linux/kernel/time/timer_list.c
Thomas Gleixner 398ca17fb5 hrtimer: Get rid of the resolution field in hrtimer_clock_base
The field has no value because all clock bases have the same
resolution. The resolution only changes when we switch to high
resolution timer mode. We can evaluate that from a single static
variable as well. In the !HIGHRES case its simply a constant.

Export the variable, so we can simplify the usage sites.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20150414203500.645454122@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:48 +02:00

404 lines
9.7 KiB
C

/*
* kernel/time/timer_list.c
*
* List pending timers
*
* Copyright(C) 2006, Red Hat, Inc., Ingo Molnar
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/proc_fs.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#include <linux/kallsyms.h>
#include <asm/uaccess.h>
#include "tick-internal.h"
struct timer_list_iter {
int cpu;
bool second_pass;
u64 now;
};
typedef void (*print_fn_t)(struct seq_file *m, unsigned int *classes);
DECLARE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases);
/*
* This allows printing both to /proc/timer_list and
* to the console (on SysRq-Q):
*/
__printf(2, 3)
static void SEQ_printf(struct seq_file *m, const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
if (m)
seq_vprintf(m, fmt, args);
else
vprintk(fmt, args);
va_end(args);
}
static void print_name_offset(struct seq_file *m, void *sym)
{
char symname[KSYM_NAME_LEN];
if (lookup_symbol_name((unsigned long)sym, symname) < 0)
SEQ_printf(m, "<%pK>", sym);
else
SEQ_printf(m, "%s", symname);
}
static void
print_timer(struct seq_file *m, struct hrtimer *taddr, struct hrtimer *timer,
int idx, u64 now)
{
#ifdef CONFIG_TIMER_STATS
char tmp[TASK_COMM_LEN + 1];
#endif
SEQ_printf(m, " #%d: ", idx);
print_name_offset(m, taddr);
SEQ_printf(m, ", ");
print_name_offset(m, timer->function);
SEQ_printf(m, ", S:%02lx", timer->state);
#ifdef CONFIG_TIMER_STATS
SEQ_printf(m, ", ");
print_name_offset(m, timer->start_site);
memcpy(tmp, timer->start_comm, TASK_COMM_LEN);
tmp[TASK_COMM_LEN] = 0;
SEQ_printf(m, ", %s/%d", tmp, timer->start_pid);
#endif
SEQ_printf(m, "\n");
SEQ_printf(m, " # expires at %Lu-%Lu nsecs [in %Ld to %Ld nsecs]\n",
(unsigned long long)ktime_to_ns(hrtimer_get_softexpires(timer)),
(unsigned long long)ktime_to_ns(hrtimer_get_expires(timer)),
(long long)(ktime_to_ns(hrtimer_get_softexpires(timer)) - now),
(long long)(ktime_to_ns(hrtimer_get_expires(timer)) - now));
}
static void
print_active_timers(struct seq_file *m, struct hrtimer_clock_base *base,
u64 now)
{
struct hrtimer *timer, tmp;
unsigned long next = 0, i;
struct timerqueue_node *curr;
unsigned long flags;
next_one:
i = 0;
raw_spin_lock_irqsave(&base->cpu_base->lock, flags);
curr = timerqueue_getnext(&base->active);
/*
* Crude but we have to do this O(N*N) thing, because
* we have to unlock the base when printing:
*/
while (curr && i < next) {
curr = timerqueue_iterate_next(curr);
i++;
}
if (curr) {
timer = container_of(curr, struct hrtimer, node);
tmp = *timer;
raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);
print_timer(m, timer, &tmp, i, now);
next++;
goto next_one;
}
raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);
}
static void
