Re: Buffer Management

Tom Lane wrote:
> Curt Sampson <cjs(at)cynic(dot)net> writes:
> > Note that your proposal of using mmap to replace sysv shared memory
> > relies on the behaviour I've described too.
>
> True, but I was not envisioning mapping an actual file --- at least
> on HPUX, the only way to generate an arbitrary-sized shared memory
> region is to use MAP_ANONYMOUS and not have the mmap'd area connected
> to any file at all. It's not farfetched to think that this aspect
> of mmap might work differently from mapping pieces of actual files.
>
> In practice of course we'd have to restrict use of any such
> implementation to platforms where mmap behaves reasonably ... according
> to our definition of "reasonably".

Yes, I am told mapping /dev/zero is the same as the anon map.

--
Bruce Momjian | http://candle.pha.pa.us
pgman(at)candle(dot)pha(dot)pa(dot)us | (610) 853-3000
+ If your life is a hard drive, | 830 Blythe Avenue
+ Christ can be your backup. | Drexel Hill, Pennsylvania 19026