| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/backing-dev.h> |
| #include <linux/bio.h> |
| #include <linux/blkdev.h> |
| #include <linux/mm.h> |
| #include <linux/init.h> |
| #include <linux/slab.h> |
| #include <linux/workqueue.h> |
| #include <linux/smp.h> |
| #include <linux/llist.h> |
| #include <linux/list_sort.h> |
| #include <linux/cpu.h> |
| #include <linux/cache.h> |
| #include <linux/sched/sysctl.h> |
| #include <linux/delay.h> |
| |
| #include <trace/events/block.h> |
| |
| #include <linux/blk-mq.h> |
| #include "blk.h" |
| #include "blk-mq.h" |
| #include "blk-mq-tag.h" |
| |
| static DEFINE_MUTEX(all_q_mutex); |
| static LIST_HEAD(all_q_list); |
| |
| static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx); |
| |
| static struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q, |
| unsigned int cpu) |
| { |
| return per_cpu_ptr(q->queue_ctx, cpu); |
| } |
| |
| /* |
| * This assumes per-cpu software queueing queues. They could be per-node |
| * as well, for instance. For now this is hardcoded as-is. Note that we don't |
| * care about preemption, since we know the ctx's are persistent. This does |
| * mean that we can't rely on ctx always matching the currently running CPU. |
| */ |
| static struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q) |
| { |
| return __blk_mq_get_ctx(q, get_cpu()); |
| } |
| |
| static void blk_mq_put_ctx(struct blk_mq_ctx *ctx) |
| { |
| put_cpu(); |
| } |
| |
| /* |
| * Check if any of the ctx's have pending work in this hardware queue |
| */ |
| static bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx) |
| { |
| unsigned int i; |
| |
| for (i = 0; i < hctx->nr_ctx_map; i++) |
| if (hctx->ctx_map[i]) |
| return true; |
| |
| return false; |
| } |
| |
| /* |
| * Mark this ctx as having pending work in this hardware queue |
| */ |
| static void blk_mq_hctx_mark_pending(struct blk_mq_hw_ctx *hctx, |
| struct blk_mq_ctx *ctx) |
| { |
| if (!test_bit(ctx->index_hw, hctx->ctx_map)) |
| set_bit(ctx->index_hw, hctx->ctx_map); |
| } |
| |
| static struct request *__blk_mq_alloc_request(struct blk_mq_hw_ctx *hctx, |
| gfp_t gfp, bool reserved) |
| { |
| struct request *rq; |
| unsigned int tag; |
| |
| tag = blk_mq_get_tag(hctx->tags, gfp, reserved); |
| if (tag != BLK_MQ_TAG_FAIL) { |
| rq = hctx->rqs[tag]; |
| rq->tag = tag; |
| |
| return rq; |
| } |
| |
| return NULL; |
| } |
| |
| static int blk_mq_queue_enter(struct request_queue *q) |
| { |
| int ret; |
| |
| __percpu_counter_add(&q->mq_usage_counter, 1, 1000000); |
| smp_wmb(); |
| /* we have problems to freeze the queue if it's initializing */ |
| if (!blk_queue_bypass(q) || !blk_queue_init_done(q)) |
| return 0; |
| |
| __percpu_counter_add(&q->mq_usage_counter, -1, 1000000); |
| |
| spin_lock_irq(q->queue_lock); |
| ret = wait_event_interruptible_lock_irq(q->mq_freeze_wq, |
| !blk_queue_bypass(q) || blk_queue_dying(q), |
| *q->queue_lock); |
| /* inc usage with lock hold to avoid freeze_queue runs here */ |
| if (!ret && !blk_queue_dying(q)) |
| __percpu_counter_add(&q->mq_usage_counter, 1, 1000000); |
| else if (blk_queue_dying(q)) |
| ret = -ENODEV; |
| spin_unlock_irq(q->queue_lock); |
| |
| return ret; |
| } |
| |
| static void blk_mq_queue_exit(struct request_queue *q) |
| { |
| __percpu_counter_add(&q->mq_usage_counter, -1, 1000000); |
| } |
| |
| static void __blk_mq_drain_queue(struct request_queue *q) |
| { |
| while (true) { |
| s64 count; |
| |
| spin_lock_irq(q->queue_lock); |
| count = percpu_counter_sum(&q->mq_usage_counter); |
| spin_unlock_irq(q->queue_lock); |
| |
| if (count == 0) |
| break; |
| blk_mq_run_queues(q, false); |
| msleep(10); |
| } |
| } |
| |
| /* |
| * Guarantee no request is in use, so we can change any data structure of |
| * the queue afterward. |
| */ |
| static void blk_mq_freeze_queue(struct request_queue *q) |
| { |
| bool drain; |
| |
| spin_lock_irq(q->queue_lock); |
| drain = !q->bypass_depth++; |
| queue_flag_set(QUEUE_FLAG_BYPASS, q); |
| spin_unlock_irq(q->queue_lock); |
| |
| if (drain) |
| __blk_mq_drain_queue(q); |
| } |
| |
| void blk_mq_drain_queue(struct request_queue *q) |
| { |
| __blk_mq_drain_queue(q); |
| } |
| |
| static void blk_mq_unfreeze_queue(struct request_queue *q) |
| { |
| bool wake = false; |
| |
| spin_lock_irq(q->queue_lock); |
| if (!--q->bypass_depth) { |
| queue_flag_clear(QUEUE_FLAG_BYPASS, q); |
| wake = true; |
| } |
| WARN_ON_ONCE(q->bypass_depth < 0); |
| spin_unlock_irq(q->queue_lock); |
| if (wake) |
| wake_up_all(&q->mq_freeze_wq); |
| } |
| |
| bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx) |
| { |
| return blk_mq_has_free_tags(hctx->tags); |
| } |
| EXPORT_SYMBOL(blk_mq_can_queue); |
| |
| static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx, |
| struct request *rq, unsigned int rw_flags) |
| { |
| if (blk_queue_io_stat(q)) |
| rw_flags |= REQ_IO_STAT; |
| |
| rq->mq_ctx = ctx; |
| rq->cmd_flags = rw_flags; |
| rq->start_time = jiffies; |
| set_start_time_ns(rq); |
| ctx->rq_dispatched[rw_is_sync(rw_flags)]++; |
| } |
| |
| static struct request *blk_mq_alloc_request_pinned(struct request_queue *q, |
| int rw, gfp_t gfp, |
| bool reserved) |
| { |
| struct request *rq; |
| |
| do { |
| struct blk_mq_ctx *ctx = blk_mq_get_ctx(q); |
| struct blk_mq_hw_ctx *hctx = q->mq_ops->map_queue(q, ctx->cpu); |
| |
| rq = __blk_mq_alloc_request(hctx, gfp & ~__GFP_WAIT, reserved); |
| if (rq) { |
| blk_mq_rq_ctx_init(q, ctx, rq, rw); |
| break; |
| } |
| |
| blk_mq_put_ctx(ctx); |
| if (!(gfp & __GFP_WAIT)) |
| break; |
| |
| __blk_mq_run_hw_queue(hctx); |
| blk_mq_wait_for_tags(hctx->tags); |
| } while (1); |
| |
| return rq; |
| } |
| |
| struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp) |
| { |
| struct request *rq; |
| |
| if (blk_mq_queue_enter(q)) |
| return NULL; |
| |
| rq = blk_mq_alloc_request_pinned(q, rw, gfp, false); |
| if (rq) |
| blk_mq_put_ctx(rq->mq_ctx); |
| return rq; |
| } |
| |
| struct request *blk_mq_alloc_reserved_request(struct request_queue *q, int rw, |
| gfp_t gfp) |
| { |
| struct request *rq; |
| |
| if (blk_mq_queue_enter(q)) |
