From: age <ahuisman@cistron.nl>
To: linux-kernel@vger.kernel.org
Subject: Re: READAHEAD
Date: Sat, 01 Nov 2003 10:15:28 +0100 [thread overview]
Message-ID: <bnvtim$pi$1@news.cistron.nl> (raw)
In-Reply-To: 20031031012946.3adedc14.akpm@osdl.org
Andrew Morton wrote:
> Andrew Morton <akpm@osdl.org> wrote:
>
>>Please, just use time, cat, dd, etc.
>>
>> mount /dev/xxx /mnt/yyy
>> dd if=/dev/zero of=/mnt/yyy/x bs=1M count=1024
>> umount /dev/xxx
>> mount /dev/xxx /mnt/yyy
>> time cat /mnt/yyy/x > /dev/null
>
>
> And you can do the same against /dev/hdaN if you have a scratch
> partition; that would be interesting.
Hi Andrew,
Here are the new test results.
hdparm -a0
Timing buffered disk reads: 52 MB in 3.07 seconds = 16.94 MB/sec
wuuk:~# dd if=/dev/zero of=/home/test/test bs=1M count=34000
34000+0 records in
34000+0 records out
35651584000 bytes transferred in 922.018299 seconds (38666894 bytes/sec)
wuuk:~# time cat /home/test/test > /dev/null
real 33m21.785s
user 0m19.263s
sys 16m31.853s
wuuk:~# time rm /home/test/test
real 1m35.676s
user 0m0.001s
sys 0m6.679s
hdparm -a16
Timing buffered disk reads: 120 MB in 3.05 seconds = 39.39 MB/sec
wuuk:~# dd if=/dev/zero of=/home/test/test bs=1M count=34000
34000+0 records in
34000+0 records out
35651584000 bytes transferred in 920.669609 seconds (38723537 bytes/sec)
wuuk:~# time cat /home/test/test > /dev/null
real 22m4.180s
user 0m18.464s
sys 10m42.722s
wuuk:~# time rm /home/test/test
real 1m35.642s
user 0m0.003s
sys 0m6.635s
hdparm -a256
Timing buffered disk reads: 134 MB in 3.00 seconds = 44.61 MB/sec
wuuk:~# dd if=/dev/zero of=/home/test/test bs=1M count=34000
34000+0 records in
34000+0 records out
35651584000 bytes transferred in 920.412114 seconds (38734371 bytes/sec)
wuuk:~# time cat /home/test/test > /dev/null
real 13m24.228s
user 0m10.306s
sys 3m3.256s
wuuk:~# time rm /home/test/test
real 1m35.900s
user 0m0.002s
sys 0m6.695s
hdparm -a4096
Timing buffered disk reads: 168 MB in 3.01 seconds = 55.82 MB/sec
wuuk:~# dd if=/dev/zero of=/home/test/test bs=1M count=34000
34000+0 records in
34000+0 records out
35651584000 bytes transferred in 920.198902 seconds (38743346 bytes/sec)
wuuk:~# time cat /home/test/test > /dev/null
real 15m25.848s
user 0m10.716s
sys 3m5.103s
wuuk:~# time rm /home/test/test
real 1m36.205s
user 0m0.003s
sys 0m6.743s
I think you were right :-)
groetjes,
Age Huisman
next prev parent reply other threads:[~2003-11-01 9:15 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-10-30 19:23 READAHEAD age
2003-10-30 21:44 ` READAHEAD Andrew Morton
2003-10-31 7:43 ` READAHEAD Nuno Silva
2003-10-31 8:03 ` READAHEAD Andrew Morton
2003-10-31 12:20 ` READAHEAD age
2003-10-31 9:28 ` READAHEAD Andrew Morton
2003-10-31 9:29 ` READAHEAD Andrew Morton
2003-11-01 9:15 ` age [this message]
2003-11-03 0:15 ` READAHEAD Derek Foreman
-- strict thread matches above, loose matches on Subject: below --
2005-09-27 2:38 Readahead Alan Stern
2005-09-27 3:06 ` Readahead Randy.Dunlap
2005-09-27 4:24 ` Readahead Andrew Morton
2005-09-28 18:40 ` Readahead Alan Stern
2003-11-01 17:22 READAHEAD Voluspa
2002-04-16 20:21 readahead Andries.Brouwer
2002-04-16 19:10 readahead Andries.Brouwer
2002-04-16 19:23 ` readahead Andrew Morton
2002-04-16 19:33 ` readahead Jens Axboe
2002-04-16 13:54 readahead Andries.Brouwer
2002-04-16 16:08 ` readahead Steven Cole
2002-04-16 18:25 ` readahead Andrew Morton
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