diff options
Diffstat (limited to 'drivers/block/null_blk.c')
-rw-r--r-- | drivers/block/null_blk.c | 212 |
1 files changed, 115 insertions, 97 deletions
diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c index f370fc13aea..091b9ea14fe 100644 --- a/drivers/block/null_blk.c +++ b/drivers/block/null_blk.c @@ -1,4 +1,5 @@ #include <linux/module.h> + #include <linux/moduleparam.h> #include <linux/sched.h> #include <linux/fs.h> @@ -59,13 +60,15 @@ enum { NULL_IRQ_NONE = 0, NULL_IRQ_SOFTIRQ = 1, NULL_IRQ_TIMER = 2, +}; +enum { NULL_Q_BIO = 0, NULL_Q_RQ = 1, NULL_Q_MQ = 2, }; -static int submit_queues = 1; +static int submit_queues; module_param(submit_queues, int, S_IRUGO); MODULE_PARM_DESC(submit_queues, "Number of submission queues"); @@ -101,9 +104,9 @@ static int hw_queue_depth = 64; module_param(hw_queue_depth, int, S_IRUGO); MODULE_PARM_DESC(hw_queue_depth, "Queue depth for each hardware queue. Default: 64"); -static bool use_per_node_hctx = true; +static bool use_per_node_hctx = false; module_param(use_per_node_hctx, bool, S_IRUGO); -MODULE_PARM_DESC(use_per_node_hctx, "Use per-node allocation for hardware context queues. Default: true"); +MODULE_PARM_DESC(use_per_node_hctx, "Use per-node allocation for hardware context queues. Default: false"); static void put_tag(struct nullb_queue *nq, unsigned int tag) { @@ -171,18 +174,20 @@ static struct nullb_cmd *alloc_cmd(struct nullb_queue *nq, int can_wait) static void end_cmd(struct nullb_cmd *cmd) { - if (cmd->rq) { - if (queue_mode == NULL_Q_MQ) - blk_mq_end_io(cmd->rq, 0); - else { - INIT_LIST_HEAD(&cmd->rq->queuelist); - blk_end_request_all(cmd->rq, 0); - } - } else if (cmd->bio) + switch (queue_mode) { + case NULL_Q_MQ: + blk_mq_end_io(cmd->rq, 0); + return; + case NULL_Q_RQ: + INIT_LIST_HEAD(&cmd->rq->queuelist); + blk_end_request_all(cmd->rq, 0); + break; + case NULL_Q_BIO: bio_endio(cmd->bio, 0); + break; + } - if (queue_mode != NULL_Q_MQ) - free_cmd(cmd); + free_cmd(cmd); } static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer) @@ -194,6 +199,7 @@ static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer) cq = &per_cpu(completion_queues, smp_processor_id()); while ((entry = llist_del_all(&cq->list)) != NULL) { + entry = llist_reverse_order(entry); do { cmd = container_of(entry, struct nullb_cmd, ll_list); end_cmd(cmd); @@ -220,61 +226,31 @@ static void null_cmd_end_timer(struct nullb_cmd *cmd) static void null_softirq_done_fn(struct request *rq) { - blk_end_request_all(rq, 0); -} - -#ifdef CONFIG_SMP - -static void null_ipi_cmd_end_io(void *data) -{ - struct completion_queue *cq; - struct llist_node *entry, *next; - struct nullb_cmd *cmd; - - cq = &per_cpu(completion_queues, smp_processor_id()); - - entry = llist_del_all(&cq->list); - - while (entry) { - next = entry->next; - cmd = llist_entry(entry, struct nullb_cmd, ll_list); - end_cmd(cmd); - entry = next; - } -} - -static void null_cmd_end_ipi(struct nullb_cmd *cmd) -{ - struct call_single_data *data = &cmd->csd; - int cpu = get_cpu(); - struct completion_queue *cq = &per_cpu(completion_queues, cpu); - - cmd->ll_list.next = NULL; - - if (llist_add(&cmd->ll_list, &cq->list)) { - data->func = null_ipi_cmd_end_io; - data->flags = 0; - __smp_call_function_single(cpu, data, 0); - } - - put_cpu(); + end_cmd(rq->special); } -#endif /* CONFIG_SMP */ - static inline void null_handle_cmd(struct nullb_cmd *cmd) { /* Complete IO by inline, softirq or timer */ switch (irqmode) { - case NULL_IRQ_NONE: - end_cmd(cmd); - break; case NULL_IRQ_SOFTIRQ: -#ifdef CONFIG_SMP - null_cmd_end_ipi(cmd); -#else + switch (queue_mode) { + case NULL_Q_MQ: + blk_mq_complete_request(cmd->rq); + break; + case NULL_Q_RQ: + blk_complete_request(cmd->rq); + break; + case NULL_Q_BIO: + /* + * XXX: no proper submitting cpu information available. + */ + end_cmd(cmd); + break; + } + break; + case NULL_IRQ_NONE: end_cmd(cmd); -#endif break; case NULL_IRQ_TIMER: null_cmd_end_timer(cmd); @@ -346,8 +322,37 @@ static int null_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *rq) static struct blk_mq_hw_ctx *null_alloc_hctx(struct blk_mq_reg *reg, unsigned int hctx_index) { - return kzalloc_node(sizeof(struct blk_mq_hw_ctx), GFP_KERNEL, - hctx_index); + int b_size = DIV_ROUND_UP(reg->nr_hw_queues, nr_online_nodes); + int tip = (reg->nr_hw_queues % nr_online_nodes); + int node = 0, i, n; + + /* + * Split submit queues evenly wrt to the number of nodes. If uneven, + * fill the first buckets with one extra, until the rest is filled with + * no extra. + */ + for (i = 0, n = 1; i < hctx_index; i++, n++) { + if (n % b_size == 0) { + n = 0; + node++; + + tip--; + if (!tip) + b_size = reg->nr_hw_queues / nr_online_nodes; + } + } + + /* + * A node might not be online, therefore map the relative node id to the + * real node id. + */ + for_each_online_node(n) { + if (!node) + break; + node--; + } + + return kzalloc_node(sizeof(struct blk_mq_hw_ctx), GFP_KERNEL, n); } static void null_free_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_index) @@ -355,16 +360,24 @@ static void null_free_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_index) kfree(hctx); } +static void null_init_queue(struct nullb *nullb, struct nullb_queue *nq) +{ + BUG_ON(!nullb); + BUG_ON(!nq); + + init_waitqueue_head(&nq->wait); + nq->queue_depth = nullb->queue_depth; +} + static int null_init_hctx(struct blk_mq_hw_ctx *hctx, void *data, unsigned int index) { struct nullb *nullb = data; struct nullb_queue *nq = &nullb->queues[index]; - init_waitqueue_head(&nq->wait); - nq->queue_depth = nullb->queue_depth; - nullb->nr_queues++; hctx->driver_data = nq; + null_init_queue(nullb, nq); + nullb->nr_queues++; return 0; } @@ -373,6 +386,7 @@ static struct blk_mq_ops null_mq_ops = { .queue_rq = null_queue_rq, .map_queue = blk_mq_map_queue, .init_hctx = null_init_hctx, + .complete = null_softirq_done_fn, }; static struct blk_mq_reg null_mq_reg = { @@ -387,10 +401,7 @@ static void null_del_dev(struct nullb *nullb) list_del_init(&nullb->list); del_gendisk(nullb->disk); - if (queue_mode == NULL_Q_MQ) - blk_mq_free_queue(nullb->q); - else - blk_cleanup_queue(nullb->q); + blk_cleanup_queue(nullb->q); put_disk(nullb->disk); kfree(nullb); } @@ -417,13 +428,13 @@ static int setup_commands(struct nullb_queue *nq) nq->cmds = kzalloc(nq->queue_depth * sizeof(*cmd), GFP_KERNEL); if (!nq->cmds) - return 1; + return -ENOMEM; tag_size = ALIGN(nq->queue_depth, BITS_PER_LONG) / BITS_PER_LONG; nq->tag_map = kzalloc(tag_size * sizeof(unsigned long), GFP_KERNEL); if (!nq->tag_map) { kfree(nq->cmds); - return 1; + return -ENOMEM; } for (i = 0; i < nq->queue_depth; i++) { @@ -454,33 +465,37 @@ static void cleanup_queues(struct nullb *nullb) static int setup_queues(struct nullb *nullb) { - struct nullb_queue *nq; - int i; - - nullb->queues = kzalloc(submit_queues * sizeof(*nq), GFP_KERNEL); + nullb->queues = kzalloc(submit_queues * sizeof(struct nullb_queue), + GFP_KERNEL); if (!nullb->queues) - return 1; + return -ENOMEM; nullb->nr_queues = 0; nullb->queue_depth = hw_queue_depth; - if (queue_mode == NULL_Q_MQ) - return 0; + return 0; +} + +static int init_driver_queues(struct nullb *nullb) +{ + struct nullb_queue *nq; + int i, ret = 0; for (i = 0; i < submit_queues; i++) { nq = &nullb->queues[i]; - init_waitqueue_head(&nq->wait); - nq->queue_depth = hw_queue_depth; - if (setup_commands(nq)) - break; + + null_init_queue(nullb, nq); + + ret = setup_commands(nq); + if (ret) + goto err_queue; nullb->nr_queues++; } - if (i == submit_queues) - return 0; - + return 0; +err_queue: cleanup_queues(nullb); - return 1; + return ret; } static int null_add_dev(void) @@ -518,11 +533,13 @@ static int null_add_dev(void) } else if (queue_mode == NULL_Q_BIO) { nullb->q = blk_alloc_queue_node(GFP_KERNEL, home_node); blk_queue_make_request(nullb->q, null_queue_bio); + init_driver_queues(nullb); } else { nullb->q = blk_init_queue_node(null_request_fn, &nullb->lock, home_node); blk_queue_prep_rq(nullb->q, null_rq_prep_fn); if (nullb->q) blk_queue_softirq_done(nullb->q, null_softirq_done_fn); + init_driver_queues(nullb); } if (!nullb->q) @@ -534,10 +551,7 @@ static int null_add_dev(void) disk = nullb->disk = alloc_disk_node(1, home_node); if (!disk) { queue_fail: - if (queue_mode == NULL_Q_MQ) - blk_mq_free_queue(nullb->q); - else - blk_cleanup_queue(nullb->q); + blk_cleanup_queue(nullb->q); cleanup_queues(nullb); err: kfree(nullb); @@ -571,15 +585,19 @@ static int __init null_init(void) { unsigned int i; -#if !defined(CONFIG_SMP) - if (irqmode == NULL_IRQ_SOFTIRQ) { - pr_warn("null_blk: softirq completions not available.\n"); - pr_warn("null_blk: using direct completions.\n"); - irqmode = NULL_IRQ_NONE; + if (bs > PAGE_SIZE) { + pr_warn("null_blk: invalid block size\n"); + pr_warn("null_blk: defaults block size to %lu\n", PAGE_SIZE); + bs = PAGE_SIZE; } -#endif - if (submit_queues > nr_cpu_ids) + if (queue_mode == NULL_Q_MQ && use_per_node_hctx) { + if (submit_queues < nr_online_nodes) { + pr_warn("null_blk: submit_queues param is set to %u.", + nr_online_nodes); + submit_queues = nr_online_nodes; + } + } else if (submit_queues > nr_cpu_ids) submit_queues = nr_cpu_ids; else if (!submit_queues) submit_queues = 1; |