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    SubjectRe: [patch-2.3.40-pre6] kzalloc() (ala kmem_zalloc() of SVR4)
    Horst von Brand wrote:
    > > zeroing pages during system idle
    > > time, and then handing those out from kzalloc() (or
    > > kmalloc(GFP_ZERO|GFP_xxx) or whatever)
    >
    > What pages would you clear? Linux uses every bit of memory it gets its
    > hands on, and pages that are written out stay around in case their contents
    > are needed later. So I see very little oportunity for scavenging pages for
    > zeroing (perhaps just stuff that went to closed/unmounted filesystems).

    You'd do it anyway at the expense of other pages, if it improves
    performance... The reason it might improve performance is that you do
    the zero-fill in otherwise idle time. So you get getter overlap with
    I/O. In theory.

    And on a multiprocessor system one idle processor can zero pages while
    the other is consuming them.

    For similar reasons it might be worth pre-copying COW pages. I don't
    know if that's at all plausible. It's a pretty similar thing to
    pre-emptive swap-in.

    Perhaps you'd do the freepages.min pages -- pre-zeroed pages are quickly
    reclaimable after all.

    -- Jamie

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