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authorThomas Gleixner <tglx@linutronix.de>2016-02-03 19:52:23 +0100
committerThomas Gleixner <tglx@linutronix.de>2016-02-08 15:03:42 +0100
commitfbf198030e0b027538c290300cfaf9e2efdce122 (patch)
tree54c1ab89d46ccd5a0da1e79b728e09085d5af415 /kernel/irq
parentc7c42ec2baa1de7ab3965e4f1bf5073bee6065e4 (diff)
downloadlinux-sh-fbf198030e0b027538c290300cfaf9e2efdce122.tar.gz
genirq: Add default affinity mask command line option
If we isolate CPUs, then we don't want random device interrupts on them. Even w/o the user space irq balancer enabled we can end up with irqs on non boot cpus and chasing newly requested interrupts is a tedious task. Allow to restrict the default irq affinity mask. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Rik van Riel <riel@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Christoph Lameter <cl@linux.com> Cc: Sebastian Siewior <bigeasy@linutronix.de> Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1602031948190.25254@nanos Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/irq')
-rw-r--r--kernel/irq/irqdesc.c21
1 files changed, 19 insertions, 2 deletions
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index 0409da0bcc33..0ccd028817d7 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -24,10 +24,27 @@
static struct lock_class_key irq_desc_lock_class;
#if defined(CONFIG_SMP)
+static int __init irq_affinity_setup(char *str)
+{
+ zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
+ cpulist_parse(str, irq_default_affinity);
+ /*
+ * Set at least the boot cpu. We don't want to end up with
+ * bugreports caused by random comandline masks
+ */
+ cpumask_set_cpu(smp_processor_id(), irq_default_affinity);
+ return 1;
+}
+__setup("irqaffinity=", irq_affinity_setup);
+
static void __init init_irq_default_affinity(void)
{
- alloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
- cpumask_setall(irq_default_affinity);
+#ifdef CONFIG_CPUMASK_OFFSTACK
+ if (!irq_default_affinity)
+ zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
+#endif
+ if (cpumask_empty(irq_default_affinity))
+ cpumask_setall(irq_default_affinity);
}
#else
static void __init init_irq_default_affinity(void)