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    SubjectRe: [PATCH] sound_core.c: Remove BKL from soundcore_open
    > it's getting time though to bite the bullet and make it a real normal
    > mutex. Lockdep will then flag a bunch of sh*t we'll need to fix, but
    > without doing that we're never going to really make progress.

    It won't. Instead you get situations like one ioctl blocking another to
    an unrelated device that just causes weird failures and performance
    problems, or in some cases deadlocks.

    Open routines block so it takes about 5 seconds of thought to realise
    that using a mutex here is brain dead and doesn't work.

    You push the BKL down. Next step from the call point is to replicate it
    inside each of the drivers that path can call, then in those drivers push
    the lock_kernel down and the internal locking up. Eventually they meet in
    the middle.

    If you try and do botch jobs with bogus mutex hacks it breaks, it breaks
    in ways lockdep doesn't understand and it doesn't even *help* fix the
    problem proper.


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      Last update: 2009-10-11 21:23    [W:0.019 / U:2.228 seconds]
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