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Tuning The Kernel With A Genetic Algorithm

Posted by michael on from the self-modifying-code dept.

fsck! writes "Jake Moilanen provided a series of four patches against the 2.6.9 Linux kernel that introduce a simple genetic algorithm used for automatic tuning. The patches update the anticipatory IO scheduler and the zaphod CPU scheduler to both use the new in-kernel library, theoretically allowing them to automatically tune themselves for the best possible performance for any given workload. Jake says, 'using these patches, there are small gains (1-3%) in Unixbench & SpecJBB. I am hoping a scheduler guru will able to rework them to give higher gains.'"

3 of 251 comments (clear)

  1. Complexity? by BurntNickel · · Score: 5, Insightful

    So how much additional complexity is added for a 1-3% perfomance improvement? I'm all for more speed, but keeping thinks simple can often be more improtant when it comes to maintainablity and adding additional features.

    --
    And the knowledge that they fear is a weapon to be used against them...
  2. Re:Not worth it... by Corfe · · Score: 5, Insightful

    It's a unique idea - what's wrong with running it for a while with your typical load (say, for a fileserver), finding some better-than-average parameters for the kernel, then running an unpatched kernel with those parameters manually entered?

    What is "on the borders of statistical error" depends on how many times the test was run, and how much variation there had been in his results before. I think it's pretty safe to assume that if he knows how to implement a genetic algorithm into the linux kernel, he knows how to handle statistics properly.

  3. GAs aren't rocket science by Earlybird · · Score: 5, Insightful
    Because most people aren't intimately familiar with genetic algorithms, and because GAs are associated with machine learning/artificial intelligence, GAs are seen as somewhat mysterious and magical, and are therefore either accepted with "whoa, cool!" or rejected with "whoa, complex!" While GAs are indeed novel compared to many long-established algorithms, both mentalities are overreactions.

    In reality, the basic GA framework is "just" another efficient search algorithm, no cooler or more complex than, say, a hash table or a binary search tree; at its simplest, a GA is a way to find an optimal configuration of components without looking at all possible (potentially explosively exponential) combinations; instead, you look at just some permutations, and as you iterate through generations, applying breeding and mutation, you arrive at a generation which is statistically close to optimal.

    GAs are also in no way new or unproven technology; a nice example of mainstream use is PostgreSQL's query planner, which uses GAs to optimize query plans.