From: David Engraf <david.engraf@sysgo.com>
To: John Stultz <johnstul@us.ibm.com>, Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Subject: timekeeping_adjust may set mult to 0
Date: Mon, 11 Feb 2013 16:48:11 +0100 [thread overview]
Message-ID: <511912BB.2060602@sysgo.com> (raw)
Hi,
I have encountered a problem when a linux system uses a clocksource with
mult = 1 and shift = 0 (clocksource cycle = nanoseconds). It may happen
that the function timekeeping_adjust reduces the value of mult to 0 when
error is lower than the interval [1].
As soon as timekeeper.mult is 0, ktime_get will no longer work because
it uses timekeeping_get_ns which converts the cycle to nanoseconds with
mult as 0 and the system clocksource returns always 0.
Best regards
David Engraf
[1] http://lxr.linux.no/linux+v3.0.62/kernel/time/timekeeping.c#L821
next reply other threads:[~2013-02-11 15:57 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-11 15:48 David Engraf [this message]
2013-02-15 22:34 ` timekeeping_adjust may set mult to 0 John Stultz
2013-02-26 13:05 ` David Engraf
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