GC leaks debugging

Erik J Groeneveld erik@cq2.nl
Fri Apr 15 07:32:00 GMT 2011



Op 14 apr. 2011 om 12:49 heeft Andrew Haley <aph@redhat.com> het volgende geschreven:

>>> Why do you want to munmap, anyway?  Are you running out of swap space?
>> 
>> Well, I assume that if the GC unmaps a page (hblk), it can always be
>> mapped at any other location when a new block is needed, effectively
>> circumventing fragmentation completely.
> 
> AFAIK it just returns the memory to the OS;

It turns out it doesn't. It remaps it as not accessible. And it is only doing so after the block hasn't been used for a while. 
And there is some complicated code that seems to remap all such blocks into a larger block.

> I don't think it affects
> anything else.

I am still hoping it does. ;-)

Erik




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