Re: GNAT's stack checking in Ubuntu 9.04 (and Shootout regex-dna)

[jonathan <johnscpg@googlemail.com>]

On Aug 11, 9:02 pm, jonathan <johns...@googlemail.com> wrote:
> On Aug 11, 12:34 am, Georg Bauhaus <rm.tsoh.plus-
>
> bug.bauh...@maps.futureapps.de> wrote:
> > Does regexdna-multi.ada work on your system?
>
> > On a dual core system it seems to be shortening
> > the running time by almost a third.

Final report (this time I mean it):

I tested regexdna-multi.ada on an older dual-core machine
I have access to.  It is almost exactly half as fast (per core)
as the quad-core I used previously.  Main question: is
3 tasks better than 2 at exploiting parallelism. On the
8-core machine, 9 tasks was optimal.

On the dual-core the answer is yes, but the benefit is
much smaller here:

1 task running time: 59 sec
2 task running time: 37.5 sec
3 task running time: 35 sec

where number of tasks is set by Max_CPUs.

Jonathan