Subject: Re: Asynchronous crypto layer.

From: Sam Leffler <[email-masked]>
Date: Sat, 30 Oct 2004 23:35:28 -0700

James Morris wrote:
> On Fri, 29 Oct 2004, Sam Leffler wrote:
> 
> 
>>And a paper I wrote explains how I fixed many of the problems with the 
>>openbsd code in freebsd.
>>
>>http://www.usenix.org/publications/library/proceedings/bsdcon03/tech/leffler_crypto/leffler_crpto_html/
> 
> 
> Thanks, that's a useful reference.
> 
> For handling overload of crypto hardware, I was thinking of falling back
> to software processing (really, I guess this is just load balancing
> between hardware and software).

I did a prototype scheduler (never committed) that took into account 
per-device performance metrics and outstanding operations.  The s/w 
crypto driver was just part of the mix.  As a result fallback on 
overload and using s/w crypto for small operands (where the setup 
overhead is too costly) just fell out.

	Sam