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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2009-04-23 13:58:08 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2009-04-23 13:58:17 +0200
commite1c805309d19c69d4ebeac38724076fa86feacdf (patch)
tree73886783aac7c489a29f3e5eec56cbc2371a12dd /arch
parentb1ad171efa089ae26aba750d747d8149a4f860d5 (diff)
[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 <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/s390/include/asm/cputime.h4
-rw-r--r--arch/s390/kernel/vtime.c16
2 files changed, 20 insertions, 0 deletions
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.