| return NULL; |
| |
| rq = blk_mq_alloc_request_pinned(q, rw, gfp, true); |
| if (rq) |
| blk_mq_put_ctx(rq->mq_ctx); |
| return rq; |
| } |
| EXPORT_SYMBOL(blk_mq_alloc_reserved_request); |
| |
| /* |
| * Re-init and set pdu, if we have it |
| */ |
| void blk_mq_rq_init(struct blk_mq_hw_ctx *hctx, struct request *rq) |
| { |
| blk_rq_init(hctx->queue, rq); |
| |
| if (hctx->cmd_size) |
| rq->special = blk_mq_rq_to_pdu(rq); |
| } |
| |
| static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, |
| struct blk_mq_ctx *ctx, struct request *rq) |
| { |
| const int tag = rq->tag; |
| struct request_queue *q = rq->q; |
| |
| blk_mq_rq_init(hctx, rq); |
| blk_mq_put_tag(hctx->tags, tag); |
| |
| blk_mq_queue_exit(q); |
| } |
| |
| void blk_mq_free_request(struct request *rq) |
| { |
| struct blk_mq_ctx *ctx = rq->mq_ctx; |
| struct blk_mq_hw_ctx *hctx; |
| struct request_queue *q = rq->q; |
| |
| ctx->rq_completed[rq_is_sync(rq)]++; |
| |
| hctx = q->mq_ops->map_queue(q, ctx->cpu); |
| __blk_mq_free_request(hctx, ctx, rq); |
| } |
| |
| static void blk_mq_bio_endio(struct request *rq, struct bio *bio, int error) |
| { |
| if (error) |
| clear_bit(BIO_UPTODATE, &bio->bi_flags); |
| else if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) |
| error = -EIO; |
| |
| if (unlikely(rq->cmd_flags & REQ_QUIET)) |
| set_bit(BIO_QUIET, &bio->bi_flags); |
| |
| /* don't actually finish bio if it's part of flush sequence */ |
| if (!(rq->cmd_flags & REQ_FLUSH_SEQ)) |
| bio_endio(bio, error); |
| } |
| |
| void blk_mq_end_io(struct request *rq, int error) |
| { |
| struct bio *bio = rq->bio; |
| unsigned int bytes = 0; |
| |
| trace_block_rq_complete(rq->q, rq); |
| |
| while (bio) { |
| struct bio *next = bio->bi_next; |
| |
| bio->bi_next = NULL; |
| bytes += bio->bi_iter.bi_size; |
| blk_mq_bio_endio(rq, bio, error); |
| bio = next; |
| } |
| |
| blk_account_io_completion(rq, bytes); |
| |
| blk_account_io_done(rq); |
| |
| if (rq->end_io) |
| rq->end_io(rq, error); |
| else |
| blk_mq_free_request(rq); |
| } |
| EXPORT_SYMBOL(blk_mq_end_io); |
| |
| static void __blk_mq_complete_request_remote(void *data) |
| { |
| struct request *rq = data; |
| |
| rq->q->softirq_done_fn(rq); |
| } |
| |
| void __blk_mq_complete_request(struct request *rq) |
| { |
| struct blk_mq_ctx *ctx = rq->mq_ctx; |
| int cpu; |
| |
| if (!ctx->ipi_redirect) { |
| rq->q->softirq_done_fn(rq); |
| return; |
| } |
| |
| cpu = get_cpu(); |
| if (cpu != ctx->cpu && cpu_online(ctx->cpu)) { |
| rq->csd.func = __blk_mq_complete_request_remote; |
| rq->csd.info = rq; |
| rq->csd.flags = 0; |
| __smp_call_function_single(ctx->cpu, &rq->csd, 0); |
| } else { |
| rq->q->softirq_done_fn(rq); |
| } |
| put_cpu(); |
| } |
| |
| /** |
| * blk_mq_complete_request - end I/O on a request |
| * @rq: the request being processed |
| * |
| * Description: |
| * Ends all I/O on a request. It does not handle partial completions. |
| * The actual completion happens out-of-order, through a IPI handler. |
| **/ |
| void blk_mq_complete_request(struct request *rq) |
