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    SubjectRe: [patch 5/6] mm: simplify vmscan vs release refcounting
    On Thu, Jan 19, 2006 at 11:35:29AM -0800, Linus Torvalds wrote:
    > On Thu, 19 Jan 2006, Nick Piggin wrote:
    > >
    > > The VM has an interesting race where a page refcount can drop to zero, but
    > > it is still on the LRU lists for a short time. This was solved by testing
    > > a 0->1 refcount transition when picking up pages from the LRU, and dropping
    > > the refcount in that case.
    > Heh. Now you keep the count offset, but you also end up removing all the
    > comments about it (still) being -1 for free.
    > And your changelog talks about "atomic_inc_not_zero()" even though the
    > code actually does
    > atomic_add_unless(&page->_count, 1, -1);
    > which makes it pretty confusing ;)
    > I also think it's wrong - you've changed put_page_testzero() to use
    > "atomic_dec_and_test()", even though the count is based on -1.
    > So this patch _only_ works together with the next one, and is invalid in
    > many ways on its own. You should re-split the de-skew part correctly..

    Man I'm really happy one of us is awake. Sorry, I'll resend the last two.

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      Last update: 2006-01-19 20:55    [W:0.025 / U:4.044 seconds]
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