From 3ca57222c36ba31b80aa25de313f3c8ab26a8102 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 20 Jun 2017 01:37:54 +0200 Subject: [PATCH] x86/apic: Mark single target interrupts If the interrupt destination mode of the APIC is physical then the effective affinity is restricted to a single CPU. Mark the interrupt accordingly in the domain allocation code, so the core code can avoid pointless affinity setting attempts. Signed-off-by: Thomas Gleixner Cc: Jens Axboe Cc: Marc Zyngier Cc: Michael Ellerman Cc: Keith Busch Cc: Peter Zijlstra Cc: Christoph Hellwig Link: http://lkml.kernel.org/r/20170619235447.508846202@linutronix.de --- arch/x86/kernel/apic/vector.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c index b270a76ee640..2567dc012200 100644 --- a/arch/x86/kernel/apic/vector.c +++ b/arch/x86/kernel/apic/vector.c @@ -371,6 +371,13 @@ static int x86_vector_alloc_irqs(struct irq_domain *domain, unsigned int virq, irq_data); if (err) goto error; + /* + * If the apic destination mode is physical, then the + * effective affinity is restricted to a single target + * CPU. Mark the interrupt accordingly. + */ + if (!apic->irq_dest_mode) + irqd_set_single_target(irq_data); } return 0; -- 2.20.1