[PATCH V3 2/4] genirq/affinity: move actual irq vector spread into one helper

From: Ming Lei
Date: Thu Mar 08 2018 - 05:54:43 EST


No functional change, just prepare for converting to 2-stage
irq vector spread.

Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
kernel/irq/affinity.c | 97 +++++++++++++++++++++++++++++----------------------
1 file changed, 55 insertions(+), 42 deletions(-)

diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c
index 4b1c4763212d..e119e86bed48 100644
--- a/kernel/irq/affinity.c
+++ b/kernel/irq/affinity.c
@@ -94,50 +94,19 @@ static int get_nodes_in_cpumask(cpumask_var_t *node_to_cpumask,
return nodes;
}

-/**
- * irq_create_affinity_masks - Create affinity masks for multiqueue spreading
- * @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(int nvecs, const struct irq_affinity *affd)
+static int irq_build_affinity_masks(int nvecs, const struct irq_affinity *affd,
+ cpumask_var_t *node_to_cpumask,
+ const struct cpumask *cpu_mask,
+ struct cpumask *nmsk,
+ struct cpumask *masks)
{
- int n, nodes, cpus_per_vec, extra_vecs, curvec;
int affv = nvecs - affd->pre_vectors - affd->post_vectors;
int last_affv = affv + affd->pre_vectors;
+ int curvec = affd->pre_vectors;
nodemask_t nodemsk = NODE_MASK_NONE;
- struct cpumask *masks;
- cpumask_var_t nmsk, *node_to_cpumask;
-
- /*
- * If there aren't any vectors left after applying the pre/post
- * vectors don't bother with assigning affinity.
- */
- if (!affv)
- return NULL;
-
- if (!zalloc_cpumask_var(&nmsk, GFP_KERNEL))
- return NULL;
-
- masks = kcalloc(nvecs, sizeof(*masks), GFP_KERNEL);
- if (!masks)
- goto out;
+ int n, nodes, cpus_per_vec, extra_vecs;

- node_to_cpumask = alloc_node_to_cpumask();
- if (!node_to_cpumask)
- 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, irq_default_affinity);
-
- /* Stabilize the cpumasks */
- get_online_cpus();
- build_node_to_cpumask(node_to_cpumask);
- nodes = get_nodes_in_cpumask(node_to_cpumask, cpu_possible_mask,
- &nodemsk);
+ nodes = get_nodes_in_cpumask(node_to_cpumask, cpu_mask, &nodemsk);

/*
* If the number of nodes in the mask is greater than or equal the
@@ -150,7 +119,7 @@ irq_create_affinity_masks(int nvecs, const struct irq_affinity *affd)
if (++curvec == last_affv)
break;
}
- goto done;
+ goto out;
}

for_each_node_mask(n, nodemsk) {
@@ -160,7 +129,7 @@ irq_create_affinity_masks(int nvecs, const struct irq_affinity *affd)
vecs_per_node = (affv - (curvec - affd->pre_vectors)) / nodes;

/* Get the cpus on this node which are in the mask */
- cpumask_and(nmsk, cpu_possible_mask, node_to_cpumask[n]);
+ cpumask_and(nmsk, cpu_mask, node_to_cpumask[n]);

/* Calculate the number of cpus per vector */
ncpus = cpumask_weight(nmsk);
@@ -186,7 +155,51 @@ irq_create_affinity_masks(int nvecs, const struct irq_affinity *affd)
--nodes;
}

-done:
+out:
+ return curvec - affd->pre_vectors;
+}
+
+/**
+ * irq_create_affinity_masks - Create affinity masks for multiqueue spreading
+ * @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(int nvecs, const struct irq_affinity *affd)
+{
+ int curvec;
+ struct cpumask *masks;
+ cpumask_var_t nmsk, *node_to_cpumask;
+
+ /*
+ * If there aren't any vectors left after applying the pre/post
+ * vectors don't bother with assigning affinity.
+ */
+ if (nvecs == affd->pre_vectors + affd->post_vectors)
+ return NULL;
+
+ if (!zalloc_cpumask_var(&nmsk, GFP_KERNEL))
+ return NULL;
+
+ masks = kcalloc(nvecs, sizeof(*masks), GFP_KERNEL);
+ if (!masks)
+ goto out;
+
+ node_to_cpumask = alloc_node_to_cpumask();
+ if (!node_to_cpumask)
+ 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, irq_default_affinity);
+
+ /* Stabilize the cpumasks */
+ get_online_cpus();
+ build_node_to_cpumask(node_to_cpumask);
+ curvec += irq_build_affinity_masks(nvecs, affd, node_to_cpumask,
+ cpu_possible_mask, nmsk, masks);
put_online_cpus();

/* Fill out vectors at the end that don't need affinity */
--
2.9.5