155 lines
3.7 KiB
C
155 lines
3.7 KiB
C
|
|
#include <linux/interrupt.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/cpu.h>
|
|
|
|
static void irq_spread_init_one(struct cpumask *irqmsk, struct cpumask *nmsk,
|
|
int cpus_per_vec)
|
|
{
|
|
const struct cpumask *siblmsk;
|
|
int cpu, sibl;
|
|
|
|
for ( ; cpus_per_vec > 0; ) {
|
|
cpu = cpumask_first(nmsk);
|
|
|
|
/* Should not happen, but I'm too lazy to think about it */
|
|
if (cpu >= nr_cpu_ids)
|
|
return;
|
|
|
|
cpumask_clear_cpu(cpu, nmsk);
|
|
cpumask_set_cpu(cpu, irqmsk);
|
|
cpus_per_vec--;
|
|
|
|
/* If the cpu has siblings, use them first */
|
|
siblmsk = topology_sibling_cpumask(cpu);
|
|
for (sibl = -1; cpus_per_vec > 0; ) {
|
|
sibl = cpumask_next(sibl, siblmsk);
|
|
if (sibl >= nr_cpu_ids)
|
|
break;
|
|
if (!cpumask_test_and_clear_cpu(sibl, nmsk))
|
|
continue;
|
|
cpumask_set_cpu(sibl, irqmsk);
|
|
cpus_per_vec--;
|
|
}
|
|
}
|
|
}
|
|
|
|
static int get_nodes_in_cpumask(const struct cpumask *mask, nodemask_t *nodemsk)
|
|
{
|
|
int n, nodes;
|
|
|
|
/* Calculate the number of nodes in the supplied affinity mask */
|
|
for (n = 0, nodes = 0; n < num_online_nodes(); n++) {
|
|
if (cpumask_intersects(mask, cpumask_of_node(n))) {
|
|
node_set(n, *nodemsk);
|
|
nodes++;
|
|
}
|
|
}
|
|
return nodes;
|
|
}
|
|
|
|
/**
|
|
* 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
|
|
*
|
|
* Returns the masks pointer or NULL if allocation failed.
|
|
*/
|
|
struct cpumask *irq_create_affinity_masks(const struct cpumask *affinity,
|
|
int nvec)
|
|
{
|
|
int n, nodes, vecs_per_node, cpus_per_vec, extra_vecs, curvec = 0;
|
|
nodemask_t nodemsk = NODE_MASK_NONE;
|
|
struct cpumask *masks;
|
|
cpumask_var_t nmsk;
|
|
|
|
if (!zalloc_cpumask_var(&nmsk, GFP_KERNEL))
|
|
return NULL;
|
|
|
|
masks = kzalloc(nvec * sizeof(*masks), GFP_KERNEL);
|
|
if (!masks)
|
|
goto out;
|
|
|
|
/* 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);
|
|
|
|
/*
|
|
* 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) {
|
|
for_each_node_mask(n, nodemsk) {
|
|
cpumask_copy(masks + curvec, cpumask_of_node(n));
|
|
if (++curvec == nvec)
|
|
break;
|
|
}
|
|
goto outonl;
|
|
}
|
|
|
|
/* Spread the vectors per node */
|
|
vecs_per_node = nvec / nodes;
|
|
/* Account for rounding errors */
|
|
extra_vecs = nvec - (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));
|
|
|
|
/* Calculate the number of cpus per vector */
|
|
ncpus = cpumask_weight(nmsk);
|
|
|
|
for (v = 0; curvec < nvec && v < vecs_to_assign; curvec++, v++) {
|
|
cpus_per_vec = ncpus / vecs_to_assign;
|
|
|
|
/* Account for extra vectors to compensate rounding errors */
|
|
if (extra_vecs) {
|
|
cpus_per_vec++;
|
|
if (!--extra_vecs)
|
|
vecs_per_node++;
|
|
}
|
|
irq_spread_init_one(masks + curvec, nmsk, cpus_per_vec);
|
|
}
|
|
|
|
if (curvec >= nvec)
|
|
break;
|
|
}
|
|
|
|
outonl:
|
|
put_online_cpus();
|
|
out:
|
|
free_cpumask_var(nmsk);
|
|
return masks;
|
|
}
|
|
|
|
/**
|
|
* 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
|
|
*/
|
|
int irq_calc_affinity_vectors(const struct cpumask *affinity, int maxvec)
|
|
{
|
|
int cpus, ret;
|
|
|
|
/* 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;
|
|
|
|
put_online_cpus();
|
|
return ret;
|
|
}
|