[PATCH V3 3/4] genirq/affinity: support to do irq vectors spread starting from any vector

From: Ming Lei
Date: Thu Mar 08 2018 - 05:54:52 EST


Now two parameters(start_vec, affv) are introduced to irq_build_affinity_masks(),
then this helper can build the affinity of each irq vector starting from
the irq vector of 'start_vec', and handle at most 'affv' vectors.

This way is required to do 2-stages irq vectors spread among all
possible CPUs.

Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
kernel/irq/affinity.c | 23 +++++++++++++++--------
1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c
index e119e86bed48..616f040c5d02 100644
--- a/kernel/irq/affinity.c
+++ b/kernel/irq/affinity.c
@@ -94,17 +94,17 @@ static int get_nodes_in_cpumask(cpumask_var_t *node_to_cpumask,
return nodes;
}

-static int irq_build_affinity_masks(int nvecs, const struct irq_affinity *affd,
+static int irq_build_affinity_masks(const struct irq_affinity *affd,
+ int start_vec, int affv,
cpumask_var_t *node_to_cpumask,
const struct cpumask *cpu_mask,
struct cpumask *nmsk,
struct cpumask *masks)
{
- int affv = nvecs - affd->pre_vectors - affd->post_vectors;
int last_affv = affv + affd->pre_vectors;
- int curvec = affd->pre_vectors;
+ int curvec = start_vec;
nodemask_t nodemsk = NODE_MASK_NONE;
- int n, nodes, cpus_per_vec, extra_vecs;
+ int n, nodes, cpus_per_vec, extra_vecs, done = 0;

nodes = get_nodes_in_cpumask(node_to_cpumask, cpu_mask, &nodemsk);

@@ -116,8 +116,10 @@ static int irq_build_affinity_masks(int nvecs, const struct irq_affinity *affd,
for_each_node_mask(n, nodemsk) {
cpumask_copy(masks + curvec,
node_to_cpumask[n]);
- if (++curvec == last_affv)
+ if (++done == affv)
break;
+ if (++curvec == last_affv)
+ curvec = affd->pre_vectors;
}
goto out;
}
@@ -150,13 +152,16 @@ static int irq_build_affinity_masks(int nvecs, const struct irq_affinity *affd,
irq_spread_init_one(masks + curvec, nmsk, cpus_per_vec);
}

- if (curvec >= last_affv)
+ done += v;
+ if (done >= affv)
break;
+ if (curvec >= last_affv)
+ curvec = affd->pre_vectors;
--nodes;
}

out:
- return curvec - affd->pre_vectors;
+ return done;
}

/**
@@ -169,6 +174,7 @@ static int irq_build_affinity_masks(int nvecs, const struct irq_affinity *affd,
struct cpumask *
irq_create_affinity_masks(int nvecs, const struct irq_affinity *affd)
{
+ int affv = nvecs - affd->pre_vectors - affd->post_vectors;
int curvec;
struct cpumask *masks;
cpumask_var_t nmsk, *node_to_cpumask;
@@ -198,7 +204,8 @@ irq_create_affinity_masks(int nvecs, const struct irq_affinity *affd)
/* Stabilize the cpumasks */
get_online_cpus();
build_node_to_cpumask(node_to_cpumask);
- curvec += irq_build_affinity_masks(nvecs, affd, node_to_cpumask,
+ curvec += irq_build_affinity_masks(affd, curvec, affv,
+ node_to_cpumask,
cpu_possible_mask, nmsk, masks);
put_online_cpus();

--
2.9.5