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    SubjectRe: [RFC, PATCH] locks: remove posix deadlock detection
    On Sun, 28 Oct 2007, Matthew Wilcox wrote:

    > Bzzt. You get a false deadlock with multiple threads like so:
    > Thread A of task B takes lock 1
    > Thread C of task D takes lock 2
    > Thread C of task D blocks on lock 1
    > Thread E of task B blocks on lock 2

    A potential for deadlock occurs if a process controlling a locked
    region is put to sleep by attempting to lock another process'
    locked region. If the system detects that sleeping until a locked
    region is unlocked would cause a deadlock, fcntl() shall fail with
    an [EDEADLK] error.

    This is what POSIX says [1], even after being modified with respect to
    POSIX Threads Extension, right?

    So it doesn't deal with threads at all, just processess are taken into
    account. Probably for a reason :)

    [1] http://www.opengroup.org/onlinepubs/009695399/functions/fcntl.html

    --
    Jiri Kosina
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