Subject: Re: kern/33185: kva shortage problems
To: None <yamt@mwd.biglobe.ne.jp>
From: Izumi Tsutsui <tsutsui@ceres.dti.ne.jp>
List: tech-kern
Date: 05/11/2006 20:08:44
yamt@mwd.biglobe.ne.jp wrote:

> > > a concern is kva fragmentation.
> > 
> > I'm not a VM expert, but "kva fragmentation" reminds me
> > STE shortage on 68040 and sun3x pmaps...

> i'm not sure what's "STE shortage".  can you explain with MI terms? :-)

Well, sun3x uses 7-6-6-13 bits 3-level MMU, and memory
for each Segment Table Entry is allocated statically.
Recently (for a year?) I often got "get_x_tabe: out of X tables."
panics on my 3/80 and I just thought it was caused by kva
fragmentation.
(yes, just sun3x pmap should be fixed, but it's not easy...)

> i don't think my patch makes kva fragmentation much worse.

Ok, then there is no problem on your patch.
Thank you for your explanation.
---
Izumi Tsutsui