit.upm.es/~ork/ | | | |[..]" | |------------------------------------------------------------------------| Beware of ORK. It had a bug in it which had been fixed in GNAT seven years earlier. Not to mention the excessive overhead of ORK (as opposed to RAVENSCAR) for a virtually null program taking up nearly half of the memory you have (per core or overall, it was not clear from the product brief what the memory was being quoted for). ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: a multicore XMOS CPU 2010-02-10 19:10 a multicore XMOS CPU darek 2010-02-11 11:45 ` Ludovic Brenta @ 2010-02-12 14:51 ` Lucretia 2010-02-15 12:46 ` Colin Paul Gloster 2010-02-15 13:10 ` Colin Paul Gloster 2 siblings, 1 reply; 8+ messages in thread From: Lucretia @ 2010-02-12 14:51 UTC (permalink / raw) http://www.a-eon.com ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: a multicore XMOS CPU 2010-02-12 14:51 ` Lucretia @ 2010-02-15 12:46 ` Colin Paul Gloster 0 siblings, 0 replies; 8+ messages in thread From: Colin Paul Gloster @ 2010-02-15 12:46 UTC (permalink / raw) On Fri, 12 Feb 2010, Lucretia wrote: |----------------------| |"http://www.a-eon.com"| |----------------------| Luke, I found simply an uninformative webpage. Please elaborate. Thanks, Colin Paul Gloster ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: a multicore XMOS CPU 2010-02-10 19:10 a multicore XMOS CPU darek 2010-02-11 11:45 ` Ludovic Brenta 2010-02-12 14:51 ` Lucretia @ 2010-02-15 13:10 ` Colin Paul Gloster 2010-02-15 13:55 ` KarlNyberg 2 siblings, 1 reply; 8+ messages in thread From: Colin Paul Gloster @ 2010-02-15 13:10 UTC (permalink / raw) [-- Attachment #1: Type: TEXT/PLAIN, Size: 1613 bytes --] On Wed, 10 Feb 2010, Darek Maksimiuk sent: |------------------------------------------------------------------| |"[..] | | | |[..] | |I am willing to dedicate some of my free time to try to port Ada| |compiler to this platform. | |[..] | | | |[..] | | | |P.S. Imagine an Ada program running on this device: | |https://www.xmos.com/products/development-kits/xmp-64" | |------------------------------------------------------------------| Dear Darek Maksimiuk, Well, if you show me the C++ program which I showed in news:alpine.LNX.2.00.1002151055530.17315@Bluewhite64.example.net running on your XMOS development kit at a speed which when scaled up for an XMP-64 would be faster than an Intel quadcore machine, then I would be able to get an Ada compiler for it, if I could convince a funding agency to pay for an XMP-64. Please let me know what happens. Yours sincerely, Colin Paul Gloster, Grupo de Instrumentação Atómica e Nuclear, Departamento de Física, Universidade de Coimbra, Rua Larga, 3004-516 Coimbra, Portugal. Telephone: +351 239 410663 Fax: +351 239 829158 ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: a multicore XMOS CPU 2010-02-15 13:10 ` Colin Paul Gloster @ 2010-02-15 13:55 ` KarlNyberg 2010-02-15 15:31 ` Colin Paul Gloster 0 siblings, 1 reply; 8+ messages in thread From: KarlNyberg @ 2010-02-15 13:55 UTC (permalink / raw) On Feb 15, 8:10 am, Colin Paul Gloster <Colin_Paul_Glos...@ACM.org> wrote: > On Wed, 10 Feb 2010, Darek Maksimiuk sent: > > |------------------------------------------------------------------| > |"[..] | > | | > |[..] | > |I am willing to dedicate some of my free time to try to port Ada| > |compiler to this platform. | > |[..] | > | | > |[..] | > | | > |P.S. Imagine an Ada program running on this device: | > |https://www.xmos.com/products/development-kits/xmp-64" | > |------------------------------------------------------------------| > > Dear Darek Maksimiuk, > > Well, if you show me the C++ program which I showed innews:alpine.LNX.2.00.1002151055530.17315@Bluewhite64.example.net > running on your XMOS development kit at a speed which when scaled up > for an XMP-64 would be faster than an Intel quadcore machine, then I > would be able to get an Ada compiler for it, if I could convince a > funding agency to pay for an XMP-64. > > Please let me know what happens. > > Yours sincerely, > Colin Paul Gloster, > Grupo de Instrumentação Atómica e Nuclear, > Departamento de Física, > Universidade de Coimbra, > Rua Larga, > 3004-516 Coimbra, > Portugal. > Telephone: +351 239 410663 > Fax: +351 239 829158 That link didn't resolve to anything interesting for me. Can you forward me what you might have - it might be interesting to try it on my 8-core x 4 thread SunFire T1000. -- Karl -- ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: a multicore XMOS CPU 2010-02-15 13:55 ` KarlNyberg @ 2010-02-15 15:31 ` Colin Paul Gloster 0 siblings, 0 replies; 8+ messages in thread From: Colin Paul Gloster @ 2010-02-15 15:31 UTC (permalink / raw) [-- Attachment #1: Type: TEXT/PLAIN, Size: 7036 bytes --] [Note I use a news server which forbids attachments so the attachments mentioned below were emailed to Karl Nyberg.] On Mon, 15 Feb 2010, Karl Nyberg sent: |----------------------------------------------------------------------| |"On Feb 15, 8:10 am, Colin Paul Gloster <Colin_Paul_Glos...