Re: CPU frequency-changing comes and goes

["Steven M. Bellovin" <smb%cs.columbia.edu@localhost>]

On Mon, 21 Apr 2008 17:12:13 -0400
"Jared D. McNeill" <jmcneill%invisible.ca@localhost> wrote:

> Steven M. Bellovin wrote:
> > Sometimes, when I reboot my laptop (Thinkpad T61 running
> > amd64-4.99.54 at the moment), the kernel doesn't detect speedstep.
> > If I try to run estd, I get
> > 
> >     estd: Cannot guess CPU-scaling technology. (maybe you are
> > missing some kernel-option?)
> > 
> > Similarly, 
> > 
> >     $ sysctl -a|grep freq
> > 
> > gives no output.
> > 
> > It isn't a kernel build option; a reboot will usually bring it back.
> > 
> > I've attached /var/run/dmesg from the last boot.
> 
> When it fails are you booting with the AC adapter unplugged? If so:
> 
>    http://www.netbsd.org/cgi-bin/query-pr-single.pl?number=38360
> 
That could very well be it; I haven't isolated the conditions that
cause it.  I'll watch; thanks.


                --Steve Bellovin, http://www.cs.columbia.edu/~smb