[lkml]   [2001]   [Dec]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: [reiserfs-dev] Re: Ext2 directory index: ALS paper and benchmarks

    On Sun, 9 Dec 2001, Daniel Phillips wrote:
    > Continuing the little warts list, there's Alan's comment re needing endian
    > reversal on big endian machines.

    Now that's a load of bollocks.

    We _already_ keep the in-memory data in "disk format", and for a very
    simple reason: that way we can naturally share all the functions that take
    a pointer to a block tree, and they don't need to care whether the block
    numbers come from a disk buffer or from the inode.

    Which means that we have only _one_ set of routines for handling block
    allocation etc, instead of duplicating them all.

    Having in-core data in CPU-native byte order is _stupid_. We used to do
    that, and I winced every time I had to look at all the duplication of
    functions. I think it was early 2.3.x when Ingo did the page cache write
    stuff where I fixed that - the people who had done the original ext2
    endianness patches were just fairly lacking in brains (Hi, Davem ;), and
    didn't realize that keeping inode data in host order was the fundamental
    problem that caused them to have to duplicate all the functions.

    So the _wart_ is in 2.2.x, which is just stupid and ugly, and keeps block
    numbers in host data format - which causes no end of trouble. 2.4.x
    doesn't have this problem, and could easily have a pointer to the on-disk


    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    More majordomo info at
    Please read the FAQ at

     \ /
      Last update: 2005-03-22 13:14    [W:3.255 / U:1.032 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site