softirq-add-more-debug.patch

Subject: softirq: Add more debugging
From: Thomas Gleixner <tglx@linutronix.de>
Date: Sun, 28 Oct 2012 15:21:59 +0000

We really want to find code which calls __raise_softirq_irqsoff() and
runs neither in hardirq context nor in a local_bh disabled
region. This is even wrong on mainline as that code relies on random
events to take care of it's newly raised softirq.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 kernel/softirq.c |   16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

Index: linux-stable/kernel/softirq.c
===================================================================
--- linux-stable.orig/kernel/softirq.c
+++ linux-stable/kernel/softirq.c
@@ -618,7 +618,7 @@ void thread_do_softirq(void)
 	}
 }
 
-void __raise_softirq_irqoff(unsigned int nr)
+static void do_raise_softirq_irqoff(unsigned int nr)
 {
 	trace_softirq_raise(nr);
 	or_softirq_pending(1UL << nr);
@@ -635,12 +635,19 @@ void __raise_softirq_irqoff(unsigned int
 		__this_cpu_read(ksoftirqd)->softirqs_raised |= (1U << nr);
 }
 
+void __raise_softirq_irqoff(unsigned int nr)
+{
+	do_raise_softirq_irqoff(nr);
+	if (!in_irq() && !current->softirq_nestcnt)
+		wakeup_softirqd();
+}
+
 /*
  * This function must run with irqs disabled!
  */
 void raise_softirq_irqoff(unsigned int nr)
 {
-	__raise_softirq_irqoff(nr);
+	do_raise_softirq_irqoff(nr);
 
 	/*
 	 * If we're in an hard interrupt we let irq return code deal
@@ -662,11 +669,6 @@ void raise_softirq_irqoff(unsigned int n
 		wakeup_softirqd();
 }
 
-void do_raise_softirq_irqoff(unsigned int nr)
-{
-	raise_softirq_irqoff(nr);
-}
-
 static inline int ksoftirqd_softirq_pending(void)
 {
 	return current->softirqs_raised;