Performance of 4.x vs 5.x (Re: Lifetime of FreeBSD branches)

Freddie Cash fcash at
Tue May 24 12:07:39 PDT 2005

On May 24, 2005 11:39 am, martinko wrote:
> Kris Kennaway wrote:
> > Also try defining PREEMPTION in your kernel on 5.x and above (if you
> > are running i386 or amd64).  There have been very occasional reports
> > of panics with this option enabled (although I use it everywhere and
> > have not seen problems on my heavily loaded machines), but interactive
> > response should be much better.

> i cannot find (a description of) PREEMPTION in NOTES or GENERIC (on 5.4
> on i386).

> am i missing something?

There are two NOTES files for each CPU architecture.

One is for the CPU architecture dependent items and is located 
at /usr/src/sys/<arch>/conf/NOTES  Just replace <arch> with the CPU 
architecture (i386, amd64, etc).

The other is for items that apply to all CPU architectures, and is located 
at /usr/src/sys/conf/NOTES.

You have to read both.  The PREEMPTION option is in the second file above.
Freddie Cash
fcash at

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