Feisty to Gutsy Upgrade - Duo CPU Detection for D620
I completed the upgrade from feisty fawn (4.10) to gutsy gibbon (7.10) over the weekend. There were a few issues - the upgrade hung during the installation of a package and I had to resume it manually using dpkg. This was not really much of a big deal - the same thing happened when I upgraded from edgy.
However today I was sliding my mouse over the KDE Power Manager and I noticed that the CPU Frequency only displayed one processor. Given my Dell D620 came equipped with a duo core processor I took immediate notice. Inspecting /proc/cpuinfo revealed the issue wasn’t with the PowerManager but rather in the CPU detection being performed by the kernel.
It turned out that during the upgrade a 386 kernel was installed and made the default. The 386 kernel lacks duo support (I believe) based on a few things I read on the topic. I rebooted into the generic kernel and the Power Manager displayed the two processors.
After determining that was the problem I removed the 386 kernel from my system which fixed my system to use the correct generic kernel as that was the next one on the list.
I am not sure why the upgrade process nixed the cpu detection but given the ease of the fix not something I will dwell on much. It could have been caused by my interrupted upgrade, the fact my kernel had been patched for vmware, or something wrong with the upgrade process itself.