Commit d368c6fa authored Jun 01, 2017 by Joonwoo Park Committed by Suren Baghdasaryan Jul 12, 2017

sched: walt: fix window misalignment when HZ=300



Due to rounding error hrtimer tick interval becomes 3333333 ns when HZ=300.
Consequently the tick time stamp nearest to the WALT's default window size
20ms will be also 19999998 (3333333 * 6).

Change-Id: I08f9bd2dbecccbb683e4490d06d8b0da703d3ab2
Suggested-by: Joel Fernandes <joelaf@google.com>
Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>

parent 97841e57

kernel/sched/walt.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -72,7 +72,15 @@ static cpumask_t mpc_mask = CPU_MASK_ALL;
		__read_mostly unsigned int walt_ravg_window = 20000000;

		/* Min window size (in ns) = 10ms */
		#ifdef CONFIG_HZ_300
		/*
		* Tick interval becomes to 3333333 due to
		* rounding error when HZ=300.
		*/
		#define MIN_SCHED_RAVG_WINDOW (3333333 * 6)
		#else
		#define MIN_SCHED_RAVG_WINDOW 10000000
		#endif

		/* Max window size (in ns) = 1s */
		#define MAX_SCHED_RAVG_WINDOW 1000000000