Re: asymmetric smp

[Warner Losh <imp%bsdimp.com@localhost>]

On Apr 1, 2014, at 5:49 AM, Johnny Billquist <bqt%softjar.se@localhost> wrote:

> Good points.
> Is this the right time to ask why booting NetBSD on a VAX (a 3500) now takes 
> more than 15 minutes? What is the system doing all that time???

FreeBSD used to take forever to boot on certain low-end ARM CPUs with /etc/rc.d 
after it was imported from NetBSD. This was due to crappy root-device 
performance (100kB/s is enough for anybody, right?) and crappy, at the time, 
pmap code that caused excess page traffic in the /etc/rc.d environment. Perhaps 
those areas would be fruitful to profile? Also, there were some inefficiencies 
that were either the result of a botched port, or were basic to the system that 
got fixed. Between fixing all these things, the boot time went from 10 minutes 
down to ~20s.

Warner