panic: kmem_map too small: the downside of FreeBSD 5

[Jeff Roberson]

On Fri, 13 Jun 2003, Terry Lambert wrote:

> John Hay wrote:
> > On a 5.1-RELEASE machine I have been able to cause a panic like this:
> > panic: kmem_malloc(4096): kmem_map too small: 28610560 total allocated
>
> Manually tune your system.  This panic results from the fact
> that zone allocations with fixed limits don't really do the
> right thing any more, now that it's possible to implement the
> map entry allocations at interrupt.

This is FUD.

> the deprecation of the zalloci() interface that accompanied it,
> an audit should have been done of the system to go through all
> previous places zalloci() was used, and make them robust in case
> of a NULL return value (allocation failure), since those places
> were effectively promised by zalloci() that allocations would
> never fail for this reason.
>

They would fail before.  This is FUD.


More FUD was deleted.

5.0 simply consumes more memory than 4.x.  Unfortunately even with kernel
memory taking up 1/3rd of your resources we are not able to satisfy all
requests.

Some tuning of various memory consumers would be required to get this back
down.  I think this is a worthwhile effort as we should be able to run on
a 32mb system still.

Please note that I'm about to get on a plane and I will probably not reply
to this message.

Thanks,
Jeff