patches/softirq-make-fifo.patch

Subject: softirq-make-fifo.patch
From: Thomas Gleixner <tglx@linutronix.de>
Date: Thu, 21 Jul 2011 21:06:43 +0200

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 kernel/softirq.c |   18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -364,6 +364,8 @@ asmlinkage void do_softirq(void)
 
 static inline void local_bh_disable_nort(void) { local_bh_disable(); }
 static inline void _local_bh_enable_nort(void) { _local_bh_enable(); }
+static void ksoftirqd_set_sched_params(unsigned int cpu) { }
+static void ksoftirqd_clr_sched_params(unsigned int cpu, bool online) { }
 
 #else /* !PREEMPT_RT_FULL */
 
@@ -518,6 +520,20 @@ static int ksoftirqd_do_softirq(int cpu)
 static inline void local_bh_disable_nort(void) { }
 static inline void _local_bh_enable_nort(void) { }
 
+static inline void ksoftirqd_set_sched_params(unsigned int cpu)
+{
+	struct sched_param param = { .sched_priority = 1 };
+
+	sched_setscheduler(current, SCHED_FIFO, &param);
+}
+
+static inline void ksoftirqd_clr_sched_params(unsigned int cpu, bool online)
+{
+	struct sched_param param = { .sched_priority = 0 };
+
+	sched_setscheduler(current, SCHED_NORMAL, &param);
+}
+
 #endif /* PREEMPT_RT_FULL */
 /*
  * Enter an interrupt context.
@@ -1065,6 +1081,8 @@ static struct notifier_block __cpuinitda
 
 static struct smp_hotplug_thread softirq_threads = {
 	.store			= &ksoftirqd,
+	.setup			= ksoftirqd_set_sched_params,
+	.cleanup		= ksoftirqd_clr_sched_params,
 	.thread_should_run	= ksoftirqd_should_run,
 	.thread_fn		= run_ksoftirqd,
 	.thread_comm		= "ksoftirqd/%u",