*
* 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>
#include <linux/notifier.h>
#include <linux/percpu.h>
#include <linux/cpu.h>
+#include <linux/freezer.h>
#include <linux/kthread.h>
#include <linux/rcupdate.h>
#include <linux/smp.h>
+#include <linux/tick.h>
#include <asm/irq.h>
/*
}
/*
+ * 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)
+{
+ unsigned long flags;
+
+ WARN_ON_ONCE(in_irq());
+
+ raw_local_irq_save(flags);
+ add_preempt_count(SOFTIRQ_OFFSET);
+ /*
+ * Were softirqs turned off above:
+ */
+ if (softirq_count() == SOFTIRQ_OFFSET)
+ trace_softirqs_off(ip);
+ raw_local_irq_restore(flags);
+}
+#else /* !CONFIG_TRACE_IRQFLAGS */
+static inline void __local_bh_disable(unsigned long ip)
+{
+ add_preempt_count(SOFTIRQ_OFFSET);
+ barrier();
+}
+#endif /* CONFIG_TRACE_IRQFLAGS */
+
+void local_bh_disable(void)
+{
+ __local_bh_disable((unsigned long)__builtin_return_address(0));
+}
+
+EXPORT_SYMBOL(local_bh_disable);
+
+void __local_bh_enable(void)
+{
+ WARN_ON_ONCE(in_irq());
+
+ /*
+ * softirqs should never be enabled by __local_bh_enable(),
+ * it always nests inside local_bh_enable() sections:
+ */
+ WARN_ON_ONCE(softirq_count() == SOFTIRQ_OFFSET);
+
+ sub_preempt_count(SOFTIRQ_OFFSET);
+}
+EXPORT_SYMBOL_GPL(__local_bh_enable);
+
+/*
+ * Special-case - softirqs can safely be enabled in
+ * cond_resched_softirq(), or by __do_softirq(),
+ * without processing still-pending softirqs:
+ */
+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);
+}
+
+EXPORT_SYMBOL(_local_bh_enable);
+
+static inline void _local_bh_enable_ip(unsigned long ip)
+{
+ WARN_ON_ONCE(in_irq() || irqs_disabled());
+#ifdef CONFIG_TRACE_IRQFLAGS
+ local_irq_disable();
+#endif
+ /*
+ * Are softirqs going to be turned on now:
+ */
+ if (softirq_count() == SOFTIRQ_OFFSET)
+ trace_softirqs_on(ip);
+ /*
+ * Keep preemption disabled until we are done with
+ * softirq processing:
+ */
+ sub_preempt_count(SOFTIRQ_OFFSET - 1);
+
+ if (unlikely(!in_interrupt() && local_softirq_pending()))
+ do_softirq();
+
+ dec_preempt_count();
+#ifdef CONFIG_TRACE_IRQFLAGS
+ local_irq_enable();
+#endif
+ preempt_check_resched();
+}
+
+void local_bh_enable(void)
+{
+ _local_bh_enable_ip((unsigned long)__builtin_return_address(0));
+}
+EXPORT_SYMBOL(local_bh_enable);
+
+void local_bh_enable_ip(unsigned long ip)
+{
+ _local_bh_enable_ip(ip);
+}
+EXPORT_SYMBOL(local_bh_enable_ip);
+
+/*
* We restart softirq processing MAX_SOFTIRQ_RESTART times,
* and we fall back to softirqd after that.
*
int cpu;
pending = local_softirq_pending();
+ account_system_vtime(current);
+
+ __local_bh_disable((unsigned long)__builtin_return_address(0));
+ trace_softirq_enter();
- local_bh_disable();
cpu = smp_processor_id();
restart:
/* Reset the pending bitmask before enabling irqs */
if (pending)
wakeup_softirqd();
- __local_bh_enable();
+ trace_softirq_exit();
+
+ account_system_vtime(current);
+ _local_bh_enable();
}
#ifndef __ARCH_HAS_DO_SOFTIRQ
local_irq_restore(flags);
}
-EXPORT_SYMBOL(do_softirq);
-
#endif
-void local_bh_enable(void)
+/*
+ * Enter an interrupt context.
