I tried 2.6.24.5-85.fc8 with your patch, and I can no longer reproduce
this problem. I think the problem has been solved.
Also, workaround till your patch is applied to distro kernels seems to be
to add "clocksource=jiffies" or something to avoid using tsc as clocksource.
Fedora 9's 2.6.25-14.fc9 also hangs since the default clocksource is tsc, but
with "clocksource=jiffies" added, I encounter no hangs so far.
From today, I can compile kernels using 2 CPUs.
Thank you very much.
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