mirror_ubuntu-kernels/block/blk-mq-cpumap.c

57 lines
1.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* CPU <-> hardware queue mapping helpers
*
* Copyright (C) 2013-2014 Jens Axboe
*/
#include <linux/kernel.h>
#include <linux/threads.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/cpu.h>
#include <linux/group_cpus.h>
#include "blk.h"
#include "blk-mq.h"
void blk_mq_map_queues(struct blk_mq_queue_map *qmap)
{
const struct cpumask *masks;
unsigned int queue, cpu;
masks = group_cpus_evenly(qmap->nr_queues);
if (!masks) {
for_each_possible_cpu(cpu)
qmap->mq_map[cpu] = qmap->queue_offset;
return;
}
for (queue = 0; queue < qmap->nr_queues; queue++) {
for_each_cpu(cpu, &masks[queue])
qmap->mq_map[cpu] = qmap->queue_offset + queue;
}
kfree(masks);
}
EXPORT_SYMBOL_GPL(blk_mq_map_queues);
/**
* blk_mq_hw_queue_to_node - Look up the memory node for a hardware queue index
* @qmap: CPU to hardware queue map.
* @index: hardware queue index.
*
* We have no quick way of doing reverse lookups. This is only used at
* queue init time, so runtime isn't important.
*/
int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int index)
{
int i;
for_each_possible_cpu(i) {
if (index == qmap->mq_map[i])
return cpu_to_node(i);
}
return NUMA_NO_NODE;
}