+ */
+void irq_enter(void)
{
- WARN_ON(irqs_disabled());
- /*
- * Keep preemption disabled until we are done with
- * softirq processing:
- */
- sub_preempt_count(SOFTIRQ_OFFSET - 1);
-
- if (unlikely(!in_interrupt() && local_softirq_pending()))
- do_softirq();
-
- dec_preempt_count();
- preempt_check_resched();
+#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(cpu))
+ tick_nohz_update_jiffies();
+#endif
}
-EXPORT_SYMBOL(local_bh_enable);
#ifdef __ARCH_IRQ_EXIT_IRQS_DISABLED
# define invoke_softirq() __do_softirq()
void irq_exit(void)
{
account_system_vtime(current);
+ trace_hardirq_exit();
sub_preempt_count(IRQ_EXIT_OFFSET);
if (!in_interrupt() && local_softirq_pending())
invoke_softirq();
+
+#ifdef CONFIG_NO_HZ
+ /* 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();
}
/*
* 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);
wakeup_softirqd();
}
-EXPORT_SYMBOL(raise_softirq_irqoff);
-
-void fastcall raise_softirq(unsigned int nr)
+void raise_softirq(unsigned int nr)
{
unsigned long flags;
local_irq_restore(flags);
}
-void open_softirq(int nr, void (*action)(struct softirq_action*), void *data)
+void open_softirq(int nr, void (*action)(struct softirq_action *))
{
- softirq_vec[nr].data = data;
softirq_vec[nr].action = action;
}
-EXPORT_SYMBOL(open_softirq);
-
/* 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
- initialized -- RR */
-static DEFINE_PER_CPU(struct tasklet_head, tasklet_vec) = { NULL };
-static DEFINE_PER_CPU(struct tasklet_head, tasklet_hi_vec) = { NULL };
+static DEFINE_PER_CPU(struct tasklet_head, tasklet_vec);
+static DEFINE_PER_CPU(struct tasklet_head, tasklet_hi_vec);
-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);
}
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) {
}
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();
}
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) {
}
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();
}
void __init softirq_init(void)
{
- open_softirq(TASKLET_SOFTIRQ, tasklet_action, NULL);
- open_softirq(HI_SOFTIRQ, tasklet_hi_action, NULL);
+ 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);
+ open_softirq(HI_SOFTIRQ, tasklet_hi_action);
}
static int ksoftirqd(void * __bind_cpu)
{
- set_user_nice(current, 19);
- current->flags |= PF_NOFREEZE;
-
set_current_state(TASK_INTERRUPTIBLE);
while (!kthread_should_stop()) {
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;
}
}
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();
}
#endif /* CONFIG_HOTPLUG_CPU */
-static int __devinit cpu_callback(struct notifier_block *nfb,
+static int __cpuinit cpu_callback(struct notifier_block *nfb,
unsigned long action,
void *hcpu)
{
switch (action) {
case CPU_UP_PREPARE:
- BUG_ON(per_cpu(tasklet_vec, hotcpu).list);
- BUG_ON(per_cpu(tasklet_hi_vec, hotcpu).list);
+ case CPU_UP_PREPARE_FROZEN:
p = kthread_create(ksoftirqd, hcpu, "ksoftirqd/%d", hotcpu);
if (IS_ERR(p)) {
printk("ksoftirqd for %i failed\n", hotcpu);
per_cpu(ksoftirqd, hotcpu) = p;
break;
case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
wake_up_process(per_cpu(ksoftirqd, hotcpu));
break;
#ifdef CONFIG_HOTPLUG_CPU
case CPU_UP_CANCELED:
+ case CPU_UP_CANCELED_FROZEN:
+ if (!per_cpu(ksoftirqd, hotcpu))
+ break;
/* Unbind so it can run. Fall thru. */
kthread_bind(per_cpu(ksoftirqd, hotcpu),
any_online_cpu(cpu_online_map));
case CPU_DEAD:
+ case CPU_DEAD_FROZEN: {
+ struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
+
p = per_cpu(ksoftirqd, hotcpu);
per_cpu(ksoftirqd, hotcpu) = NULL;
+ sched_setscheduler_nocheck(p, SCHED_FIFO, ¶m);
kthread_stop(p);
takeover_tasklets(hotcpu);
break;
+ }
#endif /* CONFIG_HOTPLUG_CPU */
}
return NOTIFY_OK;
}
-static struct notifier_block __devinitdata cpu_nfb = {
+static struct notifier_block __cpuinitdata cpu_nfb = {
.notifier_call = cpu_callback
};
__init int spawn_ksoftirqd(void)
{
void *cpu = (void *)(long)smp_processor_id();
- cpu_callback(&cpu_nfb, CPU_UP_PREPARE, cpu);
+ int err = cpu_callback(&cpu_nfb, CPU_UP_PREPARE, cpu);
+
+ BUG_ON(err == NOTIFY_BAD);
cpu_callback(&cpu_nfb, CPU_ONLINE, cpu);
register_cpu_notifier(&cpu_nfb);
return 0;
/*
* Call a function on all processors
*/
-int on_each_cpu(void (*func) (void *info), void *info, int retry, int wait)
+int on_each_cpu(void (*func) (void *info), void *info, int wait)
{
int ret = 0;
preempt_disable();
- ret = smp_call_function(func, info, retry, wait);
+ ret = smp_call_function(func, info, wait);
local_irq_disable();
func(info);
local_irq_enable();
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff