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    SubjectRe: [PATCH] BUG(): sched.c: Line 944

    On Tue, 17 Sep 2002, Ingo Molnar wrote:
    > this test is cheaper than a function call.

    Ehh.. On most architectures an unconditional direct function call is
    _faster_ than a conditional test that does not predict all that well. So
    the "test is faster than a function call" is not a very good optimization,
    I suspect.

    In fact, we'd probably be better off trying to factor out more out of
    schedule() rather than making it even bigger. We've done that before: the
    timeout stuff was done that way, and meant that normal reschedules no
    longer need to care about timeouts. That made things simpler.

    On the other hand, we do have other ways to test the preempt count inside
    the scheduler. In particular, we might just move the "in_atomic()" check a
    few lines downwards, at which point we've released the kernel lock and
    explicitly disabled preemption, so at that point the test should be even
    simpler with fewer conditionals..


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