[lkml]   [2006]   [Mar]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: Readahead value 128K? (was Re: Drastic Slowdown of 'fseek()' Calls From 2.4 to 2.6 -- VMM Change?)
    On Monday 13 March 2006 9:41am, Mark Lord wrote:
    > Marr wrote:
    > > Anyway, not that it really matters, but I re-did the testing with '-a0'
    > > and it didn't help one iota. The 2.6.13 kernel on ReiserFS (without using
    > > 'nolargeio=1' as a mount option) still takes about 4m35s to fseek 200,000
    > > times on that 4MB file, even with 'hdparm -a0 /dev/hda' in effect.
    > Does it make a difference when done on the filesystem *partition*
    > rather than the base drive? At one time, this mattered, and it may
    > still work that way today.
    > Eg. hdparm -a0 /dev/hda3 rather than hdparm -a0 /dev/hda
    > ??

    Unfortunately, it makes no difference. That is, after successfully setting
    '-a0' on the partition in question (instead of the whole HDD device itself),
    the 200,000 random 'fseek()' calls still take about 4m35s on ReiserFS
    (without using 'nolargeio=1' as a mount option) under kernel 2.6.13.

    P.S. I've CC:ed you and the others on my reply to Al Boldi's request for the
    'hdparm -I /dev/hda' information, in case it helps at all.

    Thanks for your inputs, Mark -- much appreciated!

    *** Please CC: me on replies -- I'm not subscribed.

    Bill Marr
    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: 2006-03-13 21:04    [W:0.024 / U:57.476 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site