270 lines
6.7 KiB
C
Executable file
270 lines
6.7 KiB
C
Executable file
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Copyright (C) 2016 Thomas Gleixner.
|
|
* Copyright (C) 2016-2017 Christoph Hellwig.
|
|
*/
|
|
#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 cpumask_var_t *alloc_node_to_cpumask(void)
|
|
{
|
|
cpumask_var_t *masks;
|
|
int node;
|
|
|
|
masks = kcalloc(nr_node_ids, sizeof(cpumask_var_t), GFP_KERNEL);
|
|
if (!masks)
|
|
return NULL;
|
|
|
|
for (node = 0; node < nr_node_ids; node++) {
|
|
if (!zalloc_cpumask_var(&masks[node], GFP_KERNEL))
|
|
goto out_unwind;
|
|
}
|
|
|
|
return masks;
|
|
|
|
out_unwind:
|
|
while (--node >= 0)
|
|
free_cpumask_var(masks[node]);
|
|
kfree(masks);
|
|
return NULL;
|
|
}
|
|
|
|
static void free_node_to_cpumask(cpumask_var_t *masks)
|
|
{
|
|
int node;
|
|
|
|
for (node = 0; node < nr_node_ids; node++)
|
|
free_cpumask_var(masks[node]);
|
|
kfree(masks);
|
|
}
|
|
|
|
static void build_node_to_cpumask(cpumask_var_t *masks)
|
|
{
|
|
int cpu;
|
|
|
|
for_each_possible_cpu(cpu)
|
|
cpumask_set_cpu(cpu, masks[cpu_to_node(cpu)]);
|
|
}
|
|
|
|
static int get_nodes_in_cpumask(cpumask_var_t *node_to_cpumask,
|
|
const struct cpumask *mask, nodemask_t *nodemsk)
|
|
{
|
|
int n, nodes = 0;
|
|
|
|
/* Calculate the number of nodes in the supplied affinity mask */
|
|
for_each_node(n) {
|
|
if (cpumask_intersects(mask, node_to_cpumask[n])) {
|
|
node_set(n, *nodemsk);
|
|
nodes++;
|
|
}
|
|
}
|
|
return nodes;
|
|
}
|
|
|
|
static int irq_build_affinity_masks(const struct irq_affinity *affd,
|
|
int startvec, int numvecs,
|
|
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, done = 0;
|
|
int last_affv = affd->pre_vectors + numvecs;
|
|
int curvec = startvec;
|
|
nodemask_t nodemsk = NODE_MASK_NONE;
|
|
|
|
if (!cpumask_weight(cpu_mask))
|
|
return 0;
|
|
|
|
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
|
|
* number of vectors we just spread the vectors across the nodes.
|
|
*/
|
|
if (numvecs <= nodes) {
|
|
for_each_node_mask(n, nodemsk) {
|
|
cpumask_or(masks + curvec, masks + curvec, node_to_cpumask[n]);
|
|
if (++curvec == last_affv)
|
|
curvec = affd->pre_vectors;
|
|
}
|
|
done = numvecs;
|
|
goto out;
|
|
}
|
|
|
|
for_each_node_mask(n, nodemsk) {
|
|
int ncpus, v, vecs_to_assign, vecs_per_node;
|
|
|
|
/* Spread the vectors per node */
|
|
vecs_per_node = (numvecs - (curvec - affd->pre_vectors)) / nodes;
|
|
|
|
/* Get the cpus on this node which are in the mask */
|
|
cpumask_and(nmsk, cpu_mask, node_to_cpumask[n]);
|
|
|
|
/* Calculate the number of cpus per vector */
|
|
ncpus = cpumask_weight(nmsk);
|
|
vecs_to_assign = min(vecs_per_node, ncpus);
|
|
|
|
/* Account for rounding errors */
|
|
extra_vecs = ncpus - vecs_to_assign * (ncpus / vecs_to_assign);
|
|
|
|
