[PATCH 2/7] genirq/affinity: Handle pre/post vectors in irq_calc_affinity_vectors()

From: Christoph Hellwig
Date: Mon Nov 07 2016 - 13:47:54 EST


From: Christogh Hellwig <hch@xxxxxx>

Only calculate the affinity for the main I/O vectors, and skip the
pre or post vectors specified by struct irq_affinity.

Also remove the irq_affinity cpumask argument that has never been used.
If we ever need it in the future we can pass it through struct
irq_affinity.

Signed-off-by: Christogh Hellwig <hch@xxxxxx>
---
drivers/pci/msi.c | 6 ++----
include/linux/interrupt.h | 4 ++--
kernel/irq/affinity.c | 24 ++++++++++--------------
3 files changed, 14 insertions(+), 20 deletions(-)

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index ad70507..c58d3c2 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -1091,8 +1091,7 @@ static int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec,

for (;;) {
if (affinity) {
- nvec = irq_calc_affinity_vectors(dev->irq_affinity,
- nvec);
+ nvec = irq_calc_affinity_vectors(nvec, NULL);
if (nvec < minvec)
return -ENOSPC;
}
@@ -1140,8 +1139,7 @@ static int __pci_enable_msix_range(struct pci_dev *dev,

for (;;) {
if (affinity) {
- nvec = irq_calc_affinity_vectors(dev->irq_affinity,
- nvec);
+ nvec = irq_calc_affinity_vectors(nvec, NULL);
if (nvec < minvec)
return -ENOSPC;
}
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 7284bcd..092adfb 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -291,7 +291,7 @@ extern int
irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify);

struct cpumask *irq_create_affinity_masks(const struct cpumask *affinity, int nvec);
-int irq_calc_affinity_vectors(const struct cpumask *affinity, int maxvec);
+int irq_calc_affinity_vectors(int maxvec, const struct irq_affinity *affd);

#else /* CONFIG_SMP */

@@ -331,7 +331,7 @@ irq_create_affinity_masks(const struct cpumask *affinity, int nvec)
}

static inline int
-irq_calc_affinity_vectors(const struct cpumask *affinity, int maxvec)
+irq_calc_affinity_vectors(int maxvec, const struct irq_affinity *affd)
{
return maxvec;
}
diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c
index 17f51d63..8d92597 100644
--- a/kernel/irq/affinity.c
+++ b/kernel/irq/affinity.c
@@ -131,24 +131,20 @@ struct cpumask *irq_create_affinity_masks(const struct cpumask *affinity,
}

/**
- * irq_calc_affinity_vectors - Calculate to optimal number of vectors for a given affinity mask
- * @affinity: The affinity mask to spread. If NULL cpu_online_mask
- * is used
- * @maxvec: The maximum number of vectors available
+ * irq_calc_affinity_vectors - Calculate the optimal number of vectors
+ * @maxvec: The maximum number of vectors available
+ * @affd: Description of the affinity requirements
*/
-int irq_calc_affinity_vectors(const struct cpumask *affinity, int maxvec)
+int irq_calc_affinity_vectors(int maxvec, const struct irq_affinity *affd)
{
- int cpus, ret;
+ int resv = affd->pre_vectors + affd->post_vectors;
+ int vecs = maxvec - resv;
+ int cpus;

/* Stabilize the cpumasks */
get_online_cpus();
- /* If the supplied affinity mask is NULL, use cpu online mask */
- if (!affinity)
- affinity = cpu_online_mask;
-
- cpus = cpumask_weight(affinity);
- ret = (cpus < maxvec) ? cpus : maxvec;
-
+ cpus = cpumask_weight(cpu_online_mask);
put_online_cpus();
- return ret;
+
+ return min(cpus, vecs) + resv;
}
--
2.1.4