genirq/affinity: Provide smarter irq spreading infrastructure

The current irq spreading infrastructure is just looking at a cpumask and
tries to spread the interrupts over the mask. Thats suboptimal as it does
not take numa nodes into account.

Change the logic so the interrupts are spread across numa nodes and inside
the nodes. If there are more cpus than vectors per node, then we set the
affinity to several cpus. If HT siblings are available we take that into
account and try to set all siblings to a single vector.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: axboe@fb.com
Cc: keith.busch@intel.com
Cc: agordeev@redhat.com
Cc: linux-block@vger.kernel.org
Link: http://lkml.kernel.org/r/1473862739-15032-3-git-send-email-hch@lst.de

1 files changed, 15 insertions, 0 deletions

diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index b6683f0ffc9f..4e59d122cad9 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -279,6 +279,8 @@ extern int
 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify);
 
 struct cpumask *irq_create_affinity_mask(unsigned int *nr_vecs);
+struct cpumask *irq_create_affinity_masks(const struct cpumask *affinity, int nvec);
+int irq_calc_affinity_vectors(const struct cpumask *affinity, int maxvec);
 
 #else /* CONFIG_SMP */
 
@@ -316,6 +318,19 @@ static inline struct cpumask *irq_create_affinity_mask(unsigned int *nr_vecs)
 	*nr_vecs = 1;
 	return NULL;
 }
+
+static inline struct cpumask *
+irq_create_affinity_masks(const struct cpumask *affinity, int nvec)
+{
+	return NULL;
+}
+
+static inline int
+irq_calc_affinity_vectors(const struct cpumask *affinity, int maxvec)
+{
+	return maxvec;
+}
+
 #endif /* CONFIG_SMP */
 
 /*