for (v = 0; curvec < last_affv && 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++;
|
|
--extra_vecs;
|
|
}
|
|
irq_spread_init_one(masks + curvec, nmsk, cpus_per_vec);
|
|
}
|
|
|
|
done += v;
|
|
if (done >= numvecs)
|
|
break;
|
|
if (curvec >= last_affv)
|
|
curvec = affd->pre_vectors;
|
|
--nodes;
|
|
}
|
|
|
|
out:
|
|
return done;
|
|
}
|
|
|
|
/**
|
|
* 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 affvecs = nvecs - affd->pre_vectors - affd->post_vectors;
|
|
int curvec, usedvecs;
|
|
cpumask_var_t nmsk, npresmsk, *node_to_cpumask;
|
|
struct cpumask *masks = NULL;
|
|
|
|
/*
|
|
* 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;
|
|
|
|
if (!zalloc_cpumask_var(&npresmsk, GFP_KERNEL))
|
|
goto outcpumsk;
|
|
|
|
node_to_cpumask = alloc_node_to_cpumask();
|
|
if (!node_to_cpumask)
|
|
goto outnpresmsk;
|
|
|
|
masks = kcalloc(nvecs, sizeof(*masks), GFP_KERNEL);
|
|
if (!masks)
|
|
goto outnodemsk;
|
|
|
|
/* 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);
|
|
|
|
/* Spread on present CPUs starting from affd->pre_vectors */
|
|
usedvecs = irq_build_affinity_masks(affd, curvec, affvecs,
|
|
node_to_cpumask, cpu_present_mask,
|
|
nmsk, masks);
|
|
|
|
/*
|
|
* Spread on non present CPUs starting from the next vector to be
|
|
* handled. If the spreading of present CPUs already exhausted the
|
|
* vector space, assign the non present CPUs to the already spread
|
|
* out vectors.
|
|
*/
|
|
if (usedvecs >= affvecs)
|
|
curvec = affd->pre_vectors;
|
|
else
|
|
curvec = affd->pre_vectors + usedvecs;
|
|
cpumask_andnot(npresmsk, cpu_possible_mask, cpu_present_mask);
|
|
usedvecs += irq_build_affinity_masks(affd, curvec, affvecs,
|
|
node_to_cpumask, npresmsk,
|
|
nmsk, masks);
|
|
put_online_cpus();
|
|
|
|
/* Fill out vectors at the end that don't need affinity */
|
|
if (usedvecs >= affvecs)
|
|
curvec = affd->pre_vectors + affvecs;
|
|
else
|
|
curvec = affd->pre_vectors + usedvecs;
|
|
for (; curvec < nvecs; curvec++)
|
|
cpumask_copy(masks + curvec, irq_default_affinity);
|
|
|
|
outnodemsk:
|
|
free_node_to_cpumask(node_to_cpumask);
|
|
outnpresmsk:
|
|
free_cpumask_var(npresmsk);
|
|
outcpumsk:
|
|
free_cpumask_var(nmsk);
|
|
return masks;
|
|
}
|
|
|
|
/**
|
|
* irq_calc_affinity_vectors - Calculate the optimal number of vectors
|
|
* @minvec: The minimum number of vectors available
|
|
* @maxvec: The maximum number of vectors available
|
|
* @affd: Description of the affinity requirements
|
|
*/
|
|
int irq_calc_affinity_vectors(int minvec, int maxvec, const struct irq_affinity *affd)
|
|
{
|
|
int resv = affd->pre_vectors + affd->post_vectors;
|
|
int vecs = maxvec - resv;
|
|
int ret;
|
|
|
|
if (resv > minvec)
|
|
return 0;
|
|
|
|
get_online_cpus();
|
|
ret = min_t(int, cpumask_weight(cpu_possible_mask), vecs) + resv;
|
|
put_online_cpus();
|
|
return ret;
|
|
}
|