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    SubjectRe: schedule() && prev/current (Was: [PATCH 3/3] Make get_current() __attribute__((const)))
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    On Tue, 2010-05-18 at 23:22 +0200, Oleg Nesterov wrote:

    > And, looking at this patch I think that schedule() can be simplified
    > a little bit.
    >
    > "sched: Reassign prev and switch_count when reacquire_kernel_lock() fail"
    > commit 6d558c3ac9b6508d26fd5cadccce51fc9d726b1c says:
    >
    > Assume A->B schedule is processing,
    > ...
    > Then on B's context,
    > ...
    > prev and switch_count are related to A
    >
    > How so? switch_count - yes, we should change it. But prev must be
    > equal to B, and it must be equal to current. When we return from
    > switch_to() registers/stack should be restored correctly, so we
    > can do

    What if schedule() got called at a different stack depth than we are
    now?

    I don't think we can assume anything about the stack context we just
    switched to.


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