Re: factor is too fast

[Philip Rowlands]

On Tue, 21 Apr 2009, Toralf F?rster wrote:

> For a long time I used the command "factor" to test my system WRT the cpu
> ondemand governor of the linux kernel, eg for issues like this :
> http://bugzilla.kernel.org/show_bug.cgi?id=12385
>
> However switching from coreutils-6.10 to 7.1 (stable Gentoo Linux) now the
> factor command is too fast: it takes only 0.003 sec instead of 5.5 sec for
> the same prime number.

That's probably due to this entry from NEWS:

* Noteworthy changes in release 7.0 (2008-10-05) [beta]

  If the GNU MP library is available at configure time, factor and
  expr support arbitrarily large numbers.  Pollard's rho algorithm is
  used to factor large numbers.

> Therefore I'm wondering whether you have a hint for me which number I could
> use nowadays ?

If the goal is simply drive the CPU usage to 100% for 5 seconds, this 
would work:

$ timeout 5 factor 20158916322613169725842061629370496430


Cheers,
Phil