#include <linux/freezer.h>
#include <linux/kthread.h>
#include <linux/rcupdate.h>
+#include <linux/ftrace.h>
#include <linux/smp.h>
#include <linux/tick.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/irq.h>
+
#include <asm/irq.h>
/*
- No shared variables, all the data are CPU local.
static DEFINE_PER_CPU(struct task_struct *, ksoftirqd);
+char *softirq_to_name[NR_SOFTIRQS] = {
+ "HI", "TIMER", "NET_TX", "NET_RX", "BLOCK", "BLOCK_IOPOLL",
+ "TASKLET", "SCHED", "HRTIMER", "RCU"
+};
+
/*
* we cannot loop indefinitely here to avoid userspace starvation,
* but we also don't want to introduce a worst case 1/HZ latency
* to the pending events, so lets the scheduler to balance
* the softirq load for us.
*/
-static inline void wakeup_softirqd(void)
+void wakeup_softirqd(void)
{
/* Interrupts are disabled: no need to stop preemption */
struct task_struct *tsk = __get_cpu_var(ksoftirqd);
WARN_ON_ONCE(in_irq());
raw_local_irq_save(flags);
- add_preempt_count(SOFTIRQ_OFFSET);
+ /*
+ * The preempt tracer hooks into add_preempt_count and will break
+ * lockdep because it calls back into lockdep after SOFTIRQ_OFFSET
+ * is set and before current->softirq_enabled is cleared.
+ * We must manually increment preempt_count here and manually
+ * call the trace_preempt_off later.
+ */
+ preempt_count() += SOFTIRQ_OFFSET;
/*
* Were softirqs turned off above:
*/
if (softirq_count() == SOFTIRQ_OFFSET)
trace_softirqs_off(ip);
raw_local_irq_restore(flags);
+
+ if (preempt_count() == SOFTIRQ_OFFSET)
+ trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
}
#else /* !CONFIG_TRACE_IRQFLAGS */
static inline void __local_bh_disable(unsigned long ip)
account_system_vtime(current);
__local_bh_disable((unsigned long)__builtin_return_address(0));
- trace_softirq_enter();
+ lockdep_softirq_enter();
cpu = smp_processor_id();
restart:
do {
if (pending & 1) {
int prev_count = preempt_count();
+ kstat_incr_softirqs_this_cpu(h - softirq_vec);
+ trace_softirq_entry(h, softirq_vec);
h->action(h);
-
+ trace_softirq_exit(h, softirq_vec);
if (unlikely(prev_count != preempt_count())) {
- printk(KERN_ERR "huh, entered softirq %td %p"
+ printk(KERN_ERR "huh, entered softirq %td %s %p"
"with preempt_count %08x,"
" exited with %08x?\n", h - softirq_vec,
+ softirq_to_name[h - softirq_vec],
h->action, prev_count, preempt_count());
preempt_count() = prev_count;
}
- rcu_bh_qsctr_inc(cpu);
+ rcu_bh_qs(cpu);
}
h++;
pending >>= 1;
if (pending)
wakeup_softirqd();
- trace_softirq_exit();
+ lockdep_softirq_exit();
account_system_vtime(current);
_local_bh_enable();
if (!in_interrupt() && local_softirq_pending())
invoke_softirq();
+ rcu_irq_exit();
#ifdef CONFIG_NO_HZ
/* Make sure that timer wheel updates are propagated */
- rcu_irq_exit();
if (idle_cpu(smp_processor_id()) && !in_interrupt() && !need_resched())
tick_nohz_stop_sched_tick(0);
#endif
softirq_vec[nr].action = action;
}
-/* Tasklets */
+/*
+ * Tasklets
+ */
struct tasklet_head
{
struct tasklet_struct *head;
EXPORT_SYMBOL(__tasklet_hi_schedule);
+void __tasklet_hi_schedule_first(struct tasklet_struct *t)
+{
+ BUG_ON(!irqs_disabled());
+
+ t->next = __get_cpu_var(tasklet_hi_vec).head;
+ __get_cpu_var(tasklet_hi_vec).head = t;
+ __raise_softirq_irqoff(HI_SOFTIRQ);
+}
+
+EXPORT_SYMBOL(__tasklet_hi_schedule_first);
+
static void tasklet_action(struct softirq_action *a)
{
struct tasklet_struct *list;
printk("Attempt to kill tasklet from interrupt\n");
while (test_and_set_bit(TASKLET_STATE_SCHED, &t->state)) {
- do
+ do {
yield();
- while (test_bit(TASKLET_STATE_SCHED, &t->state));
+ } while (test_bit(TASKLET_STATE_SCHED, &t->state));
}
tasklet_unlock_wait(t);
clear_bit(TASKLET_STATE_SCHED, &t->state);
EXPORT_SYMBOL(tasklet_kill);
+/*
+ * tasklet_hrtimer
+ */
+
+/*
+ * The trampoline is called when the hrtimer expires. It schedules a tasklet
+ * to run __tasklet_hrtimer_trampoline() which in turn will call the intended
+ * hrtimer callback, but from softirq context.
