[v2] block: fix rdma queue mapping

Message ID	20180820205420.25908-1-sagi@grimberg.me (mailing list archive)
State	Not Applicable
Headers	show Return-Path: <linux-rdma-owner@kernel.org> From: Sagi Grimberg <sagi@grimberg.me> To: linux-block@vger.kernel.org, linux-rdma@vger.kernel.org, linux-nvme@lists.infradead.org Cc: Christoph Hellwig <hch@lst.de>, Steve Wise <swise@opengridcomputing.com>, Max Gurtovoy <maxg@mellanox.com> Subject: [PATCH v2] block: fix rdma queue mapping Date: Mon, 20 Aug 2018 13:54:20 -0700 Message-Id: <20180820205420.25908-1-sagi@grimberg.me> Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk
Series	[v2] block: fix rdma queue mapping \| expand [v2] block: fix rdma queue mapping

diff --git a/block/blk-mq-cpumap.c b/block/blk-mq-cpumap.c index 3eb169f15842..34811db8cba9 100644 --- a/block/blk-mq-cpumap.c +++ b/block/blk-mq-cpumap.c @@ -30,30 +30,35 @@ static int get_first_sibling(unsigned int cpu) return cpu; } -int blk_mq_map_queues(struct blk_mq_tag_set *set) +void blk_mq_map_queue_cpu(struct blk_mq_tag_set *set, unsigned int cpu) { unsigned int *map = set->mq_map; unsigned int nr_queues = set->nr_hw_queues; - unsigned int cpu, first_sibling; + unsigned int 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) { + /* + * 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 { - 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]; - } + else + map[cpu] = map[first_sibling]; } +} + +int blk_mq_map_queues(struct blk_mq_tag_set *set) +{ + unsigned int cpu; + for_each_possible_cpu(cpu) + blk_mq_map_queue_cpu(set, cpu); return 0; } EXPORT_SYMBOL_GPL(blk_mq_map_queues); diff --git a/block/blk-mq-rdma.c b/block/blk-mq-rdma.c index 996167f1de18..3bce60cd5bcf 100644 --- a/block/blk-mq-rdma.c +++ b/block/blk-mq-rdma.c @@ -14,6 +14,61 @@ #include <linux/blk-mq-rdma.h> #include <rdma/ib_verbs.h> +static int blk_mq_rdma_map_queue(struct blk_mq_tag_set *set, + struct ib_device *dev, int first_vec, unsigned int queue) +{ + const struct cpumask *mask; + unsigned int cpu; + bool mapped = false; + + mask = ib_get_vector_affinity(dev, first_vec + queue); + if (!mask) + return -ENOTSUPP; + + /* map with an unmapped cpu according to affinity mask */ + for_each_cpu(cpu, mask) { + if (set->mq_map[cpu] == UINT_MAX) { + set->mq_map[cpu] = queue; + mapped = true; + break; + } + } + + if (!mapped) { + int n; + + /* map with an unmapped cpu in the same numa node */ + for_each_node(n) { + const struct cpumask *node_cpumask = cpumask_of_node(n); + + if (!cpumask_intersects(mask, node_cpumask)) + continue; + + for_each_cpu(cpu, node_cpumask) { + if (set->mq_map[cpu] == UINT_MAX) { + set->mq_map[cpu] = queue; + mapped = true; + break; + } + } + } + } + + if (!mapped) { + /* map with any unmapped cpu we can find */ + for_each_possible_cpu(cpu) { + if (set->mq_map[cpu] == UINT_MAX) { + set->mq_map[cpu] = queue; + mapped = true; + break; + } + } + } + + WARN_ON_ONCE(!mapped); + return 0; +} + /** * blk_mq_rdma_map_queues - provide a default queue mapping for rdma device * @set: tagset to provide the mapping for @@ -21,31 +76,36 @@ * @first_vec: first interrupt vectors to use for queues (usually 0) * * This function assumes the rdma device @dev has at least as many available - * interrupt vetors as @set has queues. It will then query it's affinity mask - * and built queue mapping that maps a queue to the CPUs that have irq affinity - * for the corresponding vector. + * interrupt vetors as @set has queues. It will then query vector affinity mask + * and attempt to build irq affinity aware queue mappings. If optimal affinity + * aware mapping cannot be acheived for a given queue, we look for any unmapped + * cpu to map it. Lastly, we map naively all other unmapped cpus in the mq_map. * * In case either the driver passed a @dev with less vectors than * @set->nr_hw_queues, or @dev does not provide an affinity mask for a * vector, we fallback to the naive mapping. */ int blk_mq_rdma_map_queues(struct blk_mq_tag_set *set, - struct ib_device *dev, int first_vec) + struct ib_device *dev, int first_vec) { - const struct cpumask *mask; unsigned int queue, cpu; + /* reset cpu mapping */ + for_each_possible_cpu(cpu) + set->mq_map[cpu] = UINT_MAX; + for (queue = 0; queue < set->nr_hw_queues; queue++) { - mask = ib_get_vector_affinity(dev, first_vec + queue); - if (!mask) + if (blk_mq_rdma_map_queue(set, dev, first_vec, queue)) goto fallback; + } - for_each_cpu(cpu, mask) - set->mq_map[cpu] = queue; + /* map any remaining unmapped cpus */ + for_each_possible_cpu(cpu) { + if (set->mq_map[cpu] == UINT_MAX) + blk_mq_map_queue_cpu(set, cpu); } return 0; - fallback: return blk_mq_map_queues(set); } diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index d710e92874cc..6eb09c4de34f 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -285,6 +285,7 @@ int blk_mq_freeze_queue_wait_timeout(struct request_queue *q, unsigned long timeout); int blk_mq_map_queues(struct blk_mq_tag_set *set); +void blk_mq_map_queue_cpu(struct blk_mq_tag_set *set, unsigned int cpu); void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues); void blk_mq_quiesce_queue_nowait(struct request_queue *q);

[v2] block: fix rdma queue mapping

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