Re: Pre-allocation of shared memory ...

On Thu, Jun 12, 2003 at 10:10:02PM -0400, Bruce Momjian wrote:
> Tom Lane wrote:
> > Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> writes:
> > > You have to love that swap + 1/2 ram option --- when you need four
> > > possible options, there is something wrong with your approach. :-)
> >
> > I'm still wondering what the "no overcommit handling" option does,
> > exactly.
>
> I assume it does no kills, and allows you to commit until you run of of
> swap and hang. This might be the BSD 4.4 behavior, actually.

? I thought the idea of no overcommit was that your malloc fails ENOMEM
if there isn't enough memory free for your whole request, rather than
gambling that other processes aren't actually using all of theirs right now
and have pages swapped out. I don't see where the hang comes in..

> It is bad to hang the system, but if it reports swap failure, at least
> the admin knows why it failed, rather than killing random processes.

Yes!

Patrick