When isolcpus=io_queue is enabled all hardware queues should run on the housekeeping CPUs only. Thus ignore the affinity mask provided by the driver. Also we can't use blk_mq_map_queues because it will map all CPUs to first hctx unless, the CPU is the same as the hctx has the affinity set to, e.g. 8 CPUs with isolcpus=io_queue,2-3,6-7 config queue mapping for /dev/nvme0n1 hctx0: default 2 3 4 6 7 hctx1: default 5 hctx2: default 0 hctx3: default 1 PCI name is 00:05.0: nvme0n1 irq 57 affinity 0-1 effective 1 is_managed:0 nvme0q0 irq 58 affinity 4 effective 4 is_managed:1 nvme0q1 irq 59 affinity 5 effective 5 is_managed:1 nvme0q2 irq 60 affinity 0 effective 0 is_managed:1 nvme0q3 irq 61 affinity 1 effective 1 is_managed:1 nvme0q4 where as with blk_mq_hk_map_queues we get queue mapping for /dev/nvme0n1 hctx0: default 2 4 hctx1: default 3 5 hctx2: default 0 6 hctx3: default 1 7 PCI name is 00:05.0: nvme0n1 irq 56 affinity 0-1 effective 1 is_managed:0 nvme0q0 irq 61 affinity 4 effective 4 is_managed:1 nvme0q1 irq 62 affinity 5 effective 5 is_managed:1 nvme0q2 irq 63 affinity 0 effective 0 is_managed:1 nvme0q3 irq 64 affinity 1 effective 1 is_managed:1 nvme0q4 Signed-off-by: Daniel Wagner <dwagner@xxxxxxx> --- block/blk-mq-cpumap.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) diff --git a/block/blk-mq-cpumap.c b/block/blk-mq-cpumap.c index c1277763aeeb..7e026c2ffa02 100644 --- a/block/blk-mq-cpumap.c +++ b/block/blk-mq-cpumap.c @@ -60,11 +60,64 @@ unsigned int blk_mq_num_online_queues(unsigned int max_queues) } EXPORT_SYMBOL_GPL(blk_mq_num_online_queues); +static bool blk_mq_hk_map_queues(struct blk_mq_queue_map *qmap) +{ + struct cpumask *hk_masks; + cpumask_var_t isol_mask; + + unsigned int queue, cpu; + + if (!housekeeping_enabled(HK_TYPE_IO_QUEUE)) + return false; + + /* map housekeeping cpus to matching hardware context */ + hk_masks = group_cpus_evenly(qmap->nr_queues); + if (!hk_masks) + goto fallback; + + for (queue = 0; queue < qmap->nr_queues; queue++) { + for_each_cpu(cpu, &hk_masks[queue]) + qmap->mq_map[cpu] = qmap->queue_offset + queue; + } + + kfree(hk_masks); + + /* map isolcpus to hardware context */ + if (!alloc_cpumask_var(&isol_mask, GFP_KERNEL)) + goto fallback; + + queue = 0; + cpumask_andnot(isol_mask, + cpu_possible_mask, + housekeeping_cpumask(HK_TYPE_IO_QUEUE)); + + for_each_cpu(cpu, isol_mask) { + qmap->mq_map[cpu] = qmap->queue_offset + queue; + queue = (queue + 1) % qmap->nr_queues; + } + + free_cpumask_var(isol_mask); + + return true; + +fallback: + /* map all cpus to hardware context ignoring any affinity */ + queue = 0; + for_each_possible_cpu(cpu) { + qmap->mq_map[cpu] = qmap->queue_offset + queue; + queue = (queue + 1) % qmap->nr_queues; + } + return true; +} + void blk_mq_map_queues(struct blk_mq_queue_map *qmap) { const struct cpumask *masks; unsigned int queue, cpu; + if (blk_mq_hk_map_queues(qmap)) + return; + masks = group_cpus_evenly(qmap->nr_queues); if (!masks) { for_each_possible_cpu(cpu) @@ -118,6 +171,9 @@ void blk_mq_dev_map_queues(struct blk_mq_queue_map *qmap, const struct cpumask *mask; unsigned int queue, cpu; + if (blk_mq_hk_map_queues(qmap)) + return; + for (queue = 0; queue < qmap->nr_queues; queue++) { mask = get_queue_affinity(dev_data, dev_off, queue); if (!mask) -- 2.46.0