Merge "Revert "Mark HI and TASKLET softirq synchronous""

kernel/irq/cpuhotplug.c

@@ -116,6 +116,8 @@ static bool migrate_one_irq(struct irq_desc *desc)
 	affinity = &available_cpus;
 
 	if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
+		const struct cpumask *default_affinity;
+
 		/*
 		 * If the interrupt is managed, then shut it down and leave
 		 * the affinity untouched.
@@ -125,6 +127,8 @@ static bool migrate_one_irq(struct irq_desc *desc)
 			irq_shutdown_and_deactivate(desc);
 			return false;
 		}
+
+		default_affinity = desc->affinity_hint ? : irq_default_affinity;
 		/*
 		 * The order of preference for selecting a fallback CPU is
 		 *
@@ -134,9 +138,9 @@ static bool migrate_one_irq(struct irq_desc *desc)
 		 */
 		cpumask_andnot(&available_cpus, cpu_online_mask,
 							cpu_isolated_mask);
-		if (cpumask_intersects(&available_cpus, irq_default_affinity))
+		if (cpumask_intersects(&available_cpus, default_affinity))
 			cpumask_and(&available_cpus, &available_cpus,
-							irq_default_affinity);
+							default_affinity);
 		else if (cpumask_empty(&available_cpus))
 			affinity = cpu_online_mask;
 

kernel/sched/cpupri.c

@@ -122,6 +122,8 @@ retry:
 
 		if (lowest_mask) {
 			cpumask_and(lowest_mask, p->cpus_ptr, vec->mask);
+			cpumask_andnot(lowest_mask, lowest_mask,
+				       cpu_isolated_mask);
 			if (drop_nopreempts)
 				drop_nopreempt_cpus(lowest_mask);
 			/*

kernel/softirq.c

@@ -85,16 +85,12 @@ static void wakeup_softirqd(void)
 
 /*
  * If ksoftirqd is scheduled, we do not want to process pending softirqs
- * right now. Let ksoftirqd handle this at its own rate, to get fairness,
- * unless we're doing some of the synchronous softirqs.
+ * right now. Let ksoftirqd handle this at its own rate, to get fairness.
  */
-#define SOFTIRQ_NOW_MASK ((1 << HI_SOFTIRQ) | (1 << TASKLET_SOFTIRQ))
-static bool ksoftirqd_running(unsigned long pending)
+static bool ksoftirqd_running(void)
 {
 	struct task_struct *tsk = __this_cpu_read(ksoftirqd);
 
-	if (pending & SOFTIRQ_NOW_MASK)
-		return false;
 	return tsk && (tsk->state == TASK_RUNNING) &&
 		!__kthread_should_park(tsk);
 }
@@ -253,8 +249,16 @@ static inline bool lockdep_softirq_start(void) { return false; }
 static inline void lockdep_softirq_end(bool in_hardirq) { }
 #endif
 
-#define long_softirq_pending()	(local_softirq_pending() & LONG_SOFTIRQ_MASK)
-#define defer_for_rt()		(long_softirq_pending() && cpupri_check_rt())
+#define softirq_deferred_for_rt(pending)		\
+({							\
+	__u32 deferred = 0;				\
+	if (cpupri_check_rt()) {			\
+		deferred = pending & LONG_SOFTIRQ_MASK; \
+		pending &= ~LONG_SOFTIRQ_MASK;		\
+	}						\
+	deferred;					\
+})
+
 asmlinkage __visible void __softirq_entry __do_softirq(void)
 {
 	unsigned long end = jiffies + MAX_SOFTIRQ_TIME;
@@ -262,6 +266,7 @@ asmlinkage __visible void __softirq_entry __do_softirq(void)
 	int max_restart = MAX_SOFTIRQ_RESTART;
 	struct softirq_action *h;
 	bool in_hardirq;
+	__u32 deferred;
 	__u32 pending;
 	int softirq_bit;
 
@@ -273,14 +278,14 @@ asmlinkage __visible void __softirq_entry __do_softirq(void)
 	current->flags &= ~PF_MEMALLOC;
 
 	pending = local_softirq_pending();
+	deferred = softirq_deferred_for_rt(pending);
 	account_irq_enter_time(current);
-
 	__local_bh_disable_ip(_RET_IP_, SOFTIRQ_OFFSET);
 	in_hardirq = lockdep_softirq_start();
 
 restart:
 	/* Reset the pending bitmask before enabling irqs */
-	set_softirq_pending(0);
+	set_softirq_pending(deferred);
 	__this_cpu_write(active_softirqs, pending);
 
 	local_irq_enable();
@@ -317,15 +322,16 @@ restart:
 	local_irq_disable();
 
 	pending = local_softirq_pending();
+	deferred = softirq_deferred_for_rt(pending);
+
 	if (pending) {
 		if (time_before(jiffies, end) && !need_resched() &&
-		    !defer_for_rt() &&
 		    --max_restart)
 			goto restart;
-
-		wakeup_softirqd();
 	}
 
+	if (pending | deferred)
+		wakeup_softirqd();
 	lockdep_softirq_end(in_hardirq);
 	account_irq_exit_time(current);
 	__local_bh_enable(SOFTIRQ_OFFSET);
@@ -345,7 +351,7 @@ asmlinkage __visible void do_softirq(void)
 
 	pending = local_softirq_pending();
 
-	if (pending && !ksoftirqd_running(pending))
+	if (pending && !ksoftirqd_running())
 		do_softirq_own_stack();
 
 	local_irq_restore(flags);
@@ -372,10 +378,10 @@ void irq_enter(void)
 
 static inline void invoke_softirq(void)
 {
-	if (ksoftirqd_running(local_softirq_pending()))
+	if (ksoftirqd_running())
 		return;
 
-	if (!force_irqthreads && !defer_for_rt()) {
+	if (!force_irqthreads) {
 #ifdef CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK
 		/*
 		 * We can safely execute softirq on the current stack if