factor is too fast
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. Therefore I'm wondering whether you have a hint for me which number I could use nowadays ? :-) Thx -- MfG/Sincerely Toralf Förster pgp finger print: 7B1A 07F4 EC82 0F90 D4C2 8936 872A E508 7DB6 9DA3 ___ Bug-coreutils mailing list Bug-coreutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-coreutils
Re: factor is too fast
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 ___ Bug-coreutils mailing list Bug-coreutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-coreutils
Re: factor is too fast
On Tuesday 21 April 2009 08:19:23 Philip Rowlands wrote: > 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. if GMP is too fast, then you could try building coreutils with USE=gmp. if coreutils itself got a new algo, then i guess save the old binary ... -mike signature.asc Description: This is a digitally signed message part. ___ Bug-coreutils mailing list Bug-coreutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-coreutils
Re: factor is too fast
At Monday 27 April 2009 08:35:11 Mike Frysinger wrote : > On Tuesday 21 April 2009 08:19:23 Philip Rowlands wrote: > > 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. > > if GMP is too fast, then you could try building coreutils with USE=gmp. if > coreutils itself got a new algo, then i guess save the old binary ... > -mike Thx, I like this speed improvement in general - and this was really impressive - and b/c I was pointed to the command timeout BTW this has the advantage that I do not have to wait 3x longer (600 MHz versus 1700 MZh) to realize that the ondemand governor doesn't work :-) -- MfG/Sincerely Toralf Förster pgp finger print: 7B1A 07F4 EC82 0F90 D4C2 8936 872A E508 7DB6 9DA3 ___ Bug-coreutils mailing list Bug-coreutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-coreutils