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My main workstation is too a Raptor Power9 running Void since November 2019, and I’m very happy with it although as the article mentions, “My experience with fi

My main workstation is too a Raptor Power9 running Void since November 2019, and I’m very happy with it although as the article mentions, “My experience with firmware is that open source does not mean necessarily better, rather the opposite”. OpenBMC (the firmware for the little ARM-based embedded computer that boots the big one) has a number of rough edges. From time to time I submit patches to software to make it work (or work better) on this machine, last week it was these two trivial ones: https://github.com/ciao-lang/ciao/pull/45 https://github.com/ciao-lang/ciao/pull/45 https://github.com/janet-lang/janet/pull/915 https://github.com/janet-lang/janet/pull/915 Typically that’s all that’s needed, in some cases it’s just more of it: https://github.com/oneapi-src/oneDNN/pull/767 https://github.com/oneapi-src/oneDNN/pull/767 But for most things, since it’s Linux, it’s just those small changes: (one of my customers runs the software I write on AIX and that’s a little more work) https://github.com/IntelRealSense/librealsense/pull/5586 https://github.com/IntelRealSense/librealsense/pull/5586 https://sourceforge.net/p/speed-dreams/tickets/1022/ https://sourceforge.net/p/speed-dreams/tickets/1022/ For Rust programs, many packages used i8 for C strings (to interface with OpenGL for instance) which broke when running on ppc64 and had to be changed to c_char, but that’s not a problem these days, I guess because many people now test on ARM. https://github.com/femtovg/femtovg/pull/5 https://github.com/femtovg/femtovg/pull/5 Before Power10 was done, IBM actually asked us Raptor users about proposals for useful machine code instructions to add to it. I replied that I’d like to have hardware UTF-8 de-/encoding but they wanted a more detailed proposal and I never got around to write it. I’m not even sure that this would be worthwhile, but I see UTF-8 de-/encoding everywhere in the code I write and would like it to approach memory read/write speeds. I was very disappointed to learn that they had gone more proprietary with Power10 so I would not have been able to use those instructions anyway. What a pity! This machine still covers my needs so I’m not planning to replace it any time soon.

gnufx 5y ago
I don't manage the system I work on, so I don't see OpenBMC, but "a number of rough edges" sounds a lot better than the proprietary BMCs it's been my misfortune to use, which appear basically to be unsupported. As far as rust goes, I've just asked around for rust expertise to try to get a feel for whether it's worth persisting with trying to make the stuff work that a user wants, since I know nothing about it. (The first issue I found was exactly i8 in a current crate.) That is rather the exception in building free software for ppc64le, though, in my experience of packaging HPC-type stuff. The real problems are with Mellanox/NVIDIA proprietary stuff for GPU support.
classichasclass 5y ago
Interesting, never heard about them asking about ISA changes. Where was that done? There are some lovely new instructions in Power10 but until they get the firmware source out fully I won't use them in the Firefox JIT.
- AlbertoGP 5y ago
  It was through the IRC channel. I sent a direct message as response and exchanged a couple of sentences, then they gave me their IBM email address to submit the detailed proposal. My understanding was that it would have to be justified and for that I would have to show that it could be more efficient than an implementation based on the existing SIMD instructions which I’m not familiar with. I suspect that the kind of instructions that could actually be put there might not perform better than that. I regret not sending at least an amateurish proposal, I still think it would be a good idea to have no-cost UTF-8 en-/decoding. Not just for text, but for general variable-length encoding of other kinds of data.
  - classichasclass 5y ago
    Very interesting. Which channel specifically? VSX is really where the new development is happening, but it's become quite complete. The PC-direct instructions first made available in P9 also really closed a gap (beforehand you had to do bl with a weird flag to get PC in LR without trashing the history table).
    - AlbertoGP 5y ago
      The IRC channel was #talos-workstation on FreeNet, now on Libera.Chat. Do you know of some minimal example of calling VSX instructions from C? Ideally just one .c file and one Makefile or README with the exact GCC command to compile it, plus a pointer to documentation describing each instruction. I’ve seen assembler inserted into C source code with GCC, but I’ve never done it and I assume there are some non-obvious details to take into account.
      - 5y ago

gnufx 5y ago

I don't manage the system I work on, so I don't see OpenBMC, but "a number of rough edges" sounds a lot better than the proprietary BMCs it's been my misfortune to use, which appear basically to be unsupported. As far as rust goes, I've just asked around for rust expertise to try to get a feel for whether it's worth persisting with trying to make the stuff work that a user wants, since I know nothing about it. (The first issue I found was exactly i8 in a current crate.) That is rather the exception in building free software for ppc64le, though, in my experience of packaging HPC-type stuff. The real problems are with Mellanox/NVIDIA proprietary stuff for GPU support.

classichasclass 5y ago

Interesting, never heard about them asking about ISA changes. Where was that done? There are some lovely new instructions in Power10 but until they get the firmware source out fully I won't use them in the Firefox JIT.

AlbertoGP 5y ago
It was through the IRC channel. I sent a direct message as response and exchanged a couple of sentences, then they gave me their IBM email address to submit the detailed proposal. My understanding was that it would have to be justified and for that I would have to show that it could be more efficient than an implementation based on the existing SIMD instructions which I’m not familiar with. I suspect that the kind of instructions that could actually be put there might not perform better than that. I regret not sending at least an amateurish proposal, I still think it would be a good idea to have no-cost UTF-8 en-/decoding. Not just for text, but for general variable-length encoding of other kinds of data.
- classichasclass 5y ago
  Very interesting. Which channel specifically? VSX is really where the new development is happening, but it's become quite complete. The PC-direct instructions first made available in P9 also really closed a gap (beforehand you had to do bl with a weird flag to get PC in LR without trashing the history table).
  - AlbertoGP 5y ago
    The IRC channel was #talos-workstation on FreeNet, now on Libera.Chat. Do you know of some minimal example of calling VSX instructions from C? Ideally just one .c file and one Makefile or README with the exact GCC command to compile it, plus a pointer to documentation describing each instruction. I’ve seen assembler inserted into C source code with GCC, but I’ve never done it and I assume there are some non-obvious details to take into account.
    - 5y ago