FreeBSD on the AP121 (AR9330)

[Adrian Chadd]

On 27 March 2013 10:16, Ian Lepore <ian at freebsd.org> wrote:

> For starters you might try disabling WITNESS and other things you can't
> afford in a slimmed-down kernel.  On the other hand, kernel bloat is

Well, the only thing I can't really afford here is the -head
debugging. But it doesn't actually slim down things significantly.
I'll re-post the sizes later.

[snip]

> If the system isn't doing heavy IO, try "option NBUF=128" to seriously
> slim down the amount of memory for buffers (by default it'll use 1/4 of
> total ram up to 64MB).  It would be nice to know more about the
> implications of tweaking this number, but when I asked on a mailing list
> once I didn't get much useful info.

There's that; I think the problem here is deadlock if there's not
enough buffers available. Guess that bug should be fixed.

The other immediate thing is the umtx hash array. It's rather large
(512) and it doesn't need to be.

I haven't even started with the subsystem memory allocations yet
either. They get even scarier.

(And userland is doubly-scary on this platform. Sigh.)



Adrian