Re: 2.6.1-rc1

[Paolo Ornati <ornati@lycos.it>]

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On Wednesday 31 December 2003 14:34, Paolo Ornati wrote:
>
> With 2.6.1-rc1 I have noticed a strange IDE performance change.
>
> Results of "hdparm -t /dev/hda" with 2.6.0 kernel:
> (readahead = 256):		~26.31 MB/s
> (readahead = 128):		~31.82 MB/s
>
> PS = readahead is set to 256 by default on my system, 128 seems to be the
> best value
>
> Results of "hdparm -t /dev/hda" with 2.6.1-rc1 kernel:
> (readahead = 256):		~26.41 MB/s
> (readahead = 128):		~26.27 MB/s
>
....

I have done new interesting tests.

SCRIPT
___________________________________________________________
#!/bin/bash

echo "HD test for linux `uname -r`"
echo

MIN=32
MAX=512

ra=$MIN
while test $ra -le $MAX; do
    hdparm -a $ra /dev/hda > /dev/null;
    echo -n $ra$'\t';
    s1=`hdparm -t /dev/hda | grep 'Timing' | cut -d'=' -f2| cut -d' ' -f2`;
    s2=`hdparm -t /dev/hda | grep 'Timing' | cut -d'=' -f2| cut -d' ' -f2`;
    s=`echo "scale=2; ($s1+$s2)/2" | bc`;
    echo $s;
    ra=$(($ra+32));
done
___________________________________________________________


o Results for 2.6.0 (first column = readahead, second column = MB/s)

HD test for linux 2.6.0

32	13.78
64	31.74
96	31.77
128	31.74
160	31.84
192	31.87
224	31.21
256	26.31
288	21.75
320	27.22
352	27.46
384	31.63
416	28.15
448	28.25
480	31.54
512	26.24


o Results for 2.6.1-rc1

HD test for linux 2.6.1-rc1

32	26.20
64	26.26
96	26.99
128	26.29
160	26.28
192	25.89
224	26.55
256	26.46
288	30.86
320	26.74
352	26.15
384	25.86
416	26.42
448	26.46
480	26.82
512	26.46


A graphic is attached (red = 2.6.0 / green = 2.6.1-rc1 ;)


BYE

-- 
	Paolo Ornati
	Linux v2.4.23



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