print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now)
{
SEQ_printf(m, " .base: %pK\n", base);
SEQ_printf(m, " .index: %d\n", base->index);
SEQ_printf(m, " .resolution: %u nsecs\n", (unsigned) hrtimer_resolution);
SEQ_printf(m, " .get_time: ");
print_name_offset(m, base->get_time);
SEQ_printf(m, "\n");
#ifdef CONFIG_HIGH_RES_TIMERS
SEQ_printf(m, " .offset: %Lu nsecs\n",
(unsigned long long) ktime_to_ns(base->offset));
#endif
SEQ_printf(m, "active timers:\n");
print_active_timers(m, base, now);
}
static void print_cpu(struct seq_file *m, int cpu, u64 now)
{
struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
int i;
SEQ_printf(m, "cpu: %d\n", cpu);
for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
SEQ_printf(m, " clock %d:\n", i);
print_base(m, cpu_base->clock_base + i, now);
}
#define P(x) \
SEQ_printf(m, " .%-15s: %Lu\n", #x, \
(unsigned long long)(cpu_base->x))
#define P_ns(x) \
SEQ_printf(m, " .%-15s: %Lu nsecs\n", #x, \
(unsigned long long)(ktime_to_ns(cpu_base->x)))
#ifdef CONFIG_HIGH_RES_TIMERS
P_ns(expires_next);
P(hres_active);
P(nr_events);
P(nr_retries);
P(nr_hangs);
P_ns(max_hang_time);
#endif
#undef P
#undef P_ns
#ifdef CONFIG_TICK_ONESHOT
# define P(x) \
SEQ_printf(m, " .%-15s: %Lu\n", #x, \
(unsigned long long)(ts->x))
# define P_ns(x) \
SEQ_printf(m, " .%-15s: %Lu nsecs\n", #x, \
(unsigned long long)(ktime_to_ns(ts->x)))
{
struct tick_sched *ts = tick_get_tick_sched(cpu);
P(nohz_mode);
P_ns(last_tick);
P(tick_stopped);
P(idle_jiffies);
P(idle_calls);
P(idle_sleeps);
P_ns(idle_entrytime);
P_ns(idle_waketime);
P_ns(idle_exittime);
P_ns(idle_sleeptime);
P_ns(iowait_sleeptime);
P(last_jiffies);
P(next_jiffies);
P_ns(idle_expires);
SEQ_printf(m, "jiffies: %Lu\n",
(unsigned long long)jiffies);
}
#endif
#undef P
#undef P_ns
SEQ_printf(m, "\n");
}
#ifdef CONFIG_GENERIC_CLOCKEVENTS
static void
print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu)
{
struct clock_event_device *dev = td->evtdev;
SEQ_printf(m, "Tick Device: mode: %d\n", td->mode);
if (cpu < 0)
SEQ_printf(m, "Broadcast device\n");
else
SEQ_printf(m, "Per CPU device: %d\n", cpu);
SEQ_printf(m, "Clock Event Device: ");
if (!dev) {
SEQ_printf(m, "<NULL>\n");
return;
}
SEQ_printf(m, "%s\n", dev->name);
SEQ_printf(m, " max_delta_ns: %llu\n",
(unsigned long long) dev->max_delta_ns);
SEQ_printf(m, " min_delta_ns: %llu\n",
(unsigned long long) dev->min_delta_ns);
SEQ_printf(m, " mult: %u\n", dev->mult);
SEQ_printf(m, " shift: %u\n", dev->shift);
SEQ_printf(m, " mode: %d\n", dev->mode);
SEQ_printf(m, " next_event: %Ld nsecs\n",
(unsigned long long) ktime_to_ns(dev->next_event));
SEQ_printf(m, " set_next_event: ");
print_name_offset(m, dev->set_next_event);
SEQ_printf(m, "\n");
if (dev->set_mode) {
SEQ_printf(m, " set_mode: ");
print_name_offset(m, dev->set_mode);
SEQ_printf(m, "\n");
} else {
if (dev->set_state_shutdown) {
SEQ_printf(m, " shutdown: ");
print_name_offset(m, dev->set_state_shutdown);
SEQ_printf(m, "\n");
}
if (dev->set_state_periodic) {
SEQ_printf(m, " periodic: ");
print_name_offset(m, dev->set_state_periodic);
SEQ_printf(m, "\n");
}
if (dev->set_state_oneshot) {
SEQ_printf(m, " oneshot: ");
print_name_offset(m, dev->set_state_oneshot);
SEQ_printf(m, "\n");
}
