timekeeping: Maintain ktime_t based offsets for hrtimers
authorThomas Gleixner <tglx@linutronix.de>
Tue, 17 Jul 2012 06:39:52 +0000 (02:39 -0400)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 19 Jul 2012 15:58:59 +0000 (08:58 -0700)
commit7d1f07113b1b32da1eabce0dc74d9f96bbb7b90a
tree6bdc4407079c57126f96c0409eda6e031d618695
parent2e947d469fba2c2036ff50a2e58a1875ab2ea6b6
timekeeping: Maintain ktime_t based offsets for hrtimers

This is a backport of 5b9fe759a678e05be4937ddf03d50e950207c1c0

We need to update the hrtimer clock offsets from the hrtimer interrupt
context. To avoid conversions from timespec to ktime_t maintain a
ktime_t based representation of those offsets in the timekeeper. This
puts the conversion overhead into the code which updates the
underlying offsets and provides fast accessible values in the hrtimer
interrupt.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Prarit Bhargava <prarit@redhat.com>
Link: http://lkml.kernel.org/r/1341960205-56738-4-git-send-email-johnstul@us.ibm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kernel/time/timekeeping.c