Re: [dm-crypt] Encryption speed and reversing the direction

On Tue, Aug 25, 2020 at 04:59:29PM +0200, Arno Wagner wrote:
> On Tue, Aug 25, 2020 at 04:44:50 CEST, Eric Biggers wrote:
> > On Tue, Aug 25, 2020 at 02:05:35AM -0400, John Lee McMahon wrote:
> [...]
> > Also if you actually care about random number generation performance, you
> > shouldn't be going through the kernel at all, except to read an initial
> > seed.  
> [...]
> 
> Not anymore. /dev/urandom has pretty good performance now.
> On my very old Phenom II fileserver, I get about 270MB/sec
> with a 5.x kernel.

Sure, just using /dev/urandom (or getrandom()) should be the first choice.
I was talking about the rare case where those still aren't fast enough.

- Eric