Re: subobj-rmap

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Davide Libenzi wrote:

1) |----------------------|
2) |-----------|
3) |--------------------------|
4) |-----------|

R) |---|---|-------|---|--|---|

    1 1 1 1 1 3
    3 2 2 3 3
        3 3 4
            4

 How's this for an alogorithm for finding which
chunk of 'R' you have hit with a given memory reference:

 o Use a bitmap to represent the whole address range.
 o Set the bits that correspond the the first page
    of each subregion.

 To search:

 o Look up the bit for the page you are interested in.
 o Scan backwards for a 1.
 o Convert bit position to address, this is the
    base of the subregion.

 Since this is i386-only you can play neat assembler
tricks with this code to make it fast.

 (OS/2 did/does it that way.)

--
 Chuck
 I am not a number!
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• Next message: Alan Cox: "PATCH: MOD_* can go for floppy"
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• Maybe in reply to: Martin J. Bligh: "subobj-rmap"
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