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Not the Gentoo Weekly Newsletter, Part 5

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Learning buzzwords: Turing-complete

There are times when you need some big words to impress people. Proactively embiggen your reputation, leveraging intellectual stimuli to cause synergetic paradigm shifts. That kind of big words. So here's a good one for all discussions about computer programming and programming languages:

Turing-complete

But we need to give you some context so you know when to use it and when it's not appropriate. So let's start with Turing. That's just the family name of Alan Turing, a british mathematician who committed suicide because he was gay and the secret service was unable to employ such perverted people (what a dark age that was ...). He was also involved in code cracking in the second World War and one of the early pioneers of digital computing. But because he was a maths guy he tried to model computers abstracly so he could deduce what they can effectively compute.

So as a thought experiment he abstracted a computing device to be a tape to store things, a read/write head that can move along the tape and some internal state of the machinery that decides what to do next. So for example the abstract turing machine would read a "1" from the tape, look in its state and then decide to write a "0" there and move one field to the left. Keep in mind that no such machine really exists, it's just a mental model for discussing computability. Also you may notice an interesting abstraction: Wether the machine reads a "1" or a "red flower" symbol is equivalent. Numbers are symbols, and symbols are numbers. Mmmmh ...

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More in Tux Machines

Amazon Linux 2 - Who nicked my cheese?

So far, it's a relatively benign, easy introduction to a new operating system that blends the familiar and new in a timid package. Perhaps that's the goal, because a radical offering would right away scare everyone. Amazon Linux 2 is an appealing concept, as it gives users what Red Hat never quite did (yet) - A Fedora-like bleeding-edge tech with the stability and long-term support of the mainstay enterprise offering. But then, it also pulls a Debian/Ubuntu stunt by breaking ABI, so it will be cubicle to those who enjoying living la vida loco (in their cubicle or open-space prison). Having lived and breathed the large-scale HPC world for many years, I am quite piqued to see how this will evolve. Performance, stability and ease of use will be my primary concerns. Then, is it possible to hook up a remote virtual machine into the EC2 hive? That's another experiment, and I'd like to see if scaling and deployment works well over distributed networks. Either way, even if nothing comes out of it, Amazon Linux 2 is a nice start to a possibly great adventure. Or yet another offspring in the fragmented family we call Linux. Time will tell. Off you go. Cloud away. Read more

Updates From OpenIndiana and LibreOffice (Projects That Oracle Discarded)

  • Migration to GCC 6.4 as userland compiler
    Modulo some minor details, the transition of our userland to GCC 6 is complete.
  • OpenIndiana Has Upgraded To The GCC 6 Compiler
    The OpenSolaris/Illumos-based OpenIndiana operating system has finally moved past GCC 4.9 as its base user-land compiler and is now using GCC 6.4. This comes while GCC 8.1 should be officially released in the next few weeks and they are already targeting GCC 7.3.0 as their next illumos-gate compiler.
  • LibreOffice 6.0 Open-Source Office Suite Passes 1 Million Downloads Mark
    The Document Foundation announced recently that its LibreOffice 6.0 open-source and cross-platform office suite reached almost 1 million downloads since its release last month on January 31, 2018. That's terrific news for the Open Source and Free Software community and a major milestone for the acclaimed LibreOffice office suite, which tries to be a free alternative to proprietary solutions like Microsoft Office. The 1 million downloads mark was reached just two weeks after the release of LibreOffice 6.0, which is the biggest update ever of the open-source office suite adding numerous new features and enhancements over previous versions.

FreeBSD Finally Gets Mitigated For Spectre & Meltdown (and Hugs)

  • FreeBSD Finally Gets Mitigated For Spectre & Meltdown
    Landing in FreeBSD today was the mitigation work for the Meltdown and Spectre CPU vulnerabilities. It's taken a few more weeks longer than most of the Linux distributions to be re-worked for Spectre/Meltdown mitigation as well as DragonFlyBSD, but with FreeBSD Revision 329462 it appears their initial fixes are in place. There is Meltdown mitigation for Intel CPUs via a KPTI implementation similar to Linux, the Kernel Page Table Isolation. There is also a PCID (Process Context Identifier) optimization for Intel Westmere CPUs and newer, just as was also done on Linux.
  • FreeBSD outlaws virtual hugs
  • AsiaBSDCon 2018 Conference Programme

Linux: To recurse or not

Linux and recursion are on very good speaking terms. In fact, a number of Linux command recurse without ever being asked while others have to be coaxed with just the right option. When is recursion most helpful and how can you use it to make your tasks easier? Let’s run through some useful examples and see. Read more