[LinuxPPS] comfortable switch of clocksource ?

[Bernhard Schiffner]

Hi,

fiddling with Linux 2.6.19+rt1+linuxpps at X86 I want switch the clocksource 
back to TSC.

Switching clocksources depends from a commandline-parameter for booting and 
can be done (is done) while booting.

kernel-parameters.txt:
clocksource=	[GENERIC_TIME] Override the default clocksource
			Override the default clocksource and use the clocksource
			with the name specified.

Is there any comfortable way known to switch, while the system is running?
 (a la echo tsc >/proc/clocksoure)

tia!

Bernhard