Question on GCJ/Boehm Memory Utilization, Part II
Martin Egholm Nielsen
martin@egholm-nielsen.dk
Fri Feb 24 08:58:00 GMT 2006
> Craig Vanderborgh wrote:
(And from a new mail, I noticed :-) )
>> We are already running with GC_free_space_divisor set to 20 in our GCJ
Oh! Didn't notice...
>> build, as you suggested this the last time we were whacked by one of
>> these memory allocation problems. But I am curious - can we expect
>> unpleasant side-effects if we have this parameter set to the
>> "extreme"? What do you thing about this? Is this parameter a subject
>> for a tuning study, or are there some rules of thumb that can be used
>> to guesstimate the best value?
> The higher the divisor, the more often GC will run resulting in less
> real work being done.
But you can always decrease/increase the value at runtime (requires some
CNI/JNI code instructing the GC) to take care of situations where
necessary...
Don't know any rules of thumb - guess it's more or less application and
hw specific (how much memory available, size of allocations, number of
repeatedly dropped blocks, nature of allocation, etc.)
// Martin
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