>See:
>
>Date: Wed, 31 Oct 2001 16:45:39 +0100
>From: Stephan von Krawczynski <skraw@ithnet.com>
>To: linux-kernel <linux-kernel@vger.kernel.org>
>Subject: The good, the bad & the ugly (or VM, block devices, and SCSI :-)
>Message-Id: <20011031164539.29c04ee0.skraw@ithnet.com>
<Sigh> I don't read all of the LK list and the mail was not cc'd
to me, so I did not see this thread.
>> A full dmesg would be better. Right now I have no idea what kind
>> of aic7xxx controller you are using,
>
>Adaptec A29160 (see above mail). Remarkably is I have a 32 bit PCI bus, no 64
>bit. This is an Asus CUV4X-D board.
*Please stop editing things*. I need the actual boot messages from
the detection of the aic7xxx card. It would also be nice to see
the output of /proc/scsi/aic7xxx/<card #>
>> the speed and type of CPU,
>
>2 x PIII 1GHz
Dmesg please.
>Sorry, misunderstanding. What I meant was: how fast can you read data
>from your cd-rom attached to some adaptec controller?
I'll run some tests tomorrow at work. I'm sure the results will
be dependent on the cdrom in question but they may show something.
>> >If you redo this test with nfs-load (copy files from some client to your
>> >test-box acting as nfs-server) you will end up at 1926 - 2631 kB/s
>throughput
>> >with aic, but 3395 - 3605 kB/s with symbios.
>>
>> What is the interrupt load during these tests?
>
>How can I present you an exact figure on this?
Isn't there a systat or vmstat equivalent under Linux that gives you
interrupt rates? I'll poke around tomorrow when I'm in front of a Linux
box.
>> Have you verified that
>> disconnection is enabled for all devices on the aic7xxx controller?
>
>yes.
The driver may not be seeing the same things as SCSI-Select for some
strange reason. Again, just email me a full dmesg after a successful
boot along with the /proc/scsi/aic7xxx/ output.
>> This does not look like an interrupt latency problem.
>
>Based on which thoughts?
It really looks like a bug in the driver's round-robin code or perhaps
a difference in how many transactions we allow to be queued in the
untagged case.
Can you re-run your tests with the output directed to /dev/null for cdrom
reads and also perform some benchmarks against your disk? The benchmarks
should operate on one device only at a time with as little I/O to any other
device during the test.
-- Justin - 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/
This archive was generated by hypermail 2b29 : Wed Nov 07 2001 - 21:00:24 EST