Clocksource is continuous regardless of the state of the host's TSC.
Currently lguest will spend a lot of of time waking up the host, as it
cannot go tickless (if the [host] TSC has been marked unstable). On my
laptop I was getting ~40% of wakeups from lguest.
With this patch applied, my laptop is much happier!
Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/drivers/lguest/lguest.c b/drivers/lguest/lguest.c
index c9ca610..8e9e485 100644
--- a/drivers/lguest/lguest.c
+++ b/drivers/lguest/lguest.c
@@ -679,6 +679,7 @@
.mask = CLOCKSOURCE_MASK(64),
.mult = 1 << 22,
.shift = 22,
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
/* The "scheduler clock" is just our real clock, adjusted to start at zero */
@@ -760,11 +761,9 @@
* the TSC, otherwise it's a dumb nanosecond-resolution clock. Either
* way, the "rating" is initialized so high that it's always chosen
* over any other clocksource. */
- if (lguest_data.tsc_khz) {
+ if (lguest_data.tsc_khz)
lguest_clock.mult = clocksource_khz2mult(lguest_data.tsc_khz,
lguest_clock.shift);
- lguest_clock.flags = CLOCK_SOURCE_IS_CONTINUOUS;
- }
clock_base = lguest_clock_read();
clocksource_register(&lguest_clock);