Re: [RFC PATCH v5] IV Generation algorithms for dm-crypt

From: Binoy Jayan
Date: Thu Apr 13 2017 - 04:47:05 EST


Hi Milan,

On 10 April 2017 at 19:30, Milan Broz <gmazyland@xxxxxxxxx> wrote:

Thank you for the reply.

> Well, it is good that there is no performance degradation but it
> would be nice to have some user of it that proves it is really
> working for your hw.

I have been able to get access to a hardware with IV generation support
a few days back. The hardware I was having before did not have IV
generation support. Will be able to come up with numbers after making
it work with the new one.

> FYI - with patch that increases dmcrypt sector size to 4k
> I can see improvement in speed usually in 5-15% with sync AES-NI
> (depends on access pattern), with dmcrypt mapped to memory
> it is even close to 20% speed up (but such a configuration is
> completely artificial).
>
> I wonder why increased dmcrypt sector size does not work for your hw,
> it should help as well (and can be combiuned later with this IV approach).
> (For native 4k drives this should be used in future anyway...)

I think it should work well too with backward incompatibility.

Thanks,
Binoy