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

Matthias Buelow mkb at
Mon May 23 15:14:13 PDT 2005

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 now did this on 5.4-STABLE and I cannot observe any difference.  The
lags still happen in the same way.  The only difference seems to be that
 with PREEMPTION, at and shortly after boot, response seems to be
actually worse and from harddisk noise it doesn't seem to load stuff in
one go but in "chunks" (at least that's how it sounds).  That normalizes
after a while, though.  Weird.


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