Message-ID: <1094217393.41386eb16f9ee@rmc60-231.urz.tu-dresden.de>
Date: Fri,  3 Sep 2004 15:16:33 +0200
From: Hendrik Fehr <s4248297@rcs.urz.tu-dresden.de>
To: linux-kernel@vger.kernel.org
Subject: Re: PROBLEM: Full CPU-usage on sis5513-chipset disc input/output-operations
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Alan Cox writes:
> [...]
> Likewise. So it is booting up with DMA enabled and ought to be fast for
> both devices. What does hdparm -t /dev/hda say ?
> 

bash-2.05b# hdparm -t /dev/hda

/dev/hda:
 Timing buffered disk reads:   72 MB in  3.03 seconds =  23.80 MB/sec

Note: i just added "noapic" to my boot options.

bash-2.05b# cat /proc/cmdline
BOOT_IMAGE=bk8dev26 root=305 psmouse.proto=imps hdc=cdrom ide0=ata66 noapic

I dont know if ~24MB/sec is a good speed, but remember: the cpu is on full
usage
and the BUFF memory usage increases (and is later released again). And as i
wrote to Lionel there seem to be a linear dependency between cpu clock rate and
i/o result. Lionels words to this fact: "There seems to be an unusual amount of
cpu time spent in IRQ processing for your disk drive's accesses but I really
can't put a finger on why."

BTW: those who dont know: i made a nice "bug"-report and put it on:
http://rcswww.urz.tu-dresden.de/~s4248297/gubed/report.html
You will find all the interesting things like dmesg and hdparm -I /dev/hda
output in the "files" section.
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