if (dev->tick_resume) {
SEQ_printf(m, " resume: ");
print_name_offset(m, dev->tick_resume);
SEQ_printf(m, "\n");
}
}
SEQ_printf(m, " event_handler: ");
print_name_offset(m, dev->event_handler);
SEQ_printf(m, "\n");
SEQ_printf(m, " retries: %lu\n", dev->retries);
SEQ_printf(m, "\n");
}
static void timer_list_show_tickdevices_header(struct seq_file *m)
{
#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
print_tickdevice(m, tick_get_broadcast_device(), -1);
SEQ_printf(m, "tick_broadcast_mask: %08lx\n",
cpumask_bits(tick_get_broadcast_mask())[0]);
#ifdef CONFIG_TICK_ONESHOT
SEQ_printf(m, "tick_broadcast_oneshot_mask: %08lx\n",
cpumask_bits(tick_get_broadcast_oneshot_mask())[0]);
#endif
SEQ_printf(m, "\n");
#endif
}
#endif
static inline void timer_list_header(struct seq_file *m, u64 now)
{
SEQ_printf(m, "Timer List Version: v0.7\n");
SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES);
SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now);
SEQ_printf(m, "\n");
}
static int timer_list_show(struct seq_file *m, void *v)
{
struct timer_list_iter *iter = v;
if (iter->cpu == -1 && !iter->second_pass)
timer_list_header(m, iter->now);
else if (!iter->second_pass)
print_cpu(m, iter->cpu, iter->now);
#ifdef CONFIG_GENERIC_CLOCKEVENTS
else if (iter->cpu == -1 && iter->second_pass)
timer_list_show_tickdevices_header(m);
else
print_tickdevice(m, tick_get_device(iter->cpu), iter->cpu);
#endif
return 0;
}
void sysrq_timer_list_show(void)
{
u64 now = ktime_to_ns(ktime_get());
int cpu;
timer_list_header(NULL, now);
for_each_online_cpu(cpu)
print_cpu(NULL, cpu, now);
#ifdef CONFIG_GENERIC_CLOCKEVENTS
timer_list_show_tickdevices_header(NULL);
for_each_online_cpu(cpu)
print_tickdevice(NULL, tick_get_device(cpu), cpu);
#endif
return;
}
static void *move_iter(struct timer_list_iter *iter, loff_t offset)
{
for (; offset; offset--) {
iter->cpu = cpumask_next(iter->cpu, cpu_online_mask);
if (iter->cpu >= nr_cpu_ids) {
#ifdef CONFIG_GENERIC_CLOCKEVENTS
if (!iter->second_pass) {
iter->cpu = -1;
iter->second_pass = true;
} else
return NULL;
#else
return NULL;
#endif
}
}
return iter;
}
static void *timer_list_start(struct seq_file *file, loff_t *offset)
{
struct timer_list_iter *iter = file->private;
if (!*offset)
iter->now = ktime_to_ns(ktime_get());
iter->cpu = -1;
iter->second_pass = false;
return move_iter(iter, *offset);
}
static void *timer_list_next(struct seq_file *file, void *v, loff_t *offset)
{
struct timer_list_iter *iter = file->private;
++*offset;
return move_iter(iter, 1);
}
static void timer_list_stop(struct seq_file *seq, void *v)
{
}
static const struct seq_operations timer_list_sops = {
.start = timer_list_start,
.next = timer_list_next,
.stop = timer_list_stop,
.show = timer_list_show,
};
static int timer_list_open(struct inode *inode, struct file *filp)
{
return seq_open_private(filp, &timer_list_sops,
sizeof(struct timer_list_iter));
}
static const struct file_operations timer_list_fops = {
.open = timer_list_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_private,
};
static int __init init_timer_list_procfs(void)
{
struct proc_dir_entry *pe;
pe = proc_create("timer_list", 0444, NULL, &timer_list_fops);
if (!pe)
return -ENOMEM;
return 0;
}
__initcall(init_timer_list_procfs);