Re: performance issues

> 2. If you are on a platform where the kernel thinks it can swap out
> parts of shared memory (which is most platforms, these days), it's
> counterproductive to make your shared mem large enough that it's not
> all being used heavily.  If the kernel decides to swap out some buffer
> space, you have a net loss in performance, because you just wasted
> disk I/O (especially if the page in the buffer is dirty --- it'll
> eventually have to be read in again, then written out again, to no
> purpose).

FYI, FreeBSD had the ability to disable shared memory swapping with a
sysctl setting, while BSD/OS does not swap out shared memory.

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