1 // SPDX-License-Identifier: GPL-2.0 <<
2 /* 1 /*
3 * CPU <-> hardware queue mapping helpers 2 * CPU <-> hardware queue mapping helpers
4 * 3 *
5 * Copyright (C) 2013-2014 Jens Axboe 4 * Copyright (C) 2013-2014 Jens Axboe
6 */ 5 */
7 #include <linux/kernel.h> 6 #include <linux/kernel.h>
8 #include <linux/threads.h> 7 #include <linux/threads.h>
9 #include <linux/module.h> 8 #include <linux/module.h>
10 #include <linux/mm.h> 9 #include <linux/mm.h>
11 #include <linux/smp.h> 10 #include <linux/smp.h>
12 #include <linux/cpu.h> 11 #include <linux/cpu.h>
13 #include <linux/group_cpus.h> <<
14 12
>> 13 #include <linux/blk-mq.h>
15 #include "blk.h" 14 #include "blk.h"
16 #include "blk-mq.h" 15 #include "blk-mq.h"
17 16
18 void blk_mq_map_queues(struct blk_mq_queue_map !! 17 static int cpu_to_queue_index(unsigned int nr_queues, const int cpu)
19 { 18 {
20 const struct cpumask *masks; !! 19 return cpu % nr_queues;
21 unsigned int queue, cpu; !! 20 }
22 21
23 masks = group_cpus_evenly(qmap->nr_que !! 22 static int get_first_sibling(unsigned int cpu)
24 if (!masks) { !! 23 {
25 for_each_possible_cpu(cpu) !! 24 unsigned int ret;
26 qmap->mq_map[cpu] = qm !! 25
27 return; !! 26 ret = cpumask_first(topology_sibling_cpumask(cpu));
28 } !! 27 if (ret < nr_cpu_ids)
>> 28 return ret;
>> 29
>> 30 return cpu;
>> 31 }
29 32
30 for (queue = 0; queue < qmap->nr_queue !! 33 int blk_mq_map_queues(struct blk_mq_tag_set *set)
31 for_each_cpu(cpu, &masks[queue !! 34 {
32 qmap->mq_map[cpu] = qm !! 35 unsigned int *map = set->mq_map;
>> 36 unsigned int nr_queues = set->nr_hw_queues;
>> 37 unsigned int cpu, first_sibling;
>> 38
>> 39 for_each_possible_cpu(cpu) {
>> 40 /*
>> 41 * First do sequential mapping between CPUs and queues.
>> 42 * In case we still have CPUs to map, and we have some number of
>> 43 * threads per cores then map sibling threads to the same queue for
>> 44 * performace optimizations.
>> 45 */
>> 46 if (cpu < nr_queues) {
>> 47 map[cpu] = cpu_to_queue_index(nr_queues, cpu);
>> 48 } else {
>> 49 first_sibling = get_first_sibling(cpu);
>> 50 if (first_sibling == cpu)
>> 51 map[cpu] = cpu_to_queue_index(nr_queues, cpu);
>> 52 else
>> 53 map[cpu] = map[first_sibling];
>> 54 }
33 } 55 }
34 kfree(masks); !! 56
>> 57 return 0;
35 } 58 }
36 EXPORT_SYMBOL_GPL(blk_mq_map_queues); 59 EXPORT_SYMBOL_GPL(blk_mq_map_queues);
37 60
38 /** !! 61 /*
39 * blk_mq_hw_queue_to_node - Look up the memor <<
40 * @qmap: CPU to hardware queue map. <<
41 * @index: hardware queue index. <<
42 * <<
43 * We have no quick way of doing reverse looku 62 * We have no quick way of doing reverse lookups. This is only used at
44 * queue init time, so runtime isn't important 63 * queue init time, so runtime isn't important.
45 */ 64 */
46 int blk_mq_hw_queue_to_node(struct blk_mq_queu !! 65 int blk_mq_hw_queue_to_node(unsigned int *mq_map, unsigned int index)
47 { 66 {
48 int i; 67 int i;
49 68
50 for_each_possible_cpu(i) { 69 for_each_possible_cpu(i) {
51 if (index == qmap->mq_map[i]) !! 70 if (index == mq_map[i])
52 return cpu_to_node(i); !! 71 return local_memory_node(cpu_to_node(i));
53 } 72 }
54 73
55 return NUMA_NO_NODE; 74 return NUMA_NO_NODE;
56 } 75 }
57 76
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