| { |
| if (unlikely(blk_should_fake_timeout(rq->q))) |
| return; |
| if (!blk_mark_rq_complete(rq)) |
| __blk_mq_complete_request(rq); |
| } |
| EXPORT_SYMBOL(blk_mq_complete_request); |
| |
| static void blk_mq_start_request(struct request *rq, bool last) |
| { |
| struct request_queue *q = rq->q; |
| |
| trace_block_rq_issue(q, rq); |
| |
| /* |
| * Just mark start time and set the started bit. Due to memory |
| * ordering, we know we'll see the correct deadline as long as |
| * REQ_ATOMIC_STARTED is seen. |
| */ |
| rq->deadline = jiffies + q->rq_timeout; |
| set_bit(REQ_ATOM_STARTED, &rq->atomic_flags); |
| |
| if (q->dma_drain_size && blk_rq_bytes(rq)) { |
| /* |
| * Make sure space for the drain appears. We know we can do |
| * this because max_hw_segments has been adjusted to be one |
| * fewer than the device can handle. |
| */ |
| rq->nr_phys_segments++; |
| } |
| |
| /* |
| * Flag the last request in the series so that drivers know when IO |
| * should be kicked off, if they don't do it on a per-request basis. |
| * |
| * Note: the flag isn't the only condition drivers should do kick off. |
| * If drive is busy, the last request might not have the bit set. |
| */ |
| if (last) |
| rq->cmd_flags |= REQ_END; |
| } |
| |
| static void blk_mq_requeue_request(struct request *rq) |
| { |
| struct request_queue *q = rq->q; |
| |
| trace_block_rq_requeue(q, rq); |
| clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags); |
| |
| rq->cmd_flags &= ~REQ_END; |
| |
| if (q->dma_drain_size && blk_rq_bytes(rq)) |
| rq->nr_phys_segments--; |
| } |
| |
| struct blk_mq_timeout_data { |
| struct blk_mq_hw_ctx *hctx; |
| unsigned long *next; |
| unsigned int *next_set; |
| }; |
| |
| static void blk_mq_timeout_check(void *__data, unsigned long *free_tags) |
| { |
| struct blk_mq_timeout_data *data = __data; |
| struct blk_mq_hw_ctx *hctx = data->hctx; |
| unsigned int tag; |
| |
| /* It may not be in flight yet (this is where |
| * the REQ_ATOMIC_STARTED flag comes in). The requests are |
| * statically allocated, so we know it's always safe to access the |
| * memory associated with a bit offset into ->rqs[]. |
| */ |
| tag = 0; |
| do { |
| struct request *rq; |
| |
| tag = find_next_zero_bit(free_tags, hctx->queue_depth, tag); |
| if (tag >= hctx->queue_depth) |
| break; |
| |
| rq = hctx->rqs[tag++]; |
| |
| if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) |
| continue; |
| |
| blk_rq_check_expired(rq, data->next, data->next_set); |
| } while (1); |
| } |
| |
| static void blk_mq_hw_ctx_check_timeout(struct blk_mq_hw_ctx *hctx, |
| unsigned long *next, |
| unsigned int *next_set) |
| { |
| struct blk_mq_timeout_data data = { |
| .hctx = hctx, |
| .next = next, |
| .next_set = next_set, |
| }; |
| |
| /* |
| * Ask the tagging code to iterate busy requests, so we can |
| * check them for timeout. |
| */ |
| blk_mq_tag_busy_iter(hctx->tags, blk_mq_timeout_check, &data); |
| } |
| |
| static void blk_mq_rq_timer(unsigned long data) |
| { |
