[olpc-software] graceful handling of out-of-memory conditions

[Alan Cox]

On Mon, Mar 27, 2006 at 11:19:54AM -0500, Jim Gettys wrote:
> those applications are not even appropriate for the target audience.
> I'm certainly going to talk about this at GUADEC.  I hope observations
> about our memory wastage will be a wakeup call to the community.

With certain notable exceptions (evolution, where even security holes are
being ignored nowdays) the core GNOME has been getting better over time and
some of the really dumb stuff (but not all of it) has gone away. The lower
level stuff like gtk is pretty tight although the string handling stuff seems
to have the odd pathalogical disagreement with the glibc malloc.

> The paging system should be recovering unused pages of text when more
> heap/stack is needed; we certainly observed this behavior on the iPAQ.
> But there comes a minimum point when you end up paging text too much out
> of flash (which wastes power and hurts speed).

We recover roughly on the basis of "Least regularly used" and code pages are
scavenged as well as data.  If you swap is flash you probably want to turn
down some of the swap prefetch/block sizes as those are designed to try
and beat sane performance out of modern hard disks.

Alan