Re: [HACKERS] mmap and MAP_ANON

Bruce Momjian wrote:
>
> Would people tell me what platforms do NOT support the MAP_ANON flag to
> the mmap() system call?  You should find it in the mmap() manual page.
>
> *BSD has it, but I am not sure of the others.  I am researching cache
> size issues and the use of mmap vs. SYSV shared memory.

Well, I haven't noticed this discussion. However, I can't understand one
thing:

Why a lot of people investigate how to replace shared memory with
mmapping anonymously but there is no discussion on replacing
reads/writes with memory mapping of heap files.

This way we would save not only on having better system cache
utilisation but also we would have less memory copying. For me it seems
like a more robust solution. I suggested it few months ago.

If it's a bad idea, I wonder why?
Are there any systems that cannot do mmaps at all?

Mike

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add: Michal Mosiewicz  *  Bugaj 66 m.54 *  95-200 Pabianice  *  POLAND