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

3 files changed, 13 insertions, 5 deletions

diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 27a83ee..2913a8b 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -300,11 +300,10 @@ EXPORT_SYMBOL_GPL(ktime_sub_ns);
  */
 u64 ktime_divns(const ktime_t kt, s64 div)
 {
-	u64 dclc, inc, dns;
+	u64 dclc;
 	int sft = 0;
 
-	dclc = dns = ktime_to_ns(kt);
-	inc = div;
+	dclc = ktime_to_ns(kt);
 	/* Make sure the divisor is less than 2^32: */
 	while (div >> 32) {
 		sft++;
@@ -632,8 +631,6 @@ void clock_was_set(void)
  */
 void hres_timers_resume(void)
 {
-	WARN_ON_ONCE(num_online_cpus() > 1);
-
 	/* Retrigger the CPU local events: */
 	retrigger_next_event(NULL);
 }
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index f1525ad..c42a03a 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -1037,6 +1037,9 @@ static void check_thread_timers(struct task_struct *tsk,
 				sig->rlim[RLIMIT_RTTIME].rlim_cur +=
 								USEC_PER_SEC;
 			}
+			printk(KERN_INFO
+				"RT Watchdog Timeout: %s[%d]\n",
+				tsk->comm, task_pid_nr(tsk));
 			__group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
 		}
 	}
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index d63008b..beef7cc 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++;