softirq: Consolidate common code in tasklet_[hi]_action()
tasklet_action() + tasklet_hi_action() are almost identical. Move the
common code from both function into __tasklet_action_common() and let
both functions invoke it with different arguments.
[ bigeasy: Splitted out from RT's "tasklet: Prevent tasklets from going
into infinite spin in RT" and added commit message]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Julia Cartwright <juliac@eso.teric.us>
Link: https://lkml.kernel.org/r/20180227164808.10093-3-bigeasy@linutronix.de
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 2394b00..177de36 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -490,14 +490,16 @@ void __tasklet_hi_schedule(struct tasklet_struct *t)
}
EXPORT_SYMBOL(__tasklet_hi_schedule);
-static __latent_entropy void tasklet_action(struct softirq_action *a)
+static void tasklet_action_common(struct softirq_action *a,
+ struct tasklet_head *tl_head,
+ unsigned int softirq_nr)
{
struct tasklet_struct *list;
local_irq_disable();
- list = __this_cpu_read(tasklet_vec.head);
- __this_cpu_write(tasklet_vec.head, NULL);
- __this_cpu_write(tasklet_vec.tail, this_cpu_ptr(&tasklet_vec.head));
+ list = tl_head->head;
+ tl_head->head = NULL;
+ tl_head->tail = &tl_head->head;
local_irq_enable();
while (list) {
@@ -519,47 +521,21 @@ static __latent_entropy void tasklet_action(struct softirq_action *a)
local_irq_disable();
t->next = NULL;
- *__this_cpu_read(tasklet_vec.tail) = t;
- __this_cpu_write(tasklet_vec.tail, &(t->next));
- __raise_softirq_irqoff(TASKLET_SOFTIRQ);
+ *tl_head->tail = t;
+ tl_head->tail = &t->next;
+ __raise_softirq_irqoff(softirq_nr);
local_irq_enable();
}
}
+static __latent_entropy void tasklet_action(struct softirq_action *a)
+{
+ tasklet_action_common(a, this_cpu_ptr(&tasklet_vec), TASKLET_SOFTIRQ);
+}
+
static __latent_entropy void tasklet_hi_action(struct softirq_action *a)
{
- struct tasklet_struct *list;
-
- local_irq_disable();
- list = __this_cpu_read(tasklet_hi_vec.head);
- __this_cpu_write(tasklet_hi_vec.head, NULL);
- __this_cpu_write(tasklet_hi_vec.tail, this_cpu_ptr(&tasklet_hi_vec.head));
- local_irq_enable();
-
- while (list) {
- struct tasklet_struct *t = list;
-
- list = list->next;
-
- if (tasklet_trylock(t)) {
- if (!atomic_read(&t->count)) {
- if (!test_and_clear_bit(TASKLET_STATE_SCHED,
- &t->state))
- BUG();
- t->func(t->data);
- tasklet_unlock(t);
- continue;
- }
- tasklet_unlock(t);
- }
-
- local_irq_disable();
- t->next = NULL;
- *__this_cpu_read(tasklet_hi_vec.tail) = t;
- __this_cpu_write(tasklet_hi_vec.tail, &(t->next));
- __raise_softirq_irqoff(HI_SOFTIRQ);
- local_irq_enable();
- }
+ tasklet_action_common(a, this_cpu_ptr(&tasklet_hi_vec), HI_SOFTIRQ);
}
void tasklet_init(struct tasklet_struct *t,
