lkml.org 
[lkml]   [2003]   [Dec]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRE: more dbt-2 results hyperthreading on linux-2.6.0-test11
    Date
    From
    I'm not familiar with this particular workload, but noticed higher idle
    and wait time with HT enabled, compared to HT-disabled case. This kind
    of symptom often indicated insufficient I/O bandwidth from my
    experience, and faster systems (with more threads) tend to show lower
    throughput because you end up measuring disk seek time of more I/O
    requests. Can you add more disk controller(s) and disks?

    Jun
    > -----Original Message-----
    > From: linux-kernel-owner@vger.kernel.org [mailto:linux-kernel-
    > owner@vger.kernel.org] On Behalf Of markw@osdl.org
    > Sent: Friday, December 12, 2003 2:28 PM
    > To: piggin@cyberone.com.au
    > Cc: mingo@redhat.com; linux-kernel@vger.kernel.org; pgsql-
    > hackers@postgresql.org
    > Subject: more dbt-2 results hyperthreading on linux-2.6.0-test11
    >
    > Hi Nick,
    >
    > Here are the results of the comparisons I said I would do.
    >
    > no-hyperthreading:
    > http://developer.osdl.org/markw/dbt2-pgsql/282/
    > - metric 2288.43
    > - baseline
    >
    > hyperthreading:
    > http://developer.osdl.org/markw/dbt2-pgsql/278/
    > - metric 1944.42
    > - 15% throughput decrease
    >
    > hyperthreading w/ Ingo's C1 patch:
    > http://developer.osdl.org/markw/dbt2-pgsql/277/
    > - metric 1978.39
    > - 13.5% throughput decrease
    >
    > hyperthreading w/ Nick's w26 patch:
    > http://developer.osdl.org/markw/dbt2-pgsql/274/
    > - metric 1955.91
    > - 14.5% throughput decrease
    >
    > It looks like there is some marginal benefit to your or Ingo's patches
    > with a workload like DBT-2. I probably don't understand enough about
    > hyperthreading, but I wonder if there's something PostgreSQL can do to
    > take advantage of hyperthreading
    >
    > Anyway, each link has pointers to readprofile and annotated oprofile
    > assembly output (if you find that useful.) I haven't done enough
    tests
    > to have an idea of the error margin, but I wouldn't be surprised if
    it's
    > at least 1%.
    >
    > Let me know if there's anything else you'd like me to try.
    >
    > Thanks,
    > Mark
    > -
    > 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/
    -
    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 13:59    [W:0.026 / U:29.744 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site