Commit-ID: 8f31a9845db348f5781df47ce04c79e4cfe90016 Gitweb: http://git.kernel.org/tip/8f31a9845db348f5781df47ce04c79e4cfe90016 Author: Thomas Gleixner <t...@linutronix.de> AuthorDate: Tue, 20 Jun 2017 01:37:53 +0200 Committer: Thomas Gleixner <t...@linutronix.de> CommitDate: Thu, 22 Jun 2017 18:21:25 +0200
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 <t...@linutronix.de> Cc: Jens Axboe <ax...@kernel.dk> Cc: Marc Zyngier <marc.zyng...@arm.com> Cc: Michael Ellerman <m...@ellerman.id.au> Cc: Keith Busch <keith.bu...@intel.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Christoph Hellwig <h...@lst.de> Link: http://lkml.kernel.org/r/20170619235447.431321...@linutronix.de --- kernel/irq/cpuhotplug.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/kernel/irq/cpuhotplug.c b/kernel/irq/cpuhotplug.c index b7964e7..aee8f7e 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)) return; - 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); }
