mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-23 20:53:53 +08:00
556f36e90d
Spread queues among present CPUs first, then building mapping on other non-present CPUs. So we can minimize count of dead queues which are mapped by un-present CPUs only. Then bad IO performance can be avoided by unbalanced mapping between present CPUs and queues. The similar policy has been applied on Managed IRQ affinity. Cc: Yi Zhang <yi.zhang@redhat.com> Reported-by: Yi Zhang <yi.zhang@redhat.com> Reviewed-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
97 lines
2.2 KiB
C
97 lines
2.2 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 queue_index(struct blk_mq_queue_map *qmap,
|
|
unsigned int nr_queues, const int q)
|
|
{
|
|
return qmap->queue_offset + (q % 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, q = 0;
|
|
|
|
for_each_possible_cpu(cpu)
|
|
map[cpu] = -1;
|
|
|
|
/*
|
|
* Spread queues among present CPUs first for minimizing
|
|
* count of dead queues which are mapped by all un-present CPUs
|
|
*/
|
|
for_each_present_cpu(cpu) {
|
|
if (q >= nr_queues)
|
|
break;
|
|
map[cpu] = queue_index(qmap, nr_queues, q++);
|
|
}
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
if (map[cpu] != -1)
|
|
continue;
|
|
/*
|
|
* 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 (q < nr_queues) {
|
|
map[cpu] = queue_index(qmap, nr_queues, q++);
|
|
} else {
|
|
first_sibling = get_first_sibling(cpu);
|
|
if (first_sibling == cpu)
|
|
map[cpu] = queue_index(qmap, nr_queues, q++);
|
|
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;
|
|
}
|