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    SubjectRe: page fault scalability patch V11 [0/7]: overview
    William Lee Irwin III wrote:
    > William Lee Irwin III wrote:
    >
    >>>Unprivileged triggers for full-tasklist scans are NMI oops material.
    >
    >
    > On Sat, Nov 20, 2004 at 01:25:37PM +1100, Nick Piggin wrote:
    >
    >>What about pushing the per-thread rss delta back into the global atomic
    >>rss counter in each schedule()?
    >>Pros:
    >>This would take the task exiting problem into its stride as a matter of
    >>course.
    >>Single atomic read to get rss.
    >>Cons:
    >>would just be moving the atomic op somewhere else if we don't get
    >>many page faults per schedule.
    >>Not really nice dependancies.
    >>Assumes schedule (not context switch) must occur somewhat regularly.
    >>At present this is not true for SCHED_FIFO tasks.
    >>Too nasty?
    >
    >
    > This doesn't sound too hot. There's enough accounting that can't be
    > done anywhere but schedule(), and this can be done elsewhere. Plus,
    > you're moving an already too-frequent operation to a more frequent
    > callsite.
    >

    No, it won't somehow increase the number of atomic rss operations
    just because schedule is called more often. The number of ops will
    be at _most_ the number of page faults.

    But I agree with your overall evaluation of its 'hotness'. Just
    another idea. Give this monkey another thousand years at the keys
    and he'll come up with the perfect solution :P
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