detecting memory size?

Ketil Malde ketil+haskell at
Fri Jan 30 10:04:08 EST 2004

Joachim Durchholz <joachim.durchholz at> writes:

>> What I really want is the amount of
>> memory my application can allocate and excercise lively without
>> causing thrashing.  On my Linux computer, that amounts more or less to
>> the installed, physical RAM, minus a bit, so I'll settle for that. :-)

> An easier way would be to make this a configuration option at
> installation time - the justification being that users probably have a
> better idea of how much RAM should be allowed to the program.

Actually, there is currently a parameter to use at run-time.  The
problem is that it is a time/space trade-off; if this parameter is set
too conservatively, the program will be unnecessarily slow, if too
liberal, the program will thrash, giving you on average about 5% CPU.
In this case, it's better to crash early with OOM.  (And the optimal
setting depends on the data -- not just data size.) 

So the point of this excercise is to attempt to automatically
determine a reasonable default.

If I haven't seen further, it is by standing in the footprints of giants

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