Yesterday I switched to the non-smp generic kernel on my Slackware 12.2 virtual machine (VirtualBoxv4.1.18). I've got troubles with the compilation of the GuestAdditions. I investigated the cause and I found such thing. Here is a part from the script which compiles GuestAddition kernel modules
if [ -d "$KERN_DIR" ]; then
KERN_REL=`make -sC $KERN_DIR --no-print-directory kernelrelease 2>/dev/null || true`
if [ -z "$KERN_REL" -o "x$KERN_REL" = "x$KERN_VER" ]; then
printf "\nThe headers for the current running kernel were not found. If the
following\nmodule compilation fails then this could be the reason.\n"
This is the part called 'the sanity' check. The script for non-smp kernel returns the line after the 'printf' command. The problem is that the
'KERN_REL' always have the value with '-smp' postfix added. But for non-smp kernel there is no '-smp' postfix. On my machine
bash$ uname -r
The problem is that compiled modules have inappropriate format and won't be loaded during the boot.