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Re: Question on GCJ/Boehm Memory Utilization, Part II


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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