I am attempting to get Slackware-Current Runnning on my acer aspire 5102 (turion x2-50 1.6gh, 1G ram.... I've been running SLAMD64, but ran into a few issues with 32/64 bit libraries (also wanted to try out the new additions to -current.) Anyway, with every recent SMP kernel I try to run, I get an error:

Clocksource tsc unstable (delta ........

This appears during boot below 'freeing unused kernel memory.

After this, the machine apparently stalls, but can be prompted to continue the boot process by repeatedly pressing a key. The computer will boot to X and run, more or less normally, but requires constant input, either moving the mouse or pressing a key to continue operation.

Things I've tried:
kernel boot paramaterss:
clock=pit, clock=tsc, notsc, nohpet, pmtimer, nohpet nopmtimer powernow-k8.tscsync=1.

kernel configuration: I have removed hpet, changed clock resolution, but cannot find any way to get a kernel after 2.6.19 to run properly when compiled for SMP.

Any Ideas?

I have the same symptoms with my acer 5102 (running archlinux) since kernel 2.6.21 .
Other archlinux users also have this problem, and we did find a workaround that works for most :

plug-in a usb-mouse and the problem disappears.

If you want more details, see our bugtracker : http://bugs.archlinux.org/task/7124 .

NOTE : i am aware this is the slackware forum on LQ, but this problem appears to be kernel-related and not distro related.

I have an Aspire 5050 and I resolved this issue by recompiling my kernel WITHOUT SMP support.

Worked like a charm!

Oops! I see that you already know the non-SMP solution. I did read that it had something to do with CPU Frequency scaling, so you could try turning that off in your kernel and recompile..

try appending clocksource=acpi_pm