[lkml]   [1999]   [May]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: XFS and journalling filesystems
       Date: 	Mon, 24 May 1999 11:24:35 -0600
    From: Larry McVoy <>

    : (And there are certain features of XFS, such as the features that allow
    : Irix to tell the disk controller to send disk blocks directly to the
    : ethernet controller, which then slaps on the TCP header and calclates
    : the TCP checksum without the disk data ever hitting memory

    This is not quite right, in fact, it is a little unfair to IRIX. There is
    no interaction between the file system and/or the block device system
    and the networking stack. The way it works is this (I know this code
    extremely well since I'm the guy that originally made NFS use both the
    networking and the file system to go at 94MByte/sec - Ethan Solomita is
    the guy who made it go at 640MByte/second over Super HIPPI):

    I stand corrected. I had heard about the zero copy algorithm you
    described, but then when I later heard that Irix had bypassed even the
    DMA in and out of memory, I was appropriately horrified. I'm glad to
    hear it wasn't true, and that you had no part in implementing or
    designing such a horrible hack (i.e., direct device-to-device I/O). :-)

    - Ted

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

     \ /
      Last update: 2005-03-22 13:51    [W:0.019 / U:0.048 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site