Merge branch 'timers/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'timers/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: add PCI ID for 6300ESB force hpet
  x86: add another PCI ID for ICH6 force-hpet
  kernel-paramaters: document pmtmr= command line option
  acpi_pm clccksource: fix printk format warning
  nohz: don't stop idle tick if softirqs are pending.
  pmtmr: allow command line override of ioport
  nohz: reduce jiffies polling overhead
  hrtimer: Remove unused variables in ktime_divns()
  hrtimer: remove warning in hres_timers_resume
  posix-timers: print RT watchdog message

1 files changed, 8 insertions, 0 deletions

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index d63008b09a4c..beef7ccdf842 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -48,6 +48,13 @@ static void tick_do_update_jiffies64(ktime_t now)
         unsigned long ticks = 0;
         ktime_t delta;
 
+        /*
+         * Do a quick check without holding xtime_lock:
+         */
+        delta = ktime_sub(now, last_jiffies_update);
+        if (delta.tv64 < tick_period.tv64)
+                return;
+
         /* Reevalute with xtime_lock held */
         write_seqlock(&xtime_lock);
 
@@ -228,6 +235,7 @@ void tick_nohz_stop_sched_tick(void)
                                local_softirq_pending());
                         ratelimit++;
                 }
+                goto end;
         }
 
         ts->idle_calls++;