clockevents: Make minimum delay adjustments configurable
The automatic increase of the min_delta_ns of a clockevents device
should be done in the clockevents code as the minimum delay is an
attribute of the clockevents device.
In addition not all architectures want the automatic adjustment, on a
massively virtualized system it can happen that the programming of a
clock event fails several times in a row because the virtual cpu has
been rescheduled quickly enough. In that case the minimum delay will
erroneously be increased with no way back. The new config symbol
GENERIC_CLOCKEVENTS_MIN_ADJUST is used to enable the automatic
adjustment. The config option is selected only for x86.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: john stultz <johnstul@us.ibm.com>
Link: http://lkml.kernel.org/r/20110823133142.494157493@de.ibm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index 119528d..da6c9ec 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -94,7 +94,7 @@
*/
next = ktime_add(dev->next_event, tick_period);
for (;;) {
- if (!clockevents_program_event(dev, next, ktime_get()))
+ if (!clockevents_program_event(dev, next, false))
return;
/*
* Have to be careful here. If we're in oneshot mode,
@@ -137,7 +137,7 @@
clockevents_set_mode(dev, CLOCK_EVT_MODE_ONESHOT);
for (;;) {
- if (!clockevents_program_event(dev, next, ktime_get()))
+ if (!clockevents_program_event(dev, next, false))
return;
next = ktime_add(next, tick_period);
}
