[dm-devel] Re: 2.6.24 Kernel Soft Lock Up with heavy I/O in dm-crypt

[Yan Li]

Hi Milan,

On Mon, Jun 02, 2008 at 08:52:00AM +0200, Milan Broz wrote:
> Please could you try if  patch here helps and doesn't cause performance degradation?
> http://www2.kernel.org/pub/linux/kernel/people/agk/patches/2.6/2.6.25/dm-crypt-add-cond_resched.patch

Will the result of testing a Debian 2.6.24-etchnhalf.1-amd64 kernel
(very near a vanilla kernel) be of same value?  Since the data on some
other drives on this server is important so I dare not try 2.6.25-rc
on it.

Following is my test plan, comments are welcomed:

Test command:
# dd if=/dev/zero of=/dev/mapper/open_device bs=500M count=10
(this server has 2G memory)

The command will be run	for 3 times, and average speed of last two
runs will be taken as result score.

Dm-crypt LUKS Encryption scenarios:
aes-cbc-essiv:sha256, keysize 128
aes-xts-plain, keysize 256
aes-xts-plain, keysize 512

I will compare the speed of all above 3 encryption scenarios, with and
without the patch.

--
Li, Yan