🚀 go-pugleaf

In article <713.6612T338T2196@und.ida.liu.se>, c92manen@und.ida.liu.se
(Mans Engman) wrote:

> [snip]
> 
> >I already posted that the Language Systems and Absoft fortran compilers
> >will do exactly what you want. I run many computationally intensive codes
> >on a PowerMac with perfectly smooth background execution "via a simple
> >compilation". The compilers put in the proper code to support the Mac OS
> >multitasking and it works just fine. The source code remains absolutely
> >unchanged portable ANSI 77 fortran.
> 
> "Proper code"?
> 
> Ok, I'm rather ignorant about McI****h programming, but I just wonder
under what
> circumstances the compilers put in that code? Does it put taskswitching code
> every XXX loops? And how can I be sure it doesn't put that code there
when it's
> not necessary?

The flag that controls this has three or four different levels, each of
which has a very clear explanation of exactly when a background call is
made.  For example, the lowest level (I believe) only makes a call when
I/O occurs.  Higher levels include background calls for subroutine
entries, at loops, etc.  Usually, one of the levels will work quite well;
your machine will remain very responsive, and the code will not suffer
much of a speed hit.  For example, I routinely run computational fluids
codes at the second bacground level.  I almost never notice any slowdown
of other (non-intensive) programs, and the codes usually run at about 90%
of full speed (compared to timings when I don't allow background
execution).

It is true I will be very happy when the Mac gets PMT, but really most of
the time CMT works pretty well.  When the System is protected from rogue
applications (Copland), then I will be truly ecstatic. . .

Mike

-- 
Mike Zulauf
mazulauf@atmos.met.utah.edu