From 82b691bedf05f258f1c86c96ee574b0d7795c0a1 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Tue, 27 Feb 2018 17:48:08 +0100 Subject: [PATCH] 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 Signed-off-by: Steven Rostedt Signed-off-by: Thomas Gleixner Signed-off-by: Sebastian Andrzej Siewior Cc: Julia Cartwright Link: https://lkml.kernel.org/r/20180227164808.10093-3-bigeasy@linutronix.de --- kernel/softirq.c | 54 ++++++++++++++---------------------------------- 1 file changed, 15 insertions(+), 39 deletions(-) diff --git a/kernel/softirq.c b/kernel/softirq.c index 2394b009994f..177de3640c78 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,