[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20150817150100.GA31682@openwall.com>
Date: Mon, 17 Aug 2015 18:01:00 +0300
From: Solar Designer <solar@...nwall.com>
To: john-dev@...ts.openwall.com
Subject: Re: FMT_OMP_BAD
On Mon, Aug 17, 2015 at 10:53:06PM +0800, Kai Zhao wrote:
> On my laptop and build with ./configure && make -sj8
>
> $ OMP_NUM_THREADS=1 ../john -test -form=wpapsk
> Warning: OpenMP is disabled; a non-OpenMP build may be faster
> Benchmarking: wpapsk, WPA/WPA2 PSK [PBKDF2-SHA1 256/256 AVX2 8x]... DONE
> Raw: 3232 c/s real, 3232 c/s virtual
>
> $ OMP_NUM_THREADS=10 ../john -test -form=wpapsk
> Will run 10 OpenMP threads
> Benchmarking: wpapsk, WPA/WPA2 PSK [PBKDF2-SHA1 256/256 AVX2 8x]...
> (10xOMP) DONE
> Raw: 9346 c/s real, 2038 c/s virtual
>
> So the wpapsk format should set FAST_FORMATS_OMP and
> FMT_OMP_BAD ?
No. You shouldn't be setting OMP_NUM_THREADS higher than your logical
CPU count for any sort of benchmarking. (You may do so for a
stress-test, when trying to trigger a bug.) Also, your laptop's CPU
almost certainly does not have 8 physical cores (probably it has 4), and
its clock rate likely reduces a lot when you use all 4 cores at once.
wpapsk actually scales very well:
http://www.openwall.com/lists/john-dev/2015/08/17/21
11560/1308 = 8.84
http://www.openwall.com/lists/john-dev/2015/08/16/23
Perfect for this test is 9.39.
8.84/9.39 = 94% of perfect
Alexander
Powered by blists - more mailing lists
Confused about mailing lists and their use?
Read about mailing lists on Wikipedia
and check out these
guidelines on proper formatting of your messages.
