Messages in this thread |  | | Subject | Re: Adaptec vs Symbios performance | Date | Sun, 04 Nov 2001 13:43:51 -0700 | From | "Justin T. Gibbs" <> |
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>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.
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