Kernel Fun

This weekend I decided to upgrade from my trusty 2.4.16 + preempt to something a bit more recent. The first thing I tried was 2.4.18-pre3 + O(1) + preempt + lock-break, which fell over miserably on my system (eg if it didn't panic at boot I could consistently cause a panic with a gmake -j5). After some "testing" on IRC with Robert Love (ie, boot, wait until panic and hard lock, write entire panic on piece of paper, reboot into stable kernel and type up panic, post panic to web for Robert to run ksymoops on, apply patch to kernel, reboot, repeat), I finally decided to take a break from preempt for the week and give low latency a shot. I'm running 2.4.17 + rmap + O(1) + low latency now, and it seems to be pretty stable. I'll try out preempt + lock-break again this weekend and let everyone know what happens. By the way, the problems I mentioned above with preempt have to do with SMP and preemption near interrupts -- all you single-processor users have nothing to fear.

There has been a really amusing thread on the LKML for the last few weeks regarding automatic kernel build configuration. The thread started as a question from ESR about probing the ISA bus, and progressed (devolved?) into an amusing war of metaphors between Alan Cox and ESR. Essentially, ESR used a hypothetical "Aunt Tillie" to represtent the typical technology-impaired "mom and pop" Linux user, who, for some unspecified reason, opts to compile her own kernel instead of using the modular vendor-supplied, vendor-tested, and vendor-supported version. After the Aunt Tillie scenario made relatively little progress against Alan Cox and a handful of other people, ESR added "Nephew Melvin" to the list of hypothetical characters. Anyway, Alan Cox's latest contribution to the argument:

From: Alan Cox <>
pabs@gw-uunet:~> whois
  Melvin?  What do I type here?
  10 Alan Turing Road
  Surrey Research Park
  Guildford, Surrey GU2 7YF

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