Openwall GNU/*/Linux - a small security-enhanced Linux distro for servers
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Sun, 8 Jul 2012 09:30:03 +0400
From: Solar Designer <solar@...nwall.com>
To: john-dev@...ts.openwall.com
Subject: Re: RAdmin, SIP speedup

Jim -

On Sat, Jul 07, 2012 at 09:58:36PM -0500, jfoug wrote:
> Here is an update to dynamic.
> 
> $ ../run/john -test=5 -form=dynamic_1010
> Benchmarking: dynamic_1010 dynamic_1010: RAdmin v2.x MD5 [32/32 128x1
> (MD5_Body)]... DONE
> Raw:    2117K c/s real, 2122K c/s virtual
> 
> $ ../run/john -test=5 -form=dynamic_1011
> Benchmarking: dynamic_1011 dynamic_1011: RAdmin v2.x MD5 [32/32 128x1
> (MD5_Body)]... DONE
> Raw:    2582K c/s real, 2587K c/s virtual

Maybe you should make your dynamic_1011 the new dynamic_1010 instead,
when you commit this?  That is, have just one dynamic format for RAdmin.

> Func=DynamicFunc__set_input_len_100

Maybe we need to support something like:

Func=DynamicFunc__set_input_len(100)

> And here is the set_input_len_100().  It now keeps data from the prior
> password cleaned up.  No reason to memset the buffers each time (100bytes is
> large for the memset).

Perhaps the same applies to _64 as well?

> >Benchmarking: RAdmin v2.x MD5 [32/64]... (8xOMP) DONE
> >Raw:    10754K c/s real, 1344K c/s virtual
> 
> Yes, it is 'faster', but you are burning all 8 cores, for just a 3x
> improvement,

Sure.  It's this way for many of the fast hashes for which we have
OpenMP support in jumbo.  Personally, I wouldn't use this kind of
parallelization except maybe for really quick tests where I'm lazy to do
anything smarter and when I have the machine to waste anyway.

BTW, note that this is not a true 8-core machine (it's Bulldozer with
its 4 modules and 2 cores per module; also it reduces clock rate from
4.0 GHz to 3.1 GHz or maybe slightly higher when under full load), so
the perfect speedup would be about 6x.  Thus, 3x is "only" twice worse
than perfect.

> and with the dynamic changes I propose, you are probably only
> get a 2.5x improvement, again, burning all 8 cores.  

I thought dynamic didn't support OpenMP at all.  Is this changing?
That would be very nice, especially for phpass.

On a related note, you could want to see if SIP is implementable as a
dynamic too.  I think it might be.

Thanks,

Alexander

Powered by blists - more mailing lists

Your e-mail address:

Powered by Openwall GNU/*/Linux - Powered by OpenVZ