Re: [PATCH] rcu: Eliminate softirq processing from rcutree

[Mike Galbraith <bitbucket@online.de>]

On Wed, 2013-12-25 at 04:07 +0100, Mike Galbraith wrote:
> On Tue, 2013-12-24 at 11:36 -0800, Paul E. McKenney wrote: 

> > So which code do you think deserves the big lump of coal?  ;-)
> 
> Sebastian's NO_HZ_FULL locking fixes.

Whack-a-mole hasn't yet dug up any new moles.

---
 kernel/timer.c |    4 ++++
 1 file changed, 4 insertions(+)

Index: linux-2.6/kernel/timer.c
===================================================================
--- linux-2.6.orig/kernel/timer.c
+++ linux-2.6/kernel/timer.c
@@ -764,7 +764,9 @@ __mod_timer(struct timer_list *timer, un
 	timer_stats_timer_set_start_info(timer);
 	BUG_ON(!timer->function);
 
+	local_irq_disable_rt();
 	base = lock_timer_base(timer, &flags);
+	local_irq_enable_rt();
 
 	ret = detach_if_pending(timer, base, false);
 	if (!ret && pending_only)
@@ -1198,7 +1200,9 @@ static inline void __run_timers(struct t
 {
 	struct timer_list *timer;
 
+	local_irq_disable_rt();
 	spin_lock_irq(&base->lock);
+	local_irq_enable_rt();
 	while (time_after_eq(jiffies, base->timer_jiffies)) {
 		struct list_head work_list;
 		struct list_head *head = &work_list;
---
 kernel/time/tick-sched.c |    2 ++
 1 file changed, 2 insertions(+)

Index: linux-2.6/kernel/time/tick-sched.c
===================================================================
--- linux-2.6.orig/kernel/time/tick-sched.c
+++ linux-2.6/kernel/time/tick-sched.c
@@ -216,7 +216,9 @@ void __tick_nohz_full_check(void)
 
 static void nohz_full_kick_work_func(struct irq_work *work)
 {
+	local_irq_disable_rt();
 	__tick_nohz_full_check();
+	local_irq_enable_rt();
 }
 
 static DEFINE_PER_CPU(struct irq_work, nohz_full_kick_work) = {