Re: Re: Re: Memory usage and perl

in reply to Re: Re: Memory usage and perl
in thread Memory usage and perl

fokat++ ... but just to nitpick mmap and certain mallocs (and under certain conditions) will return the memory to the system. Check out the Unix Programming FAQ section 1.12.

-derby

Comment on Re: Re: Re: Memory usage and perl

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Re^4: Memory usage and perl by fokat (Deacon) on Mar 15, 2003 at 16:12 UTC
Thanks a lot for the reference, derby (and ++ for your nitpicking). I have a small difference, though... Actually, `mmap()` does not allocate memory. What it does is map pages belonging to a file, probably from the buffer cache, into your process' private address space. Certainly it is a neat trick, but might have undesired side effects when competing with file-related resources in the same machine, specially with a static buffer cache. They will "return" the memory to the OS because the memory was not originally allocated to your process. I am glad to see certain implementations of `malloc()` and `free()` taking advantage of this. Best regards -lem, but some call me fokat	[reply]

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Re^4: Memory usage and perl
by fokat (Deacon) on Mar 15, 2003 at 16:12 UTC

Thanks a lot for the reference, derby (and ++ for your nitpicking). I have a small difference, though...

Actually, mmap() does not allocate memory. What it does is map pages belonging to a file, probably from the buffer cache, into your process' private address space. Certainly it is a neat trick, but might have undesired side effects when competing with file-related resources in the same machine, specially with a static buffer cache.

They will "return" the memory to the OS because the memory was not originally allocated to your process. I am glad to see certain implementations of malloc() and free() taking advantage of this.

Best regards

-lem, but some call me fokat

[reply]

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