Commit 82b691be authored by Ingo Molnar's avatar Ingo Molnar Committed by Thomas Gleixner

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: default avatarIngo Molnar <mingo@kernel.org>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Julia Cartwright <juliac@eso.teric.us>
Link: https://lkml.kernel.org/r/20180227164808.10093-3-bigeasy@linutronix.de
parent 6498ddad
......@@ -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_hi_action(struct softirq_action *a)
static __latent_entropy void tasklet_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);
}
tasklet_action_common(a, this_cpu_ptr(&tasklet_vec), TASKLET_SOFTIRQ);
}
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();
}
static __latent_entropy void tasklet_hi_action(struct softirq_action *a)
{
tasklet_action_common(a, this_cpu_ptr(&tasklet_hi_vec), HI_SOFTIRQ);
}
void tasklet_init(struct tasklet_struct *t,
......
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