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    SubjectRe: BUG: cpufreq notification broken
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    On Thu, 2006-11-16 at 15:27 -0500, Alan Stern wrote:
    > > Hmm, there are no static initializers for srcu and the only way to fix
    > > this up is to move the arch calls to postcore_init.
    >
    > If you can find a way to invoke init_cpufreq_transition_notifier_list
    > earlier than core_initcall time, that would be okay. I did it this way
    > because it was easiest, but earlier should be just as good.
    >
    > The only requirement is that alloc_percpu() has to be working, so that the
    > SRCU per-cpu data values can be set up. I don't know how early in the
    > boot process you can do per-cpu memory allocation.
    >
    > As an alternative approach, initialization of srcu_notifiers could be
    > broken up into two pieces, one of which could be done statically. The
    > part that has to be done dynamically (the SRCU initialization) wouldn't
    > mess up the notifier chain. Provided the dynamic part is carried out
    > while the system is still single-threaded, it would be safe.

    There is another issue with this SRCU change:

    The notification comes actually after the real change, which is bad. We
    try to make the TSC usable by backing it with pm_timer accross such
    states, but this behaviour breaks the safety code.

    tglx






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