Clocksource is continuous regardless of the state of the host's TSC. (05aa026a) · Commits · 戴 / test

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>

drivers/lguest/lguest.c

+2 −3

Original line number	Diff line number	Diff line
		@@ -679,6 +679,7 @@ static struct clocksource lguest_clock = {
		.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 @@ static void lguest_time_init(void)
		* 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);

Admin message