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    SubjectRe: [PATCH v10]: Hibernation: fix the number of pages used for hibernate/thaw buffering
    2012-04-12 23:30, Bojan Smojver skrev:
    > I was thinking more like this:
    > ----------------------
    > unsigned long read_pages = 0;
    >
    > [...]
    >
    > if (low_free_pages() > snapshot_get_image_size())
    > read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
    > read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES);
    > ----------------------
    >
    > Where LZO_MIN_RD_PAGES and LZO_MAX_RD_PAGES are set to 1024 and 8192,
    > respectively (this was picked empirically).
    >
    > Because we don't really know how many highmem pages are in the image
    > (this is figured out by prepare_image() function, half way through
    > reading the image - so way after this calculation is done), we assume
    > the worst case scenario. And that is that there are no highmem pages in
    > the image.
    >
    > Given that we cannot use pages from highmem for buffers anyway, the
    > above should be careful enough. Of course, there is still some
    > possibility of running out of pages, but the kernel is usually in a
    > pretty good shape memory-wise on image load, so we should be able to
    > squeeze a few MBs out of it, at least.

    OK, I see your point now.

    Yet another reason to switch to 64-bit then I guess :-)

    --
    Pelle


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