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    SubjectRe: [PATCH 1/2] sched: Add schedule_(raw_)spin_unlock and schedule_(raw_)spin_unlock_irq
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    18.06.2013, 21:28, "Peter Zijlstra" <peterz@infradead.org>:
    > On Tue, Jun 18, 2013 at 07:36:52PM +0400, Kirill Tkhai wrote:
    >
    >>  Helpers for replacement repeating patterns:
    >>
    >>  1)spin_unlock(lock);
    >>    schedule();
    >>  2)spin_unlock_irq(lock);
    >>    schedule();
    >
    > I just noticed this; the existing schedule_preempt_disabled() is
    > equivalent to:
    >
    >   preempt_enable()
    >   schedule()
    >   preempt_disable()
    >
    > So I somewhat expected these new primitives to be:
    >
    >   spin_unlock()
    >   schedule()
    >   spin_lock()
    >
    > Now I haven't actually looked at the usage patch to see what the
    > converted sites look like (thanks for adding that one though!).
    >
    > My OCD just triggered on the preemption and locked schedule calls having
    > different semantics.

    They have different semantic and different ending.

    Many places (as you can see from the second patch) need additional actions
    between schedule() and next spin_lock(). Several places don't do the second
    lock.

    Kirill
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