mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-21 20:21:06 +07:00
cd669f88b1
Document the meaning of the blk_mq_hw_queue_to_node() arguments. Reviewed-by: Chaitanya Kulkarni <chiatanya.kulkarni@wdc.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
82 lines
1.9 KiB
C
82 lines
1.9 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/blk-mq.h>
|
|
#include "blk.h"
|
|
#include "blk-mq.h"
|
|
|
|
static int cpu_to_queue_index(struct blk_mq_queue_map *qmap,
|
|
unsigned int nr_queues, const int cpu)
|
|
{
|
|
return qmap->queue_offset + (cpu % nr_queues);
|
|
}
|
|
|
|
static int get_first_sibling(unsigned int cpu)
|
|
{
|
|
unsigned int ret;
|
|
|
|
ret = cpumask_first(topology_sibling_cpumask(cpu));
|
|
if (ret < nr_cpu_ids)
|
|
return ret;
|
|
|
|
return cpu;
|
|
}
|
|
|
|
int blk_mq_map_queues(struct blk_mq_queue_map *qmap)
|
|
{
|
|
unsigned int *map = qmap->mq_map;
|
|
unsigned int nr_queues = qmap->nr_queues;
|
|
unsigned int cpu, first_sibling;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
/*
|
|
* First do sequential mapping between CPUs and queues.
|
|
* In case we still have CPUs to map, and we have some number of
|
|
* threads per cores then map sibling threads to the same queue
|
|
* for performance optimizations.
|
|
*/
|
|
if (cpu < nr_queues) {
|
|
map[cpu] = cpu_to_queue_index(qmap, nr_queues, cpu);
|
|
} else {
|
|
first_sibling = get_first_sibling(cpu);
|
|
if (first_sibling == cpu)
|
|
map[cpu] = cpu_to_queue_index(qmap, nr_queues, cpu);
|
|
else
|
|
map[cpu] = map[first_sibling];
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
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 local_memory_node(cpu_to_node(i));
|
|
}
|
|
|
|
return NUMA_NO_NODE;
|
|
}
|