From cbf8699996a6e7f2f674b3a2a4cef9f666ff613e Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 16 Feb 2018 15:21:20 +0100 Subject: genirq: Let irq thread follow the effective hard irq affinity In case of threaded interrupts the thread follows the affinity setting of the hard interrupt. The related function uses the affinity mask which was set by either from user space or via one of the kernel mechanisms. This mask can be wider than the resulting effective affinity of the hard interrupt. As a consequence the thread might become affine to a completely different CPU. Use the effective interrupt affinity if the architecture supports it, so the hard interrupt and the thread stay on the same CPU. Reported-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Tested-by: Sebastian Andrzej Siewior --- kernel/irq/manage.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'kernel/irq') diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 0f922729bab9..d2b3c59f1200 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -855,10 +855,14 @@ irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) * This code is triggered unconditionally. Check the affinity * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out. */ - if (cpumask_available(desc->irq_common_data.affinity)) - cpumask_copy(mask, desc->irq_common_data.affinity); - else + if (cpumask_available(desc->irq_common_data.affinity)) { + const struct cpumask *m; + + m = irq_data_get_effective_affinity_mask(&desc->irq_data); + cpumask_copy(mask, m); + } else { valid = false; + } raw_spin_unlock_irq(&desc->lock); if (valid) -- cgit v1.2.3-55-g7522