@ACM.org> | |wrote: | |> On Wed, 10 Feb 2010, Darek Maksimiuk sent: | |> | |> |------------------------------------------------------------------|| |> |"[..] || |> | || |> |[..] || |> |I am willing to dedicate some of my free time to try to port Ada|| |> |compiler to this platform. || |> |[..] || |> | || |> |[..] || |> | || |> |P.S. Imagine an Ada program running on this device: || |> |https://www.xmos.com/products/development-kits/xmp-64" || |> |------------------------------------------------------------------|| |> | |> Dear Darek Maksimiuk, | |> | |> Well, if you show me the C++ program which I showed in news:alpine.LNX.2.00.1002151055530.17315@Bluewhite64.example.net |> running on your XMOS development kit at a speed which when scaled up| |> for an XMP-64 would be faster than an Intel quadcore machine, then I| |> would be able to get an Ada compiler for it, if I could convince a | |> funding agency to pay for an XMP-64. | |> | |> Please let me know what happens. | |> | |> Yours sincerely, | |> Colin Paul Gloster, | |> Grupo de Instrumentação Atómica e Nuclear, | |> Departamento de Física, | |> Universidade de Coimbra, | |> Rua Larga, | |> 3004-516 Coimbra, | |> Portugal. | |> Telephone: +351 239 410663 | |> Fax: +351 239 829158 | | | |That link didn't resolve to anything interesting for me. Can you | |forward me what you might have - it might be interesting to try it on | |my 8-core x 4 thread SunFire T1000. | | | |-- Karl --" | |----------------------------------------------------------------------| Dear Mr. Nyberg, Please find attached in Logarithmic_Work_In_Ada.adb and logarithmic_work_in_CPlusPlus.cc and body_in_CPlusPlus.cc the timing programs which I presented in another thread on news:comp.lang.ada in the post news:alpine.LNX.2.00.1002151055530.17315@Bluewhite64.example.net They represent just a few per cent at most of real simulations which I work on such as in the attached files Cosima_activation_for_gamma_source__Step1.source and Gamma-Ray_Imager_includable_Cosima_commands_for_Steps_1_and_3.source and Gamma-Ray_Imager_includable_Cosima_commands_for_three_steps.source and geometry.geo.setup which are input files for MEGAlib (which can be downloaded from WWW.MPE.MPG.De/MEGA/megalib.html#downloads and which also needs you to download Geant and CLHEP (as explained in the MEGAlib installation manual)). Those *source and *setup files can be used (after you have installed MEGAlib) by copying them into a directory with about 800 megabytes free space and running date ; time cosima -s 1234 Cosima_activation_for_gamma_source__Step1.source >> Step1_with_seed_1234.stdout.txt 2>> Step1_with_seed_1234.stderr.txt ; date Note that the installation scripts supplied with MEGAlib and Geant and CLHEP do not use compiler optimization flags (not even when you use the scripts' options supposedly for optimization) so set these yourself or cosima would take more than twenty times longer to run if you compile with GCC. So, for compiling CLHEP, set the environment variable CXXFLAGS to a suitable value, for example in the case of GCC with BASH: export CXXFLAGS='-findirect-inlining -ftree-switch-conversion -O3 -ffast-math' If compiling on GNU/Linux with GCC then modifying the file geant4.9.2.b01/config/sys/Linux-g++.gmk to contain #Gloster wants optimization... CXXFLAGS += -O3 -findirect-inlining -ftree-switch-conversion -ffast-math #Gloster wants symbolic debugging... CXXFLAGS += -g would be a good idea. For Sun Studio on Solaris, it might be worthwhile checking whether geant4.9.2.b01/config/sys/SUN-CC.gmk lacks optimization flags. Similarly for MEGAlib, create the file MEGAlib/config/Makefile.user and in the case of GCC put something like #Gloster wants optimization... OPT += -O3 -findirect-inlining -ftree-switch-conversion -ffast-math #Gloster wants symbolic debugging... OPT += -g These libraries are not published in Ada, but I have made significant improvements in Ada which are not yet published. I would be interested in making a considerable amount of this work available to you in the near future. In the meantime I would be interested in timings which you could give me for Logarithmic_Work_In_Ada.adb and logarithmic_work_in_CPlusPlus.cc and Cosima_activation_for_gamma_source__Step1.source . I would be happy to collaborate with you on a paper. I have been tasked with considering whether it is worthwhile making a proposal to use a supercluster ( WWW.LCA.UC.Pt/welcome-to-milipeias-portal?set_language=en ). Perhaps your hardware could be used instead or also. Yours sincerely, Colin Paul Gloster P.S. Thank you for the annotated copy of the Ada83 standard which you gave me many years ago. Unfortunately it and other Ada hardcopy documents were damaged in a flood last month, but I have left it in sunlight and the worst of the damage seems to have cleared up quickly. ^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2010-02-15 15:31 UTC | newest] Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2010-02-10 19:10 a multicore XMOS CPU darek 2010-02-11 11:45 ` Ludovic Brenta 2010-02-15 12:45 ` Colin Paul Gloster 2010-02-12 14:51 ` Lucretia 2010-02-15 12:46 ` Colin Paul Gloster 2010-02-15 13:10 ` Colin Paul Gloster 2010-02-15 13:55 ` KarlNyberg 2010-02-15 15:31 ` Colin Paul Gloster
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