From e1c805309d19c69d4ebeac38724076fa86feacdf Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Thu, 23 Apr 2009 13:58:08 +0200 Subject: [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 ++++++++++++++++ 2 files changed, 20 insertions(+) (limited to 'arch/s390') diff --git a/arch/s390/include/asm/cputime.h b/arch/s390/include/asm/cputime.h index 95b0f7db3c6..941384fbd39 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 38ea92ff04f..c87f59bd824 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. -- cgit v1.2.3