TSC unstable due to TSC halts in idle?

[Jesper Dangaard Brouer]

Hi Thomas,

I want to know, if its safe to enable the TSC clocksource, when the
kernel reports:
 "Marking TSC unstable due to TSC halts in idle"

The system selects HPET (in current_clocksource), but I can still see
TSC as an available clocksource (in
/sys/devices/system/clocksource/clocksource0/available_clocksource).

Is it safe to enable TSC manually (by changing current_clocksource)?
(my workload is 10Git/s routing, cannot survive with a slow clock)


Any trick to avoid this? (e.g. kernel config setting, or a /sys/ setting
which changes the minimum P-state?)


The system is a new HP370-G6 server, with two Xeon X5550 CPUs.  Its
(currently) running a Debian compiled kernel 2.6.26-2-amd64.

Kernel log:
 checking TSC synchronization [CPU#0 -> CPU#1]: passed.
 checking TSC synchronization [CPU#0 -> CPU#2]: passed.
 ...
 checking TSC synchronization [CPU#0 -> CPU#14]: passed.
 checking TSC synchronization [CPU#0 -> CPU#15]: passed.
 Marking TSC unstable due to TSC halts in idle


Cheers,
  Jesper Brouer

--
-------------------------------------------------------------------
MSc. Master of Computer Science
Dept. of Computer Science, University of Copenhagen
Author of http://www.adsl-optimizer.dk
-------------------------------------------------------------------
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/