X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=kernel%2Fsoftirq.c;h=36e0617400470f398700376c7fa3359d768e7e58;hb=8558f8f81680a43d383abd1b5f23d3501fedfa65;hp=bd89bc4eb0b9c0baa8070678d3cb099a8b40bb1c;hpb=37e58df30063e229ee5157f9d1c1fa1d749917c2;p=linux-2.6

diff --git a/kernel/softirq.c b/kernel/softirq.c
index bd89bc4eb0..36e0617400 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -3,7 +3,9 @@
  *
  *	Copyright (C) 1992 Linus Torvalds
  *
- * Rewritten. Old one was good in 2.2, but in 2.3 it was immoral. --ANK (990903)
+ *	Distribute under GPLv2.
+ *
+ *	Rewritten. Old one was good in 2.2, but in 2.3 it was immoral. --ANK (990903)
  */
 
 #include <linux/module.h>
@@ -278,9 +280,14 @@ asmlinkage void do_softirq(void)
  */
 void irq_enter(void)
 {
+#ifdef CONFIG_NO_HZ
+	int cpu = smp_processor_id();
+	if (idle_cpu(cpu) && !in_interrupt())
+		tick_nohz_stop_idle(cpu);
+#endif
 	__irq_enter();
 #ifdef CONFIG_NO_HZ
-	if (idle_cpu(smp_processor_id()))
+	if (idle_cpu(cpu))
 		tick_nohz_update_jiffies();
 #endif
 }
@@ -306,6 +313,7 @@ void irq_exit(void)
 	/* Make sure that timer wheel updates are propagated */
 	if (!in_interrupt() && idle_cpu(smp_processor_id()) && !need_resched())
 		tick_nohz_stop_sched_tick();
+	rcu_irq_exit();
 #endif
 	preempt_enable_no_resched();
 }
@@ -313,7 +321,7 @@ void irq_exit(void)
 /*
  * This function must run with irqs disabled!
  */
-inline fastcall void raise_softirq_irqoff(unsigned int nr)
+inline void raise_softirq_irqoff(unsigned int nr)
 {
 	__raise_softirq_irqoff(nr);
 
@@ -330,7 +338,7 @@ inline fastcall void raise_softirq_irqoff(unsigned int nr)
 		wakeup_softirqd();
 }
 
-void fastcall raise_softirq(unsigned int nr)
+void raise_softirq(unsigned int nr)
 {
 	unsigned long flags;
 
@@ -348,7 +356,8 @@ void open_softirq(int nr, void (*action)(struct softirq_action*), void *data)
 /* Tasklets */
 struct tasklet_head
 {
-	struct tasklet_struct *list;
+	struct tasklet_struct *head;
+	struct tasklet_struct **tail;
 };
 
 /* Some compilers disobey section attribute on statics when not
@@ -356,26 +365,28 @@ struct tasklet_head
 static DEFINE_PER_CPU(struct tasklet_head, tasklet_vec) = { NULL };
 static DEFINE_PER_CPU(struct tasklet_head, tasklet_hi_vec) = { NULL };
 
-void fastcall __tasklet_schedule(struct tasklet_struct *t)
+void __tasklet_schedule(struct tasklet_struct *t)
 {
 	unsigned long flags;
 
 	local_irq_save(flags);
-	t->next = __get_cpu_var(tasklet_vec).list;
-	__get_cpu_var(tasklet_vec).list = t;
+	t->next = NULL;
+	*__get_cpu_var(tasklet_vec).tail = t;
+	__get_cpu_var(tasklet_vec).tail = &(t->next);
 	raise_softirq_irqoff(TASKLET_SOFTIRQ);
 	local_irq_restore(flags);
 }
 
 EXPORT_SYMBOL(__tasklet_schedule);
 
-void fastcall __tasklet_hi_schedule(struct tasklet_struct *t)
+void __tasklet_hi_schedule(struct tasklet_struct *t)
 {
 	unsigned long flags;
 
 	local_irq_save(flags);
-	t->next = __get_cpu_var(tasklet_hi_vec).list;
-	__get_cpu_var(tasklet_hi_vec).list = t;
+	t->next = NULL;
+	*__get_cpu_var(tasklet_hi_vec).tail = t;
+	__get_cpu_var(tasklet_hi_vec).tail = &(t->next);
 	raise_softirq_irqoff(HI_SOFTIRQ);
 	local_irq_restore(flags);
 }
@@ -387,8 +398,9 @@ static void tasklet_action(struct softirq_action *a)
 	struct tasklet_struct *list;
 
 	local_irq_disable();
-	list = __get_cpu_var(tasklet_vec).list;
-	__get_cpu_var(tasklet_vec).list = NULL;
+	list = __get_cpu_var(tasklet_vec).head;
+	__get_cpu_var(tasklet_vec).head = NULL;
+	__get_cpu_var(tasklet_vec).tail = &__get_cpu_var(tasklet_vec).head;
 	local_irq_enable();
 
 	while (list) {
@@ -408,8 +420,9 @@ static void tasklet_action(struct softirq_action *a)
 		}
 
