Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer fixes from Thomas Gleixner:
 "The itimer removal one is not strictly a fix, but I really wanted to
  avoid a rebase of the urgent ones."

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Revert "clocksource: Load the ACPI PM clocksource asynchronously"
  clockevents: tTack broadcast device mode change in tick_broadcast_switch_to_oneshot()
  itimer: Use printk_once instead of WARN_ONCE
  nohz: Fix stale jiffies update in tick_nohz_restart()
  tick: Document TICK_ONESHOT config option
  proc: stats: Use arch_idle_time for idle and iowait times if available
  itimer: Schedule silent NULL pointer fixup in setitimer() for removal

1 files changed, 28 insertions, 6 deletions

diff --git a/fs/proc/stat.c b/fs/proc/stat.c
index 6a0c62d6e442..64c3b3172367 100644
--- a/fs/proc/stat.c
+++ b/fs/proc/stat.c
@@ -18,19 +18,39 @@
 #ifndef arch_irq_stat
 #define arch_irq_stat() 0
 #endif
-#ifndef arch_idle_time
-#define arch_idle_time(cpu) 0
-#endif
+
+#ifdef arch_idle_time
+
+static cputime64_t get_idle_time(int cpu)
+{
+        cputime64_t idle;
+
+        idle = kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE];
+        if (cpu_online(cpu) && !nr_iowait_cpu(cpu))
+                idle += arch_idle_time(cpu);
+        return idle;
+}
+
+static cputime64_t get_iowait_time(int cpu)
+{
+        cputime64_t iowait;
+
+        iowait = kcpustat_cpu(cpu).cpustat[CPUTIME_IOWAIT];
+        if (cpu_online(cpu) && nr_iowait_cpu(cpu))
+                iowait += arch_idle_time(cpu);
+        return iowait;
+}
+
+#else
 
 static u64 get_idle_time(int cpu)
 {
         u64 idle, idle_time = get_cpu_idle_time_us(cpu, NULL);
 
-        if (idle_time == -1ULL) {
+        if (idle_time == -1ULL)
                 /* !NO_HZ so we can rely on cpustat.idle */
                 idle = kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE];
-                idle += arch_idle_time(cpu);
-        } else
+        else
                 idle = usecs_to_cputime64(idle_time);
 
         return idle;
@@ -49,6 +69,8 @@ static u64 get_iowait_time(int cpu)
         return iowait;
 }
 
+#endif
+
 static int show_stat(struct seq_file *p, void *v)
 {
         int i, j;