* to the pending events, so lets the scheduler to balance
* the softirq load for us.
*/
-void wakeup_softirqd(void)
+static void wakeup_softirqd(void)
{
/* Interrupts are disabled: no need to stop preemption */
struct task_struct *tsk = __get_cpu_var(ksoftirqd);
}
/*
+ * preempt_count and SOFTIRQ_OFFSET usage:
+ * - preempt_count is changed by SOFTIRQ_OFFSET on entering or leaving
+ * softirq processing.
+ * - preempt_count is changed by SOFTIRQ_DISABLE_OFFSET (= 2 * SOFTIRQ_OFFSET)
+ * on local_bh_disable or local_bh_enable.
+ * This lets us distinguish between whether we are currently processing
+ * softirq and whether we just have bh disabled.
+ */
+
+/*
* This one is for softirq.c-internal use,
* where hardirqs are disabled legitimately:
*/
#ifdef CONFIG_TRACE_IRQFLAGS
-static void __local_bh_disable(unsigned long ip)
+static void __local_bh_disable(unsigned long ip, unsigned int cnt)
{
unsigned long flags;
* We must manually increment preempt_count here and manually
* call the trace_preempt_off later.
*/
- preempt_count() += SOFTIRQ_OFFSET;
+ preempt_count() += cnt;
/*
* Were softirqs turned off above:
*/
- if (softirq_count() == SOFTIRQ_OFFSET)
+ if (softirq_count() == cnt)
trace_softirqs_off(ip);
raw_local_irq_restore(flags);
- if (preempt_count() == SOFTIRQ_OFFSET)
+ if (preempt_count() == cnt)
trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
}
#else /* !CONFIG_TRACE_IRQFLAGS */
-static inline void __local_bh_disable(unsigned long ip)
+static inline void __local_bh_disable(unsigned long ip, unsigned int cnt)
{
- add_preempt_count(SOFTIRQ_OFFSET);
+ add_preempt_count(cnt);
barrier();
}
#endif /* CONFIG_TRACE_IRQFLAGS */
void local_bh_disable(void)
{
- __local_bh_disable((unsigned long)__builtin_return_address(0));
+ __local_bh_disable((unsigned long)__builtin_return_address(0),
+ SOFTIRQ_DISABLE_OFFSET);
}
EXPORT_SYMBOL(local_bh_disable);
+static void __local_bh_enable(unsigned int cnt)
+{
+ WARN_ON_ONCE(in_irq());
+ WARN_ON_ONCE(!irqs_disabled());
+
+ if (softirq_count() == cnt)
+ trace_softirqs_on((unsigned long)__builtin_return_address(0));
+ sub_preempt_count(cnt);
+}
+
/*
* Special-case - softirqs can safely be enabled in
* cond_resched_softirq(), or by __do_softirq(),
*/
void _local_bh_enable(void)
{
- WARN_ON_ONCE(in_irq());
- WARN_ON_ONCE(!irqs_disabled());
-
- if (softirq_count() == SOFTIRQ_OFFSET)
- trace_softirqs_on((unsigned long)__builtin_return_address(0));
- sub_preempt_count(SOFTIRQ_OFFSET);
+ __local_bh_enable(SOFTIRQ_DISABLE_OFFSET);
}
EXPORT_SYMBOL(_local_bh_enable);
/*
* Are softirqs going to be turned on now:
*/
- if (softirq_count() == SOFTIRQ_OFFSET)
+ if (softirq_count() == SOFTIRQ_DISABLE_OFFSET)
trace_softirqs_on(ip);
/*
* Keep preemption disabled until we are done with
* softirq processing:
*/
- sub_preempt_count(SOFTIRQ_OFFSET - 1);
+ sub_preempt_count(SOFTIRQ_DISABLE_OFFSET - 1);
if (unlikely(!in_interrupt() && local_softirq_pending()))
do_softirq();
pending = local_softirq_pending();
account_system_vtime(current);
- __local_bh_disable((unsigned long)__builtin_return_address(0));
+ __local_bh_disable((unsigned long)__builtin_return_address(0),
+ SOFTIRQ_OFFSET);
lockdep_softirq_enter();
cpu = smp_processor_id();
lockdep_softirq_exit();
account_system_vtime(current);
- _local_bh_enable();
+ __local_bh_enable(SOFTIRQ_OFFSET);
}
#ifndef __ARCH_HAS_DO_SOFTIRQ
rcu_irq_enter();
if (idle_cpu(cpu) && !in_interrupt()) {
- __irq_enter();
+ /*
+ * Prevent raise_softirq from needlessly waking up ksoftirqd
+ * here, as softirq will be serviced on return from interrupt.
+ */
+ local_bh_disable();
tick_check_idle(cpu);
- } else
- __irq_enter();
+ _local_bh_enable();
+ }
+
+ __irq_enter();
}
#ifdef __ARCH_IRQ_EXIT_IRQS_DISABLED
{
set_current_state(TASK_INTERRUPTIBLE);
+ current->flags |= PF_KSOFTIRQD;
while (!kthread_should_stop()) {
preempt_disable();
if (!local_softirq_pending()) {
return 0;
}
+#ifdef CONFIG_GENERIC_HARDIRQS
int __init __weak arch_probe_nr_irqs(void)
{
- return 0;
+ return NR_IRQS_LEGACY;
}
int __init __weak arch_early_irq_init(void)
{
return 0;
}
-
-int __weak arch_init_chip_data(struct irq_desc *desc, int node)
-{
- return 0;
-}
+#endif