From 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 27 Apr 2024 12:05:51 +0200 Subject: Adding upstream version 5.10.209. Signed-off-by: Daniel Baumann --- block/blk-mq-cpumap.c | 96 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 96 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..3db84d319 --- /dev/null +++ b/block/blk-mq-cpumap.c @@ -0,0 +1,96 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * 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 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 cpu_to_node(i); + } + + return NUMA_NO_NODE; +} -- cgit v1.2.3