From: Jesper Dangaard Brouer <hawk@diku.dk>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org, netdev <netdev@vger.kernel.org>,
Len Brown <len.brown@intel.com>,
Shaohua Li <shaohua.li@intel.com>,
hawk@comx.dk
Subject: TSC unstable due to TSC halts in idle?
Date: Fri, 14 May 2010 22:13:57 +0200 (CEST) [thread overview]
Message-ID: <Pine.LNX.4.64.1005142208290.6220@ask.diku.dk> (raw)
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
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next reply other threads:[~2010-05-14 20:14 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-14 20:13 Jesper Dangaard Brouer [this message]
2010-05-14 22:28 ` TSC unstable due to TSC halts in idle? john stultz
2010-05-14 23:15 ` Suresh Siddha
2010-05-15 9:54 ` Jesper Dangaard Brouer
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