softirq: Consolidate common code in __tasklet_[hi]_schedule() (6498ddad) · Commits · 戴 / test

__tasklet_schedule() and __tasklet_hi_schedule() are almost identical. Move the common code from both function into __tasklet_schedule_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. Use this_cpu_ptr(headp) in __tasklet_schedule_common() as suggested by Julia Cartwright ] 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/20180227164808.10093-2-bigeasy@linutronix.de

kernel/softirq.c

+16 −12

Original line number	Diff line number	Diff line
		@@ -460,29 +460,33 @@ struct tasklet_head {
		static DEFINE_PER_CPU(struct tasklet_head, tasklet_vec);
		static DEFINE_PER_CPU(struct tasklet_head, tasklet_hi_vec);

		void __tasklet_schedule(struct tasklet_struct *t)
		static void __tasklet_schedule_common(struct tasklet_struct *t,
		struct tasklet_head __percpu *headp,
		unsigned int softirq_nr)
		{
		struct tasklet_head *head;
		unsigned long flags;

		local_irq_save(flags);
		head = this_cpu_ptr(headp);
		t->next = NULL;
		*__this_cpu_read(tasklet_vec.tail) = t;
		__this_cpu_write(tasklet_vec.tail, &(t->next));
		raise_softirq_irqoff(TASKLET_SOFTIRQ);
		*head->tail = t;
		head->tail = &(t->next);
		raise_softirq_irqoff(softirq_nr);
		local_irq_restore(flags);
		}

		void __tasklet_schedule(struct tasklet_struct *t)
		{
		__tasklet_schedule_common(t, &tasklet_vec,
		TASKLET_SOFTIRQ);
		}
		EXPORT_SYMBOL(__tasklet_schedule);

		void __tasklet_hi_schedule(struct tasklet_struct *t)
		{
		unsigned long flags;

		local_irq_save(flags);
		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_restore(flags);
		__tasklet_schedule_common(t, &tasklet_hi_vec,
		HI_SOFTIRQ);
		}
		EXPORT_SYMBOL(__tasklet_hi_schedule);

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