[PATCH 10/10] nohz: Disable the tick when irq resume in full dynticks CPU

Frederic Weisbecker
2013-04-22T19:00:55Z

Eventually try to disable tick on irq exit, now that the
fundamental infrastructure is in place.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
---
kernel/softirq.c | 19 ++++++++++++++-----
1 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/kernel/softirq.c b/kernel/softirq.c
index de15813..8b1446d 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -337,6 +337,19 @@ static inline void invoke_softirq(void)
}
}

+static inline void tick_irq_exit(void)
+{
+#ifdef CONFIG_NO_HZ_COMMON
+ int cpu = smp_processor_id();
+
+ /* Make sure that timer wheel updates are propagated */
+ if ((idle_cpu(cpu) && !need_resched()) || tick_nohz_full_cpu(cpu)) {
+ if (!in_interrupt())
+ tick_nohz_irq_exit();
+ }
+#endif
+}
+
/*
* Exit an interrupt context. Process softirqs if needed and possible:
*/
@@ -348,11 +361,7 @@ void irq_exit(void)
if (!in_interrupt() && local_softirq_pending())
invoke_softirq();

-#ifdef CONFIG_NO_HZ_COMMON
- /* Make sure that timer wheel updates are propagated */
- if (idle_cpu(smp_processor_id()) && !in_interrupt() && !need_resched())
- tick_nohz_irq_exit();
-#endif
+ tick_irq_exit();
rcu_irq_exit();
sched_preempt_enable_no_resched();
}
--
1.7.5.4