workqueue: Use raise_softirq() to trigger softirq in irq_work handler

bh_pool_kick_normal() and bh_pool_kick_highpri() are registered via init_irq_work() without the IRQ_WORK_HARD_IRQ flag. On PREEMPT_RT, such irq_work items are processed by the per-CPU irq_workd kthread in preemptible task context with IRQs enabled. However, raise_softirq_irqoff() requires IRQs to be disabled. Calling it from irq_workd trips the lockdep assertion in __raise_softirq_irqoff() and the non-atomic update of the softirq pending mask can lose bits raised by an interrupt on the same CPU. Replace raise_softirq_irqoff() with raise_softirq() in the irq_work handlers.

Zqiang committed 4 months ago

Commit 7e2f2a31 parent 6eca8f91 file · +2 −2Browse files

Showing the changes to kernel/workqueue.c (1 of 1 file). Show all

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kernel/workqueue.c+2−2

@@ -8065,12 +8065,12 @@ static inline void wq_watchdog_init(void) { } · 8064 unmodified lines
8065	8065
8066	8066	static void bh_pool_kick_normal(struct irq_work *irq_work)
8067	8067	{
8068		− raise_softirq_irqoff(TASKLET_SOFTIRQ);
	8068	+ raise_softirq(TASKLET_SOFTIRQ);
8069	8069	}
8070	8070
8071	8071	static void bh_pool_kick_highpri(struct irq_work *irq_work)
8072	8072	{
8073		− raise_softirq_irqoff(HI_SOFTIRQ);
	8073	+ raise_softirq(HI_SOFTIRQ);
8074	8074	}
8075	8075
8076	8076	static void __init restrict_unbound_cpumask(const char name, const struct cpumask mask)