From fae8b22d3e3e3a3d317a7746493997af02a3f35c Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Mon, 22 Oct 2007 12:52:39 +0200 Subject: [PATCH] [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 Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/process.c | 16 ++++++++++ arch/s390/kernel/smp.c | 63 ++++++++++++++++++++++++++++++++++++-- include/asm-s390/cpu.h | 25 +++++++++++++++ 3 files changed, 101 insertions(+), 3 deletions(-) create mode 100644 include/asm-s390/cpu.h diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c index 70c57378f426..cc7c4ba0774d 100644 --- a/arch/s390/kernel/process.c +++ b/arch/s390/kernel/process.c @@ -44,6 +44,7 @@ #include #include #include +#include asmlinkage void ret_from_fork(void) asm ("ret_from_fork"); @@ -91,6 +92,14 @@ EXPORT_SYMBOL(unregister_idle_notifier); 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 @@ extern void s390_handle_mcck(void); 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 @@ static void default_idle(void) 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 | diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c index 35edbef1d222..ba3fff06fad1 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -42,6 +42,7 @@ #include #include #include +#include /* * An array with a pointer the lowcore of every CPU. @@ -494,6 +495,8 @@ int __cpuinit start_secondary(void *cpuvoid) return 0; } +DEFINE_PER_CPU(struct s390_idle_data, s390_idle); + static void __init smp_create_idle(unsigned int cpu) { struct task_struct *p; @@ -506,6 +509,7 @@ static void __init smp_create_idle(unsigned int cpu) if (IS_ERR(p)) panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p)); current_set[cpu] = p; + spin_lock_init(&(&per_cpu(s390_idle, cpu))->lock); } static int cpu_stopped(int cpu) @@ -724,6 +728,7 @@ void __init smp_prepare_boot_cpu(void) cpu_set(0, cpu_online_map); S390_lowcore.percpu_offset = __per_cpu_offset[0]; current_set[0] = current; + spin_lock_init(&(&__get_cpu_var(s390_idle))->lock); } void __init smp_cpus_done(unsigned int max_cpus) @@ -756,22 +761,71 @@ static ssize_t show_capability(struct sys_device *dev, char *buf) } static SYSDEV_ATTR(capability, 0444, show_capability, NULL); +static ssize_t show_idle_count(struct sys_device *dev, char *buf) +{ + struct s390_idle_data *idle; + unsigned long long idle_count; + + idle = &per_cpu(s390_idle, dev->id); + spin_lock_irq(&idle->lock); + idle_count = idle->idle_count; + spin_unlock_irq(&idle->lock); + return sprintf(buf, "%llu\n", idle_count); +} +static SYSDEV_ATTR(idle_count, 0444, show_idle_count, NULL); + +static ssize_t show_idle_time(struct sys_device *dev, char *buf) +{ + struct s390_idle_data *idle; + unsigned long long new_time; + + idle = &per_cpu(s390_idle, dev->id); + spin_lock_irq(&idle->lock); + if (idle->in_idle) { + new_time = get_clock(); + idle->idle_time += new_time - idle->idle_enter; + idle->idle_enter = new_time; + } + new_time = idle->idle_time; + spin_unlock_irq(&idle->lock); + return sprintf(buf, "%llu us\n", new_time >> 12); +} +static SYSDEV_ATTR(idle_time, 0444, show_idle_time, NULL); + +static struct attribute *cpu_attrs[] = { + &attr_capability.attr, + &attr_idle_count.attr, + &attr_idle_time.attr, + NULL, +}; + +static struct attribute_group cpu_attr_group = { + .attrs = cpu_attrs, +}; + static int __cpuinit smp_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) { unsigned int cpu = (unsigned int)(long)hcpu; struct cpu *c = &per_cpu(cpu_devices, cpu); struct sys_device *s = &c->sysdev; + struct s390_idle_data *idle; switch (action) { case CPU_ONLINE: case CPU_ONLINE_FROZEN: - if (sysdev_create_file(s, &attr_capability)) + idle = &per_cpu(s390_idle, cpu); + spin_lock_irq(&idle->lock); + idle->idle_enter = 0; + idle->idle_time = 0; + idle->idle_count = 0; + spin_unlock_irq(&idle->lock); + if (sysfs_create_group(&s->kobj, &cpu_attr_group)) return NOTIFY_BAD; break; case CPU_DEAD: case CPU_DEAD_FROZEN: - sysdev_remove_file(s, &attr_capability); + sysfs_remove_group(&s->kobj, &cpu_attr_group); break; } return NOTIFY_OK; @@ -784,6 +838,7 @@ static struct notifier_block __cpuinitdata smp_cpu_nb = { static int __init topology_init(void) { int cpu; + int rc; register_cpu_notifier(&smp_cpu_nb); @@ -796,7 +851,9 @@ static int __init topology_init(void) if (!cpu_online(cpu)) continue; s = &c->sysdev; - sysdev_create_file(s, &attr_capability); + rc = sysfs_create_group(&s->kobj, &cpu_attr_group); + if (rc) + return rc; } return 0; } diff --git a/include/asm-s390/cpu.h b/include/asm-s390/cpu.h new file mode 100644 index 000000000000..352dde194f3c --- /dev/null +++ b/include/asm-s390/cpu.h @@ -0,0 +1,25 @@ +/* + * include/asm-s390/cpu.h + * + * Copyright IBM Corp. 2007 + * Author(s): Heiko Carstens + */ + +#ifndef _ASM_S390_CPU_H_ +#define _ASM_S390_CPU_H_ + +#include +#include +#include + +struct s390_idle_data { + spinlock_t lock; + unsigned int in_idle; + unsigned long long idle_count; + unsigned long long idle_enter; + unsigned long long idle_time; +}; + +DECLARE_PER_CPU(struct s390_idle_data, s390_idle); + +#endif /* _ASM_S390_CPU_H_ */ -- GitLab