diff options
Diffstat (limited to 'drivers/cpuidle/governors/menu.c')
| -rw-r--r-- | drivers/cpuidle/governors/menu.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c index 68104434ebb5..1aea7157d8ff 100644 --- a/drivers/cpuidle/governors/menu.c +++ b/drivers/cpuidle/governors/menu.c @@ -18,6 +18,7 @@ #include <linux/hrtimer.h> #include <linux/tick.h> #include <linux/sched.h> +#include <linux/math64.h> #define BUCKETS 12 #define RESOLUTION 1024 @@ -99,8 +100,8 @@ struct menu_device { int needs_update; unsigned int expected_us; - u64 predicted_us; unsigned int measured_us; + u64 predicted_us; unsigned int exit_us; unsigned int bucket; u64 correction_factor[BUCKETS]; @@ -169,6 +170,12 @@ static DEFINE_PER_CPU(struct menu_device, menu_devices); static void menu_update(struct cpuidle_device *dev); +/* This implements DIV_ROUND_CLOSEST but avoids 64 bit division */ +static u64 div_round64(u64 dividend, u32 divisor) +{ + return div_u64(dividend + (divisor / 2), divisor); +} + /** * menu_select - selects the next idle state to enter * @dev: the CPU @@ -209,9 +216,8 @@ static int menu_select(struct cpuidle_device *dev) data->correction_factor[data->bucket] = RESOLUTION * DECAY; /* Make sure to round up for half microseconds */ - data->predicted_us = DIV_ROUND_CLOSEST( - data->expected_us * data->correction_factor[data->bucket], - RESOLUTION * DECAY); + data->predicted_us = div_round64(data->expected_us * data->correction_factor[data->bucket], + RESOLUTION * DECAY); /* * We want to default to C1 (hlt), not to busy polling |