lkml.org 
[lkml]   [2009]   [Oct]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: IO scheduler based IO controller V10

    * Mike Galbraith <efault@gmx.de> wrote:

    > On Fri, 2009-10-02 at 11:24 +0200, Ingo Molnar wrote:
    > > * Jens Axboe <jens.axboe@oracle.com> wrote:
    > >
    > > > It's not hard to make the latency good, the hard bit is making sure we
    > > > also perform well for all other scenarios.
    > >
    > > Looking at the numbers from Mike:
    > >
    > > | dd competing against perf stat -- konsole -e exec timings, 5 back to
    > > | back runs
    > > | Avg
    > > | before 9.15 14.51 9.39 15.06 9.90 11.6
    > > | after [+patch] 1.76 1.54 1.93 1.88 1.56 1.7
    > >
    > > _PLEASE_ make read latencies this good - the numbers are _vastly_
    > > better. We'll worry about the 'other' things _after_ we've reached good
    > > latencies.
    > >
    > > I thought this principle was a well established basic rule of Linux
    > > IO scheduling. Why do we have to have a 'latency vs. bandwidth'
    > > discussion again and again? I thought latency won hands down.
    >
    > Just a note: In the testing I've done so far, we're better off today
    > than ever, [...]

    Definitely so, and a couple of months ago i've sung praises of that
    progress on the IO/fs latencies front:

    http://lkml.org/lkml/2009/4/9/461

    ... but we are greedy bastards and dont define excellence by how far
    down we have come from but by how high we can still climb ;-)

    Ingo


    \
     
     \ /
      Last update: 2009-10-02 18:41    [W:3.872 / U:0.720 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site