mirror of
https://github.com/torvalds/linux.git
synced 2024-11-25 05:32:00 +00:00
f7b3ea8cf7
group_cpus_evenly() has become a generic function which can be used for other subsystems than the interrupt subsystem, so move it into lib/. Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jens Axboe <axboe@kernel.dk> Link: https://lore.kernel.org/r/20221227022905.352674-6-ming.lei@redhat.com
129 lines
3.4 KiB
C
129 lines
3.4 KiB
C
// 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>
|
|
#include <linux/group_cpus.h>
|
|
|
|
static void default_calc_sets(struct irq_affinity *affd, unsigned int affvecs)
|
|
{
|
|
affd->nr_sets = 1;
|
|
affd->set_size[0] = affvecs;
|
|
}
|
|
|
|
/**
|
|
* irq_create_affinity_masks - Create affinity masks for multiqueue spreading
|
|
* @nvecs: The total number of vectors
|
|
* @affd: Description of the affinity requirements
|
|
*
|
|
* Returns the irq_affinity_desc pointer or NULL if allocation failed.
|
|
*/
|
|
struct irq_affinity_desc *
|
|
irq_create_affinity_masks(unsigned int nvecs, struct irq_affinity *affd)
|
|
{
|
|
unsigned int affvecs, curvec, usedvecs, i;
|
|
struct irq_affinity_desc *masks = NULL;
|
|
|
|
/*
|
|
* Determine the number of vectors which need interrupt affinities
|
|
* assigned. If the pre/post request exhausts the available vectors
|
|
* then nothing to do here except for invoking the calc_sets()
|
|
* callback so the device driver can adjust to the situation.
|
|
*/
|
|
if (nvecs > affd->pre_vectors + affd->post_vectors)
|
|
affvecs = nvecs - affd->pre_vectors - affd->post_vectors;
|
|
else
|
|
affvecs = 0;
|
|
|
|
/*
|
|
* Simple invocations do not provide a calc_sets() callback. Install
|
|
* the generic one.
|
|
*/
|
|
if (!affd->calc_sets)
|
|
affd->calc_sets = default_calc_sets;
|
|
|
|
/* Recalculate the sets */
|
|
affd->calc_sets(affd, affvecs);
|
|
|
|
if (WARN_ON_ONCE(affd->nr_sets > IRQ_AFFINITY_MAX_SETS))
|
|
return NULL;
|
|
|
|
/* Nothing to assign? */
|
|
if (!affvecs)
|
|
return NULL;
|
|
|
|
masks = kcalloc(nvecs, sizeof(*masks), GFP_KERNEL);
|
|
if (!masks)
|
|
return NULL;
|
|
|
|
/* Fill out vectors at the beginning that don't need affinity */
|
|
for (curvec = 0; curvec < affd->pre_vectors; curvec++)
|
|
cpumask_copy(&masks[curvec].mask, irq_default_affinity);
|
|
|
|
/*
|
|
* Spread on present CPUs starting from affd->pre_vectors. If we
|
|
* have multiple sets, build each sets affinity mask separately.
|
|
*/
|
|
for (i = 0, usedvecs = 0; i < affd->nr_sets; i++) {
|
|
unsigned int this_vecs = affd->set_size[i];
|
|
int j;
|
|
struct cpumask *result = group_cpus_evenly(this_vecs);
|
|
|
|
if (!result) {
|
|
kfree(masks);
|
|
return NULL;
|
|
}
|
|
|
|
for (j = 0; j < this_vecs; j++)
|
|
cpumask_copy(&masks[curvec + j].mask, &result[j]);
|
|
kfree(result);
|
|
|
|
curvec += this_vecs;
|
|
usedvecs += this_vecs;
|
|
}
|
|
|
|
/* 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].mask, irq_default_affinity);
|
|
|
|
/* Mark the managed interrupts */
|
|
for (i = affd->pre_vectors; i < nvecs - affd->post_vectors; i++)
|
|
masks[i].is_managed = 1;
|
|
|
|
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
|
|
*/
|
|
unsigned int irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,
|
|
const struct irq_affinity *affd)
|
|
{
|
|
unsigned int resv = affd->pre_vectors + affd->post_vectors;
|
|
unsigned int set_vecs;
|
|
|
|
if (resv > minvec)
|
|
return 0;
|
|
|
|
if (affd->calc_sets) {
|
|
set_vecs = maxvec - resv;
|
|
} else {
|
|
cpus_read_lock();
|
|
set_vecs = cpumask_weight(cpu_possible_mask);
|
|
cpus_read_unlock();
|
|
}
|
|
|
|
return resv + min(set_vecs, maxvec - resv);
|
|
}
|