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[20100131] Unfilling my inbox: NetBSD news from the past few weeks - ACPI, NUMA, Xen, and more
Herre are some more things that I've caught in my inbox for too long, and I'm finally finding some time to sum them up here:
  • NetBSD's "let's move kernel parts to the userland" RUMP project is still under heavy development, and in order to make testing of compatibility after kernel changes easier, a new command "rumptest" was added to build.sh: ``Basically you say:
    	    ./build.sh ${yourargs} tools ; ./build.sh ${yourargs} rumptest
    	
    Where yourargs are what have you, e.g. '-U -u -o -O /objs'.

    The latter builds only the rump kernel libs and uses some ld+awk magic to figure out if things go right or not. This is to avoid having to install headers and build libs (which is too slow since a full build is too slow). The magic is not a substitute for a full build, but it is n+1 times faster and works probably 99.9% of the time.

    The scheme uses a number of predefined component sets (e.g. tmpfs+vfs+rumpkern) to test linkage. They are currently listed in build.sh. This area probably needs some work in the future. It would be nice to autogenerate the combinations somehow.

    If things go well, you get something like this:

            ===> Rump build&link tests successful
            ===> build.sh ended:   Wed Nov 18 20:10:59 EET 2009 
    '' See Antti's Antti's mail to tech-kern: on how to tell if things didn't go so well, and what to do in that case.

  • According to Wikipedia, ``Non-Uniform Memory Access or Non-Uniform Memory Architecture (NUMA) is a computer memory design used in multiprocessors, where the memory access time depends on the memory location relative to a processor. Under NUMA, a processor can access its own local memory faster than non-local memory, that is, memory local to another processor or memory shared between processors.''

    Supporting NUMA in a contemporary (i.e.: Intel centric) SMP-enabled operating system requires following a bunch of standards, two of which are parsing of two tables, the System Resource Affinity Table (SRAT) and the System Locality Information Table (SLIT). Both tables are accessible via the Advanced Configuration and Power Interface (ACPI), and according to the German-language Wikipedia, the SRAT is used to assign local memory to local threads to boost their performance, and the SLIT defines the "distance" of the nodes among themselves, which is used to determine the "nearest" memory if local memory is not enough.

    Now, Christop Egger has posted patches to add an ACPI SLIT parser and an ACPI SRAT parser. See the two postings for dmesg pr0n from his tests on an 8-node system.

  • Staying with ACPI and Christoph Egger, he found that even though the ACPI spec defines an ACPI device for fans, BIOS vendors and OEMs do their own thing. To accommodate things like the fan sensor found in the ACPI Thermal Zone in his HP Pavillion DV9700 laptop he has proposed a driver to extend the acpitz(4) driver with fan information. That way, envstat(8) can be used to display the ran's RPMs:
    [acpitz0]
      Processor Thermal Zone:     56.000   95.000                       degC
                         fan:       2840                                 RPM 

  • Staying with driver games, iMil writes me that there's documentation on getting DRI, AIGLX, Composite and Compiz going with NetBSD 5.0 available in the O(ther)NetBSD Wiki now.

    The documentation covers how to enable the Direct Rendering Manager (DRI), setting up and configuring Modular X.org, assuring that everything's in place, and how to get Compitz going. Mmm, wobbly windows at last! :-)

  • While we're talking funky desktop stuff: Marc Balmer has submitted a patch to get touchpanel support for ums(4). ums(4) is for USB mice, and in contrast to mice, touch panels need to deal with absolute numbers, not relative numbers.

  • Back to the guts of the kernel, another patch suggested by Christop Egger was for adding x2apic. What is x2apic? X2APIC is ``an Intel-only feature but can also be found in virtual environments with support for CPU apic id's > 0xff.

    I.e. Xen 4.0 (not yet released) supports 128 CPUs in HVM guests with the CPUs enumerated with even apic id's. That means you need x2apic for the 128th CPU :) ''

  • While speaking of Xen: Xen 4.0 is coming soon, and there's a call to help testing it on NetBSD!

    Install Mercurial, check out latest Xen sources, apply a bunch of patches, build and install. Examples of commands are given, in addition to changes required for /boot.cfg etc.

    Report your findings to port-xen!

  • Last one for today: Michal Gladecki, Editor-in-Chief of BSD Magazine writes: ``We are happy to announce that BSD Magazine is transforming into a free monthly online publication. The online version of BSD Magazine will stay in the same quality and form. It will look like the BSD magazine one is familiar and comfortable with. Please sign up to our newsletter at www.bsdmag.org and get every issue straight to your inbox. Also, you can now download any of the previous issues from our website. The first online issue -- 2/2010 -- is coming out in February. Please spread the word about BSD Magazine. '' Click!

So much for today. I still have a bunch of news items in my inbox for next time, but let's call it good for today.

Unrelated, I've been playing with git a bit over the past few days, and wile I have a number of questions building up (which will be subject to tech-repository or so), what I can say today is that the speed of "git pull" with NetBSD's git repository and my 1MBit DSL line reminds me a lot of the times when I used SUP with my 56k modem - it took forever, too. :-(

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