Re: Performance degradation with FFSB between 2.6.20 and 2.6.21-rc7

From: Valerie Clement
Date: Thu Apr 19 2007 - 08:46:15 EST


Jens Axboe wrote:
On Thu, Apr 19 2007, Valerie Clement wrote:
Jens Axboe wrote:
Please tell me how you are running ffsb, and also please include a
dmessg from a booted system.

Hi,
our mails crossed! please see my response to Andrew.
You could reproduce the problem with dd command as suggested, it's more easy.
I'm sending you the dmesg info. For my tests I used the scsci sdc device.

Thanks, it does. Can you try one thing for me? If you run the test on
sdc, try doing:

# echo 64 > /sys/block/sdc/queue/iosched/quantum

and repeat the test.


OK, that's done.

With the change of quantum, the throughput scores are now a little bit better in 2.6.21 than in 2.6.20.

Valérie

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/