Linux 3.10.44-rt46-rc1

Dear RT Folks,

This is the RT stable review cycle of patch 3.10.44-rt46-rc1.

Please scream at me if I messed something up. Please test the patches too.

The -rc release will be uploaded to kernel.org and will be deleted when the final release is out. This is just a review release (or release candidate).

The pre-releases will not be pushed to the git repository, only the final release is.

If all goes well, this patch will be converted to the next main release on 7/7/2014.

Enjoy,

-- Steve

To build 3.10.44-rt46-rc1 directly, the following patches should be applied:

http://www.kernel.org/pub/linux/kernel/v3.x/linux-3.10.tar.xz

http://www.kernel.org/pub/linux/kernel/v3.x/patch-3.10.44.xz

http://www.kernel.org/pub/linux/kernel/projects/rt/3.10/patch-3.10.44-rt46-rc1.patch.xz

You can also build from 3.10.44-rt45 by applying the incremental patch:

http://www.kernel.org/pub/linux/kernel/projects/rt/3.10/incr/patch-3.10.44-rt45-rt46-rc1.patch.xz

Changes from 3.10.44-rt45:

---

Ben Hutchings (1):
Fix latency histogram after "hrtimer: Set expiry time before switch_hrtimer_base()"

Sebastian Andrzej Siewior (1):
timer: do not spin_trylock() on UP

Steven Rostedt (Red Hat) (1):

      Linux 3.10.44-rt46-rc1

----

 kernel/hrtimer.c | 10 +++++-----
 kernel/timer.c   | 13 +++++++++++++
 localversion-rt  |  2 +-
 3 files changed, 19 insertions(+), 6 deletions(-)

3.10.44-rt46-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Sebastian Andrzej Siewior <[email protected]>

This will void a warning comming from the spin-lock debugging code. The lock avoiding idea is from Steven Rostedt.

---
 kernel/timer.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

index 26cca8b924e7..40cfa14131ca 100644
@@ -1461,6 +1461,19 @@ void run_local_timers(void)
 	 * the timer softirq.
 	 */
 #ifdef CONFIG_PREEMPT_RT_FULL
+
+#ifndef CONFIG_SMP
+	/*
+	 * The spin_do_trylock() later may fail as the lock may be hold before
+	 * the interrupt arrived. The spin-lock debugging code will raise a
+	 * warning if the try_lock fails on UP. Since this is only an
+	 * optimization for the FULL_NO_HZ case (not to run the timer softirq on
+	 * an nohz_full CPU) we don't really care and shedule the softirq.
+	 */
+	raise_softirq(TIMER_SOFTIRQ);
+	return;
+#endif
+
 	/* On RT, irq work runs from softirq */
 	if (irq_work_needs_cpu()) {
 		raise_softirq(TIMER_SOFTIRQ);

2.0.0

3.10.44-rt46-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Ben Hutchings <[email protected]>

In an rt-kernel with CONFIG_MISSED_TIMER_OFFSETS_HIST enabled, __hrtimer_start_range_ns() now crashes, as new_base is not assigned before it is used.

---
 kernel/hrtimer.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

index f7a3a7a5a61b..1defbda1def8 100644
@@ -1102,6 +1102,11 @@ int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
 #endif
 	}
 
+	hrtimer_set_expires_range_ns(timer, tim, delta_ns);
+
+	/* Switch the timer base, if necessary: */
+	new_base = switch_hrtimer_base(timer, base, mode & HRTIMER_MODE_PINNED);
+
 #ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
 	{
 		ktime_t now = new_base->get_time();

@@ -1113,11 +1118,6 @@ int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
 	}
 #endif
 
-	hrtimer_set_expires_range_ns(timer, tim, delta_ns);
-
-	/* Switch the timer base, if necessary: */
-	new_base = switch_hrtimer_base(timer, base, mode & HRTIMER_MODE_PINNED);

3.10.44-rt46-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: "Steven Rostedt (Red Hat)" <[email protected]>

---
 localversion-rt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index 38c40b21a885..2a08cf6d539b 100644
@@ -1 +1 @@
--rt45
+-rt46-rc1

2.0.0