[dm-devel] How to track down abysmal performance ata - raid1 - crypto - vg/lv - xfs

[Mike Snitzer]

On Wed, Aug 04 2010 at  7:53am -0400,
Mikael Abrahamsson <swmike at swm.pp.se> wrote:

> On Wed, 4 Aug 2010, Christoph Hellwig wrote:
> 
> >The good news is that you have it tracked down, the bad news is
> >that I know very little about dm-crypt.  Maybe the issue is the
> >single threaded decryption in dm-crypt?  Can you check how much
> >CPU time the dm crypt kernel thread uses?
> 
> I'm not sure it's that. I have a Core i5 with AES-NI and that didn't
> significantly increase my overall performance, as it's not there the
> bottleneck is (at least in my system).

You could try applying both of these patches that are pending review for
hopeful inclussion in 2.6.36:

https://patchwork.kernel.org/patch/103404/
https://patchwork.kernel.org/patch/112657/