Messages in this thread |  | | | Date | Tue, 05 Jul 2005 12:19:25 +0200 | | From | Ondrej Zary <> | | Subject | Re: [git patches] IDE update |
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Jens Axboe wrote: > On Tue, Jul 05 2005, Ondrej Zary wrote: > >>André Tomt wrote: >> >>>Al Boldi wrote: >>> >>> >>>>Bartlomiej Zolnierkiewicz wrote: { >>>> >>>> >>>>>>>On 7/4/05, Al Boldi <a1426z@gawab.com> wrote: >>>>>>>Hdparm -tT gives 38mb/s in 2.4.31 >>>>>>>Cat /dev/hda > /dev/null gives 2% user 33% sys 65% idle >>>>>>> >>>>>>>Hdparm -tT gives 28mb/s in 2.6.12 >>>>>>>Cat /dev/hda > /dev/null gives 2% user 25% sys 0% idle 73% IOWAIT >>> >>> >>>The "hdparm doesn't get as high scores as in 2.4" is a old discussed to >>>death "problem" on LKML. So far nobody has been able to show it affects >>>anything but that pretty useless quasi-benchmark. >>> >> >>No, it's not a problem with hdparm. hdparm only shows that there is >>_really_ a problem: >> >>2.6.12 >>root@pentium:/home/rainbow# time dd if=/dev/hda of=/dev/null bs=512 >>count=1048576 >>1048576+0 records in >>1048576+0 records out >> >>real 0m32.339s >>user 0m1.500s >>sys 0m14.560s >> >>2.4.26 >>root@pentium:/home/rainbow# time dd if=/dev/hda of=/dev/null bs=512 >>count=1048576 >>1048576+0 records in >>1048576+0 records out >> >>real 0m23.858s >>user 0m1.750s >>sys 0m15.180s > > > Perhaps some read-ahead bug. What happens if you use bs=128k for > instance? > Nothing - it's still the same.
root@pentium:/home/rainbow# time dd if=/dev/hda of=/dev/null bs=128k count=4096 4096+0 records in 4096+0 records out
real 0m32.832s user 0m0.040s sys 0m15.670s
-- Ondrej Zary - 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/
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