From 76cb841cb886eef6b3bee341a2266c76578724ad Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Mon, 6 May 2024 03:02:30 +0200 Subject: Adding upstream version 4.19.249. Signed-off-by: Daniel Baumann --- block/blk-mq-cpumap.c | 75 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+) create mode 100644 block/blk-mq-cpumap.c (limited to 'block/blk-mq-cpumap.c') diff --git a/block/blk-mq-cpumap.c b/block/blk-mq-cpumap.c new file mode 100644 index 000000000..3eb169f15 --- /dev/null +++ b/block/blk-mq-cpumap.c @@ -0,0 +1,75 @@ +/* + * CPU <-> hardware queue mapping helpers + * + * Copyright (C) 2013-2014 Jens Axboe + */ +#include +#include +#include +#include +#include +#include + +#include +#include "blk.h" +#include "blk-mq.h" + +static int cpu_to_queue_index(unsigned int nr_queues, const int cpu) +{ + return 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_tag_set *set) +{ + unsigned int *map = set->mq_map; + unsigned int nr_queues = set->nr_hw_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 + * performace optimizations. + */ + if (cpu < nr_queues) { + map[cpu] = cpu_to_queue_index(nr_queues, cpu); + } else { + first_sibling = get_first_sibling(cpu); + if (first_sibling == cpu) + map[cpu] = cpu_to_queue_index(nr_queues, cpu); + else + map[cpu] = map[first_sibling]; + } + } + + return 0; +} +EXPORT_SYMBOL_GPL(blk_mq_map_queues); + +/* + * 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(unsigned int *mq_map, unsigned int index) +{ + int i; + + for_each_possible_cpu(i) { + if (index == mq_map[i]) + return local_memory_node(cpu_to_node(i)); + } + + return NUMA_NO_NODE; +} -- cgit v1.2.3