diff options
Diffstat (limited to 'kernel/sched/walt.c')
| -rw-r--r-- | kernel/sched/walt.c | 46 |
1 files changed, 28 insertions, 18 deletions
diff --git a/kernel/sched/walt.c b/kernel/sched/walt.c index 93f61486f989..8d25ffbe4fed 100644 --- a/kernel/sched/walt.c +++ b/kernel/sched/walt.c @@ -41,25 +41,17 @@ static __read_mostly unsigned int walt_io_is_busy = 0; unsigned int sysctl_sched_walt_init_task_load_pct = 15; -/* 1 -> use PELT based load stats, 0 -> use window-based load stats */ -unsigned int __read_mostly walt_disabled = 0; +/* true -> use PELT based load stats, false -> use window-based load stats */ +bool __read_mostly walt_disabled = false; -/* Window size (in ns) */ -__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. + * Window size (in ns). Adjust for the tick size so that the window + * rollover occurs just before the tick boundary. */ -#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 +__read_mostly unsigned int walt_ravg_window = + (20000000 / TICK_NSEC) * TICK_NSEC; +#define MIN_SCHED_RAVG_WINDOW ((10000000 / TICK_NSEC) * TICK_NSEC) +#define MAX_SCHED_RAVG_WINDOW ((1000000000 / TICK_NSEC) * TICK_NSEC) static unsigned int sync_cpu; static ktime_t ktime_last; @@ -180,10 +172,28 @@ static int exiting_task(struct task_struct *p) static int __init set_walt_ravg_window(char *str) { + unsigned int adj_window; + bool no_walt = walt_disabled; + get_option(&str, &walt_ravg_window); - walt_disabled = (walt_ravg_window < MIN_SCHED_RAVG_WINDOW || - walt_ravg_window > MAX_SCHED_RAVG_WINDOW); + /* Adjust for CONFIG_HZ */ + adj_window = (walt_ravg_window / TICK_NSEC) * TICK_NSEC; + + /* Warn if we're a bit too far away from the expected window size */ + WARN(adj_window < walt_ravg_window - NSEC_PER_MSEC, + "tick-adjusted window size %u, original was %u\n", adj_window, + walt_ravg_window); + + walt_ravg_window = adj_window; + + walt_disabled = walt_disabled || + (walt_ravg_window < MIN_SCHED_RAVG_WINDOW || + walt_ravg_window > MAX_SCHED_RAVG_WINDOW); + + WARN(!no_walt && walt_disabled, + "invalid window size, disabling WALT\n"); + return 0; } |