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sched: walt: fix window misalignment when HZ=300

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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>
This commit is contained in:
Joonwoo Park
2017-06-01 10:59:12 -07:00
committed by Suren Baghdasaryan
parent 97841e574a
commit d368c6faa1
1 changed files with 8 additions and 0 deletions
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8
kernel/sched/walt.c
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@@ -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