+ */
+static enum hrtimer_restart __hrtimer_tasklet_trampoline(struct hrtimer *timer)
+{
+ struct tasklet_hrtimer *ttimer =
+ container_of(timer, struct tasklet_hrtimer, timer);
+
+ tasklet_hi_schedule(&ttimer->tasklet);
+ return HRTIMER_NORESTART;
+}
+
+/*
+ * Helper function which calls the hrtimer callback from
+ * tasklet/softirq context
+ */
+static void __tasklet_hrtimer_trampoline(unsigned long data)
+{
+ struct tasklet_hrtimer *ttimer = (void *)data;
+ enum hrtimer_restart restart;
+
+ restart = ttimer->function(&ttimer->timer);
+ if (restart != HRTIMER_NORESTART)
+ hrtimer_restart(&ttimer->timer);
+}
+
+/**
+ * tasklet_hrtimer_init - Init a tasklet/hrtimer combo for softirq callbacks
+ * @ttimer: tasklet_hrtimer which is initialized
+ * @function: hrtimer callback funtion which gets called from softirq context
+ * @which_clock: clock id (CLOCK_MONOTONIC/CLOCK_REALTIME)
+ * @mode: hrtimer mode (HRTIMER_MODE_ABS/HRTIMER_MODE_REL)
+ */
+void tasklet_hrtimer_init(struct tasklet_hrtimer *ttimer,
+ enum hrtimer_restart (*function)(struct hrtimer *),
+ clockid_t which_clock, enum hrtimer_mode mode)
+{
+ hrtimer_init(&ttimer->timer, which_clock, mode);
+ ttimer->timer.function = __hrtimer_tasklet_trampoline;
+ tasklet_init(&ttimer->tasklet, __tasklet_hrtimer_trampoline,
+ (unsigned long)ttimer);
+ ttimer->function = function;
+}
+EXPORT_SYMBOL_GPL(tasklet_hrtimer_init);
+
+/*
+ * Remote softirq bits
+ */
+
DEFINE_PER_CPU(struct list_head [NR_SOFTIRQS], softirq_work_list);
EXPORT_PER_CPU_SYMBOL(softirq_work_list);
open_softirq(HI_SOFTIRQ, tasklet_hi_action);
}
-static int ksoftirqd(void * __bind_cpu)
+static int run_ksoftirqd(void * __bind_cpu)
{
set_current_state(TASK_INTERRUPTIBLE);
preempt_enable_no_resched();
cond_resched();
preempt_disable();
- rcu_qsctr_inc((long)__bind_cpu);
+ rcu_note_context_switch((long)__bind_cpu);
}
preempt_enable();
set_current_state(TASK_INTERRUPTIBLE);
switch (action) {
case CPU_UP_PREPARE:
case CPU_UP_PREPARE_FROZEN:
- p = kthread_create(ksoftirqd, hcpu, "ksoftirqd/%d", hotcpu);
+ p = kthread_create(run_ksoftirqd, hcpu, "ksoftirqd/%d", hotcpu);
if (IS_ERR(p)) {
printk("ksoftirqd for %i failed\n", hotcpu);
return NOTIFY_BAD;
return 0;
}
-int __weak arch_init_chip_data(struct irq_desc *desc, int cpu)
+int __weak arch_init_chip_data(struct irq_desc *desc, int node)
{
return 0;
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff