[PATCH 3/7] genirq/affinity: Handle pre/post vectors in irq_create_affinity_masks()
From: Christoph Hellwig
Date: Tue Nov 08 2016 - 20:17:13 EST
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: Christoph Hellwig <hch@xxxxxx>
Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
---
drivers/pci/msi.c | 6 ++++--
include/linux/interrupt.h | 4 ++--
kernel/irq/affinity.c | 46 +++++++++++++++++++++++++---------------------
3 files changed, 31 insertions(+), 25 deletions(-)
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index dad2da7..f4a108b 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -553,12 +553,13 @@ static int populate_msi_sysfs(struct pci_dev *pdev)
static struct msi_desc *
msi_setup_entry(struct pci_dev *dev, int nvec, bool affinity)
{
+ static const struct irq_affinity default_affd;
struct cpumask *masks = NULL;
struct msi_desc *entry;
u16 control;
if (affinity) {
- masks = irq_create_affinity_masks(dev->irq_affinity, nvec);
+ masks = irq_create_affinity_masks(nvec, &default_affd);
if (!masks)
pr_err("Unable to allocate affinity masks, ignoring\n");
}
@@ -692,12 +693,13 @@ static int msix_setup_entries(struct pci_dev *dev, void __iomem *base,
struct msix_entry *entries, int nvec,
bool affinity)
{
+ static const struct irq_affinity default_affd;
struct cpumask *curmsk, *masks = NULL;
struct msi_desc *entry;
int ret, i;
if (affinity) {
- masks = irq_create_affinity_masks(dev->irq_affinity, nvec);
+ masks = irq_create_affinity_masks(nvec, &default_affd);
if (!masks)
pr_err("Unable to allocate affinity masks, ignoring\n");
}
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 9081f23b..53144e7 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -290,7 +290,7 @@ extern int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m);
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);
+struct cpumask *irq_create_affinity_masks(int nvec, const struct irq_affinity *affd);
int irq_calc_affinity_vectors(int maxvec, const struct irq_affinity *affd);
#else /* CONFIG_SMP */
@@ -325,7 +325,7 @@ irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
}
static inline struct cpumask *
-irq_create_affinity_masks(const struct cpumask *affinity, int nvec)
+irq_create_affinity_masks(int nvec, const struct irq_affinity *affd)
{
return NULL;
}
diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c
index 8d92597..17360bd 100644
--- a/kernel/irq/affinity.c
+++ b/kernel/irq/affinity.c
@@ -51,16 +51,16 @@ static int get_nodes_in_cpumask(const struct cpumask *mask, nodemask_t *nodemsk)
/**
* irq_create_affinity_masks - Create affinity masks for multiqueue spreading
- * @affinity: The affinity mask to spread. If NULL cpu_online_mask
- * is used
- * @nvecs: The number of vectors
+ * @nvecs: The total number of vectors
+ * @affd: Description of the affinity requirements
*
* Returns the masks pointer or NULL if allocation failed.
*/
-struct cpumask *irq_create_affinity_masks(const struct cpumask *affinity,
- int nvec)
+struct cpumask *
+irq_create_affinity_masks(int nvecs, const struct irq_affinity *affd)
{
- int n, nodes, vecs_per_node, cpus_per_vec, extra_vecs, curvec = 0;
+ int n, nodes, vecs_per_node, cpus_per_vec, extra_vecs, curvec;
+ int affv = nvecs - affd->pre_vectors - affd->post_vectors;
nodemask_t nodemsk = NODE_MASK_NONE;
struct cpumask *masks;
cpumask_var_t nmsk;
@@ -68,46 +68,46 @@ struct cpumask *irq_create_affinity_masks(const struct cpumask *affinity,
if (!zalloc_cpumask_var(&nmsk, GFP_KERNEL))
return NULL;
- masks = kzalloc(nvec * sizeof(*masks), GFP_KERNEL);
+ masks = kcalloc(nvecs, sizeof(*masks), GFP_KERNEL);
if (!masks)
goto out;
+ /* Fill out vectors at the beginning that don't need affinity */
+ for (curvec = 0; curvec < affd->pre_vectors; curvec++)
+ cpumask_copy(masks + curvec, cpu_possible_mask);
+
/* Stabilize the cpumasks */
get_online_cpus();
- /* If the supplied affinity mask is NULL, use cpu online mask */
- if (!affinity)
- affinity = cpu_online_mask;
-
- nodes = get_nodes_in_cpumask(affinity, &nodemsk);
+ nodes = get_nodes_in_cpumask(cpu_online_mask, &nodemsk);
/*
* If the number of nodes in the mask is less than or equal the
* number of vectors we just spread the vectors across the nodes.
*/
- if (nvec <= nodes) {
+ if (affv <= nodes) {
for_each_node_mask(n, nodemsk) {
cpumask_copy(masks + curvec, cpumask_of_node(n));
- if (++curvec == nvec)
+ if (++curvec == affv)
break;
}
- goto outonl;
+ goto done;
}
/* Spread the vectors per node */
- vecs_per_node = nvec / nodes;
+ vecs_per_node = affv / nodes;
/* Account for rounding errors */
- extra_vecs = nvec - (nodes * vecs_per_node);
+ extra_vecs = affv - (nodes * vecs_per_node);
for_each_node_mask(n, nodemsk) {
int ncpus, v, vecs_to_assign = vecs_per_node;
/* Get the cpus on this node which are in the mask */
- cpumask_and(nmsk, affinity, cpumask_of_node(n));
+ cpumask_and(nmsk, cpu_online_mask, cpumask_of_node(n));
/* Calculate the number of cpus per vector */
ncpus = cpumask_weight(nmsk);
- for (v = 0; curvec < nvec && v < vecs_to_assign; curvec++, v++) {
+ for (v = 0; curvec < affv && v < vecs_to_assign; curvec++, v++) {
cpus_per_vec = ncpus / vecs_to_assign;
/* Account for extra vectors to compensate rounding errors */
@@ -119,12 +119,16 @@ struct cpumask *irq_create_affinity_masks(const struct cpumask *affinity,
irq_spread_init_one(masks + curvec, nmsk, cpus_per_vec);
}
- if (curvec >= nvec)
+ if (curvec >= affv)
break;
}
-outonl:
+done:
put_online_cpus();
+
+ /* Fill out vectors at the end that don't need affinity */
+ for (; curvec < nvecs; curvec++)
+ cpumask_copy(masks + curvec, cpu_possible_mask);
out:
free_cpumask_var(nmsk);
return masks;
--
2.1.4