path: root/kernel/irq/cpuhotplug.c
diff options
authorThomas Gleixner <tglx@linutronix.de>2017-06-20 01:37:53 +0200
committerThomas Gleixner <tglx@linutronix.de>2017-06-22 18:21:25 +0200
commit8f31a9845db348f5781df47ce04c79e4cfe90016 (patch)
tree45f6d871655ef2859e0f558058c1b897ce6aec7f /kernel/irq/cpuhotplug.c
parentd52dd44175bd27ad9d8e34a994fb80877c1f6d61 (diff)
genirq/cpuhotplug: Avoid irq affinity setting for single targets
Avoid trying to add a newly online CPU to the effective affinity mask of an started up interrupt. That interrupt will either stay on the already online CPU or move around for no value. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Keith Busch <keith.busch@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Christoph Hellwig <hch@lst.de> Link: http://lkml.kernel.org/r/20170619235447.431321047@linutronix.de
Diffstat (limited to 'kernel/irq/cpuhotplug.c')
1 files changed, 10 insertions, 2 deletions
diff --git a/kernel/irq/cpuhotplug.c b/kernel/irq/cpuhotplug.c
index b7964e72ded7..aee8f7ec40af 100644
--- a/kernel/irq/cpuhotplug.c
+++ b/kernel/irq/cpuhotplug.c
@@ -148,9 +148,17 @@ static void irq_restore_affinity_of_irq(struct irq_desc *desc, unsigned int cpu)
!irq_data_get_irq_chip(data) || !cpumask_test_cpu(cpu, affinity))
- if (irqd_is_managed_and_shutdown(data))
+ if (irqd_is_managed_and_shutdown(data)) {
irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
- else
+ return;
+ }
+ /*
+ * If the interrupt can only be directed to a single target
+ * CPU then it is already assigned to a CPU in the affinity
+ * mask. No point in trying to move it around.
+ */
+ if (!irqd_is_single_target(data))
irq_set_affinity_locked(data, affinity, false);