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    SubjectRe: [PATCH 22/35] autonuma: sched_set_autonuma_need_balance
    On Tue, 2012-05-29 at 19:33 +0200, Andrea Arcangeli wrote:

    > No worries, I didn't mean to leave it like this forever. I was
    > considering using the stop cpu _nowait variant but I didn't have
    > enough time to realize if it would work for my case. I need to rethink
    > about that.

    No, you're not going to use any stop_cpu variant at all. Nothing is
    _that_ urgent. Your whole strict mode needs to go, it completely wrecks
    the regular balancer.

    > The moment I gave up on the _nowait variant before releasing is when I
    > couldn't understand what is tlb_migrate_finish doing, and why it's not
    > present in the _nowait version in fair.c. Can you explain me that?

    Its an optional tlb flush, I guess they didn't find the active_balance
    worth the effort -- it should be fairly rare anyway.

    > I'm glad you acknowledge load_balance already takes a bulk of the time
    > as it needs to find the busiest runqueue checking other CPU runqueues
    > too...

    I've never said otherwise, its always been about where you do it, in the
    middle of schedule() just isn't it. And I'm getting very tired of having
    to repeat myself.

    Also for regular load-balance only 2 cpus will ever scan all cpus, the
    rest will only scan smaller ranges. Your thing does n-1 nodes worth of
    cpus for every cpu.

     \ /
      Last update: 2012-05-30 00:41    [W:0.033 / U:11.376 seconds]
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