[S390] Add per-cpu idle time / idle count sysfs attributes.
Add two new sysfs entries per cpu: idle_count and idle_time.
idle_count contains the number of times a cpu went into idle state.
idle_time contains the time a cpu spent in idle state in microseconds.
This can be used e.g. by powertop to tell how often idle state is
entered and left.
# cat /sys/devices/system/cpu/cpu0/idle_count
504
# cat /sys/devices/system/cpu/cpu0/idle_time
469734037 us
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index 70c5737..cc7c4ba 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -44,6 +44,7 @@
#include <asm/processor.h>
#include <asm/irq.h>
#include <asm/timer.h>
+#include <asm/cpu.h>
asmlinkage void ret_from_fork(void) asm ("ret_from_fork");
@@ -91,6 +92,14 @@
void do_monitor_call(struct pt_regs *regs, long interruption_code)
{
+ struct s390_idle_data *idle;
+
+ idle = &__get_cpu_var(s390_idle);
+ spin_lock(&idle->lock);
+ idle->idle_time += get_clock() - idle->idle_enter;
+ idle->in_idle = 0;
+ spin_unlock(&idle->lock);
+
/* disable monitor call class 0 */
__ctl_clear_bit(8, 15);
@@ -105,6 +114,7 @@
static void default_idle(void)
{
int cpu, rc;
+ struct s390_idle_data *idle;
/* CPU is going idle. */
cpu = smp_processor_id();
@@ -142,6 +152,12 @@
return;
}
+ idle = &__get_cpu_var(s390_idle);
+ spin_lock(&idle->lock);
+ idle->idle_count++;
+ idle->in_idle = 1;
+ idle->idle_enter = get_clock();
+ spin_unlock(&idle->lock);
trace_hardirqs_on();
/* Wait for external, I/O or machine check interrupt. */
__load_psw_mask(psw_kernel_bits | PSW_MASK_WAIT |