lkml.org 
[lkml]   [2003]   [Aug]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] O11int for interactivity


    William Lee Irwin III wrote:

    >On Tue, Aug 05, 2003 at 10:56:16AM +1000, Nick Piggin wrote:
    >
    >>I'm an IO scheduler type person! What help do you need? I haven't been
    >>following the thread.
    >>
    >
    >I'm not sure it was in the thread. Basically, the testers appear to
    >associate skips with changes in writeout and/or readin behavior (either
    >large amounts of writeout or low amounts of readin), though the effect
    >of behavior similar to that surrounding a skip doesn't appear to
    >guarantee a skip.
    >

    Right.

    snip vmstat

    >
    >The load IIRC was some kind of io to an IDE disk while xmms played.
    >
    >About all I can tell is that when there is a skip, bi is low, but
    >the converse does not hold. This appears to be independent of io
    >scheduler (I had them try deadline too), and I'm very unsure what to
    >make of it. I originally suspected thundering herds from waitqueue
    >hashing but things appear to contradict that given the low cs rates.
    >

    So yeah it could easily be that for example the cpu scheduler is
    causing the skip and the low IO rates.

    >
    >I'm collecting instrumentation patches to see what's going on. The
    >first order of business is probably getting the testers to run with
    >sleepometer to see if and where they're blocking, but given the io bits
    >that are observable some elevator instrumentation might help too (and
    >whatever it takes to figure out if a driver is spinning wildly too!).
    >

    Let me know if you come up with anything significant ;)

    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2005-03-22 13:47    [W:0.021 / U:119.776 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site