heap profiling

[Claus Reinke]

> I put the simple version at
> http://hpaste.org/fastcgi/hpaste.fcgi/view?id=26329#a26329
> 
> This one displays much better performance with DList + Writer.Strict
> than List + StrictWriter so I guess it's not too surprising.  However,
> *something* is still generating a lot of lag 

Some lag is to be expected: logging is about creating
and recording data for later use. You'd need  to annotate
your code to measure which parts of lag are not attributable
to the log (for instance, your "m" is passed around a lot
before it gets used). Then you can use "-hblag -hc -L40"
to get lag attributed to cost centers.

Btw, you probably want to be more strict about things
like that sum in the simple version ("return $! (1+x1+..)"),
even a stricter base case ("return $! 1") helps a little, 
suggesting that you might want to think about the 
strictness of your logging tools before you put that
in production.

Hth,
Claus