Subject: Re: Ungraceful low memory issue
To: Havard Eidnes <>
From: Matthew Orgass <>
List: current-users
Date: 08/15/2004 13:57:26
On 2004-08-15 wrote:

> > many many years ago i spent some time trying to determine better values
> > for this but i didn't really discover anything conclusive...
> >
> > however, this shouldn't really affect the pool allocator... we already
> > reserve a bunch of pages for such conditions i thought.
> What if there is a greedy pool memory user around at the time when we
> cross into consuming these "precious/reserve" pool memory resources?
> I might very well imagine that the vnode pool can exhibit this sort of
> behaviour during the first "daily" run which includes a "find / ...".

  Nothing should rely on general use memory being available immediately;
how much general memory to reserve should be entirely a matter of
performance, and it may or may not be the case that increasing such values
will increase performance.  I tend to suspect raising such values would
not help performance even on consistantly heavily loaded systems, since
you could easily just be removing out of memory backpressure and
increasing disk thrashing.  It could, in fact, have a significantly
negative effect.

Matthew Orgass