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    SubjectRe: [PATCH] skip initramfs check
    On Monday 21 November 2005 00:23, Marcelo Tosatti wrote:
    > Hi Rob,
    > > Query: is the problem that a big initramfs image is being unpacked more
    > > than once, or is unpacking an empty initramfs image (134 bytes) causing a
    > > significant delay?
    > The problem is a big non-initramfs RAMDISK image (used for root mountpoint
    > on this particular embedded platform), that is decompressed more than once:
    > - during the initramfs check, which fails because it is not initramfs.
    > - during the real RAMDISK decompression to memory.
    > > I'm fairly certain that back in 1990 I could unzip 134 bytes on my 33 mhz
    > > 386 running dos in a fraction of a second. What's the use case here?
    > So the issue is not the empty initramfs image (which BTW could probably
    > be made unecessary?), but a 10Mb RAMDISK image being decompressed by a
    > 48Mhz PPC, which takes quite a few seconds.
    > Need to rework the patch to use a __setup option as Andrew suggested.

    It sounds to me like is the initial check (which is just giving a thumbs
    up/thumbs down "is this an initramfs", correct?) only needs to decompress the
    first page or so of data to make this determination. A quick glance at the
    code seems to imply it's just checking the header and the first entry, so 4k
    should be plenty for that.

    Some variant of lib/zlib_inflate... Ouch, bit of a mess there. Hey Matt: you
    know this area. Is it feasible to do some kind of:

    deflate_next_x_bytes(source *, dest *, length)

    To grab a the first X bytes from the initramfs image?

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      Last update: 2005-11-21 16:08    [W:0.021 / U:13.696 seconds]
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