diff options
Diffstat (limited to 'drivers/nvme/host/tcp.c')
| -rw-r--r-- | drivers/nvme/host/tcp.c | 70 |
1 files changed, 57 insertions, 13 deletions
diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c index 55abfe5e1d25..8305d3c12807 100644 --- a/drivers/nvme/host/tcp.c +++ b/drivers/nvme/host/tcp.c @@ -54,6 +54,8 @@ MODULE_PARM_DESC(tls_handshake_timeout, "nvme TLS handshake timeout in seconds (default 10)"); #endif +static atomic_t nvme_tcp_cpu_queues[NR_CPUS]; + #ifdef CONFIG_DEBUG_LOCK_ALLOC /* lockdep can detect a circular dependency of the form * sk_lock -> mmap_lock (page fault) -> fs locks -> sk_lock @@ -127,6 +129,7 @@ enum nvme_tcp_queue_flags { NVME_TCP_Q_ALLOCATED = 0, NVME_TCP_Q_LIVE = 1, NVME_TCP_Q_POLLING = 2, + NVME_TCP_Q_IO_CPU_SET = 3, }; enum nvme_tcp_recv_state { @@ -1562,23 +1565,56 @@ static bool nvme_tcp_poll_queue(struct nvme_tcp_queue *queue) ctrl->io_queues[HCTX_TYPE_POLL]; } +/** + * Track the number of queues assigned to each cpu using a global per-cpu + * counter and select the least used cpu from the mq_map. Our goal is to spread + * different controllers I/O threads across different cpu cores. + * + * Note that the accounting is not 100% perfect, but we don't need to be, we're + * simply putting our best effort to select the best candidate cpu core that we + * find at any given point. + */ static void nvme_tcp_set_queue_io_cpu(struct nvme_tcp_queue *queue) { struct nvme_tcp_ctrl *ctrl = queue->ctrl; - int qid = nvme_tcp_queue_id(queue); - int n = 0; + struct blk_mq_tag_set *set = &ctrl->tag_set; + int qid = nvme_tcp_queue_id(queue) - 1; + unsigned int *mq_map = NULL; + int cpu, min_queues = INT_MAX, io_cpu; + + if (wq_unbound) + goto out; if (nvme_tcp_default_queue(queue)) - n = qid - 1; + mq_map = set->map[HCTX_TYPE_DEFAULT].mq_map; else if (nvme_tcp_read_queue(queue)) - n = qid - ctrl->io_queues[HCTX_TYPE_DEFAULT] - 1; + mq_map = set->map[HCTX_TYPE_READ].mq_map; else if (nvme_tcp_poll_queue(queue)) - n = qid - ctrl->io_queues[HCTX_TYPE_DEFAULT] - - ctrl->io_queues[HCTX_TYPE_READ] - 1; - if (wq_unbound) - queue->io_cpu = WORK_CPU_UNBOUND; - else - queue->io_cpu = cpumask_next_wrap(n - 1, cpu_online_mask, -1, false); + mq_map = set->map[HCTX_TYPE_POLL].mq_map; + + if (WARN_ON(!mq_map)) + goto out; + + /* Search for the least used cpu from the mq_map */ + io_cpu = WORK_CPU_UNBOUND; + for_each_online_cpu(cpu) { + int num_queues = atomic_read(&nvme_tcp_cpu_queues[cpu]); + + if (mq_map[cpu] != qid) + continue; + if (num_queues < min_queues) { + io_cpu = cpu; + min_queues = num_queues; + } + } + if (io_cpu != WORK_CPU_UNBOUND) { + queue->io_cpu = io_cpu; + atomic_inc(&nvme_tcp_cpu_queues[io_cpu]); + set_bit(NVME_TCP_Q_IO_CPU_SET, &queue->flags); + } +out: + dev_dbg(ctrl->ctrl.device, "queue %d: using cpu %d\n", + qid, queue->io_cpu); } static void nvme_tcp_tls_done(void *data, int status, key_serial_t pskid) @@ -1722,7 +1758,7 @@ static int nvme_tcp_alloc_queue(struct nvme_ctrl *nctrl, int qid, queue->sock->sk->sk_allocation = GFP_ATOMIC; queue->sock->sk->sk_use_task_frag = false; - nvme_tcp_set_queue_io_cpu(queue); + queue->io_cpu = WORK_CPU_UNBOUND; queue->request = NULL; queue->data_remaining = 0; queue->ddgst_remaining = 0; @@ -1844,6 +1880,9 @@ static void nvme_tcp_stop_queue(struct nvme_ctrl *nctrl, int qid) if (!test_bit(NVME_TCP_Q_ALLOCATED, &queue->flags)) return; + if (test_and_clear_bit(NVME_TCP_Q_IO_CPU_SET, &queue->flags)) + atomic_dec(&nvme_tcp_cpu_queues[queue->io_cpu]); + mutex_lock(&queue->queue_lock); if (test_and_clear_bit(NVME_TCP_Q_LIVE, &queue->flags)) __nvme_tcp_stop_queue(queue); @@ -1878,9 +1917,10 @@ static int nvme_tcp_start_queue(struct nvme_ctrl *nctrl, int idx) nvme_tcp_init_recv_ctx(queue); nvme_tcp_setup_sock_ops(queue); - if (idx) + if (idx) { + nvme_tcp_set_queue_io_cpu(queue); ret = nvmf_connect_io_queue(nctrl, idx); - else + } else ret = nvmf_connect_admin_queue(nctrl); if (!ret) { @@ -2856,6 +2896,7 @@ static struct nvmf_transport_ops nvme_tcp_transport = { static int __init nvme_tcp_init_module(void) { unsigned int wq_flags = WQ_MEM_RECLAIM | WQ_HIGHPRI | WQ_SYSFS; + int cpu; BUILD_BUG_ON(sizeof(struct nvme_tcp_hdr) != 8); BUILD_BUG_ON(sizeof(struct nvme_tcp_cmd_pdu) != 72); @@ -2873,6 +2914,9 @@ static int __init nvme_tcp_init_module(void) if (!nvme_tcp_wq) return -ENOMEM; + for_each_possible_cpu(cpu) + atomic_set(&nvme_tcp_cpu_queues[cpu], 0); + nvmf_register_transport(&nvme_tcp_transport); return 0; } |