From e1c805309d19c69d4ebeac38724076fa86feacdf Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Thu, 23 Apr 2009 13:58:08 +0200 Subject: [PATCH] [S390] /proc/stat idle field for idle cpus The cpu idle field in the output of /proc/stat is too small for cpus that have been idle for more than a tick. Add the architecture hook arch_idle_time that allows to add the not accounted idle time of a sleeping cpu without waking the cpu. The s390 implementation of arch_idle_time uses the already existing s390_idle_data per_cpu variable to find the sleep time of a neighboring idle cpu. Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/cputime.h | 4 ++++ arch/s390/kernel/vtime.c | 16 ++++++++++++++++ fs/proc/stat.c | 5 +++++ 3 files changed, 25 insertions(+) diff --git a/arch/s390/include/asm/cputime.h b/arch/s390/include/asm/cputime.h index 95b0f7db3c69..941384fbd39c 100644 --- a/arch/s390/include/asm/cputime.h +++ b/arch/s390/include/asm/cputime.h @@ -174,4 +174,8 @@ cputime64_to_clock_t(cputime64_t cputime) return __div(cputime, 4096000000ULL / USER_HZ); } +cputime64_t s390_get_idle_time(int cpu); + +#define arch_idle_time(cpu) s390_get_idle_time(cpu) + #endif /* _S390_CPUTIME_H */ diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c index 38ea92ff04f9..c87f59bd8246 100644 --- a/arch/s390/kernel/vtime.c +++ b/arch/s390/kernel/vtime.c @@ -240,6 +240,22 @@ void vtime_stop_cpu(void) } } +cputime64_t s390_get_idle_time(int cpu) +{ + struct s390_idle_data *idle; + unsigned long long now, idle_time, idle_enter; + + idle = &per_cpu(s390_idle, cpu); + spin_lock(&idle->lock); + now = get_clock(); + idle_time = 0; + idle_enter = idle->idle_enter; + if (idle_enter != 0ULL && idle_enter < now) + idle_time = now - idle_enter; + spin_unlock(&idle->lock); + return idle_time; +} + /* * Sorted add to a list. List is linear searched until first bigger * element is found. diff --git a/fs/proc/stat.c b/fs/proc/stat.c index f75efa22df5e..81e4eb60972e 100644 --- a/fs/proc/stat.c +++ b/fs/proc/stat.c @@ -18,6 +18,9 @@ #ifndef arch_irq_stat #define arch_irq_stat() 0 #endif +#ifndef arch_idle_time +#define arch_idle_time(cpu) 0 +#endif static int show_stat(struct seq_file *p, void *v) { @@ -40,6 +43,7 @@ static int show_stat(struct seq_file *p, void *v) nice = cputime64_add(nice, kstat_cpu(i).cpustat.nice); system = cputime64_add(system, kstat_cpu(i).cpustat.system); idle = cputime64_add(idle, kstat_cpu(i).cpustat.idle); + idle = cputime64_add(idle, arch_idle_time(i)); iowait = cputime64_add(iowait, kstat_cpu(i).cpustat.iowait); irq = cputime64_add(irq, kstat_cpu(i).cpustat.irq); softirq = cputime64_add(softirq, kstat_cpu(i).cpustat.softirq); @@ -69,6 +73,7 @@ static int show_stat(struct seq_file *p, void *v) nice = kstat_cpu(i).cpustat.nice; system = kstat_cpu(i).cpustat.system; idle = kstat_cpu(i).cpustat.idle; + idle = cputime64_add(idle, arch_idle_time(i)); iowait = kstat_cpu(i).cpustat.iowait; irq = kstat_cpu(i).cpustat.irq; softirq = kstat_cpu(i).cpustat.softirq;