s390_get_idle_time give us the duration from idle entry to now. But it does not tell us how to divide it to idle and iowait.
Modify this function to return 2 values. To realize this, s390's cputime accounting also requires timestamp at end of iowait. Not-Tested-by: Hidetoshi Seto <[email protected]> --- arch/s390/include/asm/cputime.h | 7 ++++- arch/s390/kernel/vtime.c | 40 ++++++++++++++++++++++++++++++++------ fs/proc/stat.c | 20 +++++++++++------- kernel/sched/core.c | 6 ++++- 4 files changed, 55 insertions(+), 18 deletions(-) diff --git a/arch/s390/include/asm/cputime.h b/arch/s390/include/asm/cputime.h index f65bd36..f4f882d 100644 --- a/arch/s390/include/asm/cputime.h +++ b/arch/s390/include/asm/cputime.h @@ -174,13 +174,16 @@ struct s390_idle_data { unsigned long long clock_idle_exit; unsigned long long timer_idle_enter; unsigned long long timer_idle_exit; + unsigned long long clock_iowait_exit; }; DECLARE_PER_CPU(struct s390_idle_data, s390_idle); -cputime64_t s390_get_idle_time(int cpu); +void s390_get_idle_and_iowait(int cpu, cputime64_t reti, cputime64_t retw); +void s390_record_iowait_exit(int cpu); -#define arch_idle_time(cpu) s390_get_idle_time(cpu) +#define arch_idle_and_iowait(cpu, i, w) s390_get_idle_and_iowait(cpu, i, w) +#define arch_record_iowait_exit(cpu) s390_save_iowait_exit(cpu) static inline int s390_nohz_delay(int cpu) { diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c index 8c34363..f945cbd 100644 --- a/arch/s390/kernel/vtime.c +++ b/arch/s390/kernel/vtime.c @@ -155,7 +155,7 @@ EXPORT_SYMBOL_GPL(vtime_account_system); void __kprobes vtime_stop_cpu(void) { struct s390_idle_data *idle = &__get_cpu_var(s390_idle); - unsigned long long idle_time; + unsigned long long idle_enter, idle_exit, iowait_exit; unsigned long psw_mask; trace_hardirqs_on(); @@ -171,19 +171,21 @@ void __kprobes vtime_stop_cpu(void) /* Account time spent with enabled wait psw loaded as idle time. */ idle->sequence++; smp_wmb(); - idle_time = idle->clock_idle_exit - idle->clock_idle_enter; + idle_enter = idle->clock_idle_enter; + idle_exit = idle->clock_idle_exit; + iowait_exit = idle->clock_iowait_exit; idle->clock_idle_enter = idle->clock_idle_exit = 0ULL; - idle->idle_time += idle_time; + idle->idle_time += idle_exit - idle_enter; idle->idle_count++; - account_idle_time(idle_time); + account_idle_and_iowait(idle_enter, iowait_exit, idle_exit); smp_wmb(); idle->sequence++; } -cputime64_t s390_get_idle_time(int cpu) +void s390_get_idle_and_iowait(int cpu, cputime64_t *reti, cputime64_t *retw) { struct s390_idle_data *idle = &per_cpu(s390_idle, cpu); - unsigned long long now, idle_enter, idle_exit; + unsigned long long now, idle_enter, idle_exit, iowait_exit; unsigned int sequence; do { @@ -191,8 +193,32 @@ cputime64_t s390_get_idle_time(int cpu) sequence = ACCESS_ONCE(idle->sequence); idle_enter = ACCESS_ONCE(idle->clock_idle_enter); idle_exit = ACCESS_ONCE(idle->clock_idle_exit); + iowait_exit = ACCESS_ONCE(idle->clock_iowait_exit); } while ((sequence & 1) || (ACCESS_ONCE(idle->sequence) != sequence)); - return idle_enter ? ((idle_exit ?: now) - idle_enter) : 0; + + if (!idle_enter) { + *reti = *retw = 0ULL; + } else { + if (!idle_exit) + idle_exit = now; + if (nr_iowait_cpu(cpu)) { + *retw = idle_exit - idle_enter; + *reti = 0ULL; + } else if (iowait_exit > idle_enter) { + *retw = iowait_exit - idle_enter; + *reti = idle_exit - iowait_exit; + } else { + *retw = 0ULL; + *reti = idle_exit - idle_enter; + } + } +} + +void s390_record_iowait_exit(int cpu) +{ + struct s390_idle_data *idle = &per_cpu(s390_idle, cpu); + + idle->clock_iowait_exit = get_tod_clock(); } /* diff --git a/fs/proc/stat.c b/fs/proc/stat.c index 9d231e9..6b23a89 100644 --- a/fs/proc/stat.c +++ b/fs/proc/stat.c @@ -19,25 +19,29 @@ #define arch_irq_stat() 0 #endif -#ifdef arch_idle_time +#ifdef arch_idle_and_iowait static cputime64_t get_idle_time(int cpu) { - cputime64_t idle; + cputime64_t idle, idle_not_accounted_yet, unused; idle = kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE]; - if (cpu_online(cpu) && !nr_iowait_cpu(cpu)) - idle += arch_idle_time(cpu); + if (cpu_online(cpu)) { + arch_idle_and_iowait(cpu, &idle_not_accounted_yet, &unused); + idle += idle_not_accounted_yet; + } return idle; } static cputime64_t get_iowait_time(int cpu) { - cputime64_t iowait; + cputime64_t iowait, iowait_not_accounted_yet, unused; iowait = kcpustat_cpu(cpu).cpustat[CPUTIME_IOWAIT]; - if (cpu_online(cpu) && nr_iowait_cpu(cpu)) - iowait += arch_idle_time(cpu); + if (cpu_online(cpu)) { + arch_idle_and_iowait(cpu, &unused, &iowait_not_accounted_yet); + iowait += iowait_not_accounted_yet; + } return iowait; } @@ -75,7 +79,7 @@ static u64 get_iowait_time(int cpu) return iowait; } -#endif +#endif /* arch_idle_and_iowait */ static int show_stat(struct seq_file *p, void *v) { diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 814ee2e..52abf79 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4344,8 +4344,12 @@ static inline void iowait_stop(struct rq *rq) current->in_iowait = 0; raw_spin_lock(&rq->iowait_lock); rq->nr_iowait--; - if (!rq->nr_iowait && rq != this_rq()) + if (!rq->nr_iowait && rq != this_rq()) { +#ifdef arch_record_iowait_exit + arch_record_iowait_exit(rq->cpu); +#endif rq->last_iowait = ktime_get(); + } raw_spin_unlock(&rq->iowait_lock); } -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
