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

Arjan Van Leeuwen avleeuwen at
Fri May 27 12:38:31 PDT 2005

On 5/26/05, Matthias Buelow <mkb at> wrote:
> >> Others don't see this though, and in other cases it was *definitively
> >> proven* to be caused by the issue I mentioned.  I'll have to think
> >> more about what to try next..thanks for running the tests.
> >
> > Perhaps it's something SATA-related?
> Before restoring my 5.4 dumps after testing -current, I installed
> fedora3 linux just to verify it isn't somehow the hardware itself.  Ok,
> plain installation from CDs, kernel "2.6.9-1.667smp" (default
> installation kernel).  There was absolutely zero noticable lag or any
> effect on response time on X11 while untarring the same firefox source.
>   So there really seems to be something foul in FreeBSD in that regard.
>   And now for the dumps.. *sigh*.

I have the same problem (and have had it for a long time) on both my
dual Xeon 550MHz and Athlon XP 2000+ machines. I'm running 6-CURRENT
(perhaps this thread should move to the -CURRENT list). I'm working on
the dual Xeon right now, so here are some data points from that
- I only see it when there is heavy file activity, for example
untarring firefox or untarring X. Probably because these have a lot of
small files.
- I do not see it when compiling world or doing other compiles
- I don't have any shared irqs.
- I don't have an excessive amount of interrupts, not on the USB irq
nor on any other irq channels.

I think I remember someone (Scott? Jeff? Don Lewis?) mentioning the
problem on another mailing list, and noting that it is a problem with
the filesystem that is difficult to fix. I'll try to find that post.


More information about the freebsd-stable mailing list