CPU frequency-changing comes and goes

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

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.

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

Attachment: dmesg.boot
Description: Binary data