| viresh kumar | 2aacdff | 2012-10-23 01:28:05 +0200 | [diff] [blame^] | 1 | /* |
| 2 | * drivers/cpufreq/cpufreq_governor.c |
| 3 | * |
| 4 | * CPUFREQ governors common code |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 as |
| 8 | * published by the Free Software Foundation. |
| 9 | */ |
| 10 | |
| 11 | #include <asm/cputime.h> |
| 12 | #include <linux/export.h> |
| 13 | #include <linux/kernel_stat.h> |
| 14 | #include <linux/tick.h> |
| 15 | #include <linux/types.h> |
| 16 | /* |
| 17 | * Code picked from earlier governer implementations |
| 18 | */ |
| 19 | static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall) |
| 20 | { |
| 21 | u64 idle_time; |
| 22 | u64 cur_wall_time; |
| 23 | u64 busy_time; |
| 24 | |
| 25 | cur_wall_time = jiffies64_to_cputime64(get_jiffies_64()); |
| 26 | |
| 27 | busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER]; |
| 28 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM]; |
| 29 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ]; |
| 30 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ]; |
| 31 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL]; |
| 32 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE]; |
| 33 | |
| 34 | idle_time = cur_wall_time - busy_time; |
| 35 | if (wall) |
| 36 | *wall = jiffies_to_usecs(cur_wall_time); |
| 37 | |
| 38 | return jiffies_to_usecs(idle_time); |
| 39 | } |
| 40 | |
| 41 | cputime64_t get_cpu_idle_time(unsigned int cpu, cputime64_t *wall) |
| 42 | { |
| 43 | u64 idle_time = get_cpu_idle_time_us(cpu, NULL); |
| 44 | |
| 45 | if (idle_time == -1ULL) |
| 46 | return get_cpu_idle_time_jiffy(cpu, wall); |
| 47 | else |
| 48 | idle_time += get_cpu_iowait_time_us(cpu, wall); |
| 49 | |
| 50 | return idle_time; |
| 51 | } |
| 52 | EXPORT_SYMBOL_GPL(get_cpu_idle_time); |