Locking a file backed mdconfig into memory

[John Baldwin]

On Friday 04 June 2010 5:37:14 am Dave Hayes wrote:
> John Baldwin <jhb at freebsd.org> writes:
> > On Wednesday 02 June 2010 6:37:59 pm Dave Hayes wrote:
> >> John Baldwin <jhb at freebsd.org> writes:
> >> > Ok, if you are using a stock mfsroot from a release build, that should
> >> > work fine.  If you have built a custom mfsroot that is larger, then
> >> > you may need to increase NKPT on i386.  In very recent 7 and later you
> >> > can do this by setting it to a new value in your kernel config.  In
> >> > older versions you can do this by manually adding a #define to set a
> >> > new value of NKPT in opt_global.h or hacking on the source directly.
> >> 
> >> Is this also true for amd64 (which is my particular target)?
> >
> > It might be.  What is the panic you are seeing?
> 
> I can't see the panic as it repeatedly scrolls across the console screen
> faster than I can read it. In this case the mfsroot is around 275MB. 
> 
> I have noticed that sometimes I can build an mfsroot that does not crash
> of this size.

Hmmm, I would just try increasing NKPT then.  You might have to poke around in 
sys/amd64 to see what the default size is and how to tune it.

-- 
John Baldwin