 		local_irq_disable();
-		t->next = __get_cpu_var(tasklet_vec).list;
-		__get_cpu_var(tasklet_vec).list = t;
+		t->next = NULL;
+		*__get_cpu_var(tasklet_vec).tail = t;
+		__get_cpu_var(tasklet_vec).tail = &(t->next);
 		__raise_softirq_irqoff(TASKLET_SOFTIRQ);
 		local_irq_enable();
 	}
@@ -420,8 +433,9 @@ static void tasklet_hi_action(struct softirq_action *a)
 	struct tasklet_struct *list;
 
 	local_irq_disable();
-	list = __get_cpu_var(tasklet_hi_vec).list;
-	__get_cpu_var(tasklet_hi_vec).list = NULL;
+	list = __get_cpu_var(tasklet_hi_vec).head;
+	__get_cpu_var(tasklet_hi_vec).head = NULL;
+	__get_cpu_var(tasklet_hi_vec).tail = &__get_cpu_var(tasklet_hi_vec).head;
 	local_irq_enable();
 
 	while (list) {
@@ -441,8 +455,9 @@ static void tasklet_hi_action(struct softirq_action *a)
 		}
 
 		local_irq_disable();
-		t->next = __get_cpu_var(tasklet_hi_vec).list;
-		__get_cpu_var(tasklet_hi_vec).list = t;
+		t->next = NULL;
+		*__get_cpu_var(tasklet_hi_vec).tail = t;
+		__get_cpu_var(tasklet_hi_vec).tail = &(t->next);
 		__raise_softirq_irqoff(HI_SOFTIRQ);
 		local_irq_enable();
 	}
@@ -479,6 +494,15 @@ EXPORT_SYMBOL(tasklet_kill);
 
 void __init softirq_init(void)
 {
+	int cpu;
+
+	for_each_possible_cpu(cpu) {
+		per_cpu(tasklet_vec, cpu).tail =
+			&per_cpu(tasklet_vec, cpu).head;
+		per_cpu(tasklet_hi_vec, cpu).tail =
+			&per_cpu(tasklet_hi_vec, cpu).head;
+	}
+
 	open_softirq(TASKLET_SOFTIRQ, tasklet_action, NULL);
 	open_softirq(HI_SOFTIRQ, tasklet_hi_action, NULL);
 }
@@ -547,9 +571,12 @@ void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu)
 		return;
 
 	/* CPU is dead, so no lock needed. */
-	for (i = &per_cpu(tasklet_vec, cpu).list; *i; i = &(*i)->next) {
+	for (i = &per_cpu(tasklet_vec, cpu).head; *i; i = &(*i)->next) {
 		if (*i == t) {
 			*i = t->next;
+			/* If this was the tail element, move the tail ptr */
+			if (*i == NULL)
+				per_cpu(tasklet_vec, cpu).tail = i;
 			return;
 		}
 	}
@@ -558,20 +585,24 @@ void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu)
 
 static void takeover_tasklets(unsigned int cpu)
 {
-	struct tasklet_struct **i;
-
 	/* CPU is dead, so no lock needed. */
 	local_irq_disable();
 
 	/* Find end, append list for that CPU. */
-	for (i = &__get_cpu_var(tasklet_vec).list; *i; i = &(*i)->next);
-	*i = per_cpu(tasklet_vec, cpu).list;
-	per_cpu(tasklet_vec, cpu).list = NULL;
+	if (&per_cpu(tasklet_vec, cpu).head != per_cpu(tasklet_vec, cpu).tail) {
+		*(__get_cpu_var(tasklet_vec).tail) = per_cpu(tasklet_vec, cpu).head;
+		__get_cpu_var(tasklet_vec).tail = per_cpu(tasklet_vec, cpu).tail;
+		per_cpu(tasklet_vec, cpu).head = NULL;
+		per_cpu(tasklet_vec, cpu).tail = &per_cpu(tasklet_vec, cpu).head;
+	}
 	raise_softirq_irqoff(TASKLET_SOFTIRQ);
 
-	for (i = &__get_cpu_var(tasklet_hi_vec).list; *i; i = &(*i)->next);
-	*i = per_cpu(tasklet_hi_vec, cpu).list;
-	per_cpu(tasklet_hi_vec, cpu).list = NULL;
+	if (&per_cpu(tasklet_hi_vec, cpu).head != per_cpu(tasklet_hi_vec, cpu).tail) {
+		*__get_cpu_var(tasklet_hi_vec).tail = per_cpu(tasklet_hi_vec, cpu).head;
+		__get_cpu_var(tasklet_hi_vec).tail = per_cpu(tasklet_hi_vec, cpu).tail;
+		per_cpu(tasklet_hi_vec, cpu).head = NULL;
+		per_cpu(tasklet_hi_vec, cpu).tail = &per_cpu(tasklet_hi_vec, cpu).head;
+	}
 	raise_softirq_irqoff(HI_SOFTIRQ);
 
 	local_irq_enable();