Comment 111 for bug 595047

On my computer on 2.6.20 kernel jiffies was the default scheduler. Since 2.6.22 hpet is. On my old notebook it is now acpi_pm. I don't known what it was before. With jiffies under 2.6.28, my system seems much better, although there are still some short freezes. It does not solve the problem, but makes it much better. Please try clocksource=jiffies .

You can check yout current clocksource with.
cat /sys/devices/system/clocksource/clocksource0/*

jiffies
645 / 598.3 / 462.5 / 1496.2 / 213.2 / 1353.1 / 6470.6 / 337.6 / 3406.9 / 2057.5 / 155.3 / 309 / 2332 / 463.1 / 1804.4 / 3258.6 / 261.7 / 8124.3 / 2373.2 / 2471.1
min:116.1 ms|max:8124.3 ms|avg:1843.32

The long values are freezes of firefox.
hpet 39790.7
acpi_pm 16303.8
jiffies 8124.3