| struct request_queue *q = (struct request_queue *) data; |
| struct blk_mq_hw_ctx *hctx; |
| unsigned long next = 0; |
| int i, next_set = 0; |
| |
| queue_for_each_hw_ctx(q, hctx, i) |
| blk_mq_hw_ctx_check_timeout(hctx, &next, &next_set); |
| |
| if (next_set) |
| mod_timer(&q->timeout, round_jiffies_up(next)); |
| } |
| |
| /* |
| * Reverse check our software queue for entries that we could potentially |
| * merge with. Currently includes a hand-wavy stop count of 8, to not spend |
| * too much time checking for merges. |
| */ |
| static bool blk_mq_attempt_merge(struct request_queue *q, |
| struct blk_mq_ctx *ctx, struct bio *bio) |
| { |
| struct request *rq; |
| int checked = 8; |
| |
| list_for_each_entry_reverse(rq, &ctx->rq_list, queuelist) { |
| int el_ret; |
| |
| if (!checked--) |
| break; |
| |
| if (!blk_rq_merge_ok(rq, bio)) |
| continue; |
| |
| el_ret = blk_try_merge(rq, bio); |
| if (el_ret == ELEVATOR_BACK_MERGE) { |
| if (bio_attempt_back_merge(q, rq, bio)) { |
| ctx->rq_merged++; |
| return true; |
| } |
| break; |
| } else if (el_ret == ELEVATOR_FRONT_MERGE) { |
| if (bio_attempt_front_merge(q, rq, bio)) { |
| ctx->rq_merged++; |
| return true; |
| } |
| break; |
| } |
| } |
| |
| return false; |
| } |
| |
| void blk_mq_add_timer(struct request *rq) |
| { |
| __blk_add_timer(rq, NULL); |
| } |
| |
| /* |
| * Run this hardware queue, pulling any software queues mapped to it in. |
| * Note that this function currently has various problems around ordering |
| * of IO. In particular, we'd like FIFO behaviour on handling existing |
| * items on the hctx->dispatch list. Ignore that for now. |
| */ |
| static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) |
| { |
| struct request_queue *q = hctx->queue; |
| struct blk_mq_ctx *ctx; |
| struct request *rq; |
| LIST_HEAD(rq_list); |
| int bit, queued; |
| |
| if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->flags))) |
| return; |
| |
| hctx->run++; |
| |
| /* |
| * Touch any software queue that has pending entries. |
| */ |
| for_each_set_bit(bit, hctx->ctx_map, hctx->nr_ctx) { |
| clear_bit(bit, hctx->ctx_map); |
| ctx = hctx->ctxs[bit]; |
| BUG_ON(bit != ctx->index_hw); |
| |
| spin_lock(&ctx->lock); |
| list_splice_tail_init(&ctx->rq_list, &rq_list); |
| spin_unlock(&ctx->lock); |
| } |
| |
| /* |
| * If we have previous entries on our dispatch list, grab them |
| * and stuff them at the front for more fair dispatch. |
| */ |
| if (!list_empty_careful(&hctx->dispatch)) { |
| spin_lock(&hctx->lock); |
| if (!list_empty(&hctx->dispatch)) |
| list_splice_init(&hctx->dispatch, &rq_list); |
| spin_unlock(&hctx->lock); |
| } |
| |
| /* |
| * Delete and return all entries from our dispatch list |
| */ |
| queued = 0; |
| |
| /* |
| * Now process all the entries, sending them to the driver. |
| */ |
| while (!list_empty(&rq_list)) { |
| int ret; |
| |
| rq = list_first_entry(&rq_list, struct request, queuelist); |
| list_del_init(&rq->queuelist); |
| |
| blk_mq_start_request(rq, list_empty(&rq_list)); |
| |
| ret = q->mq_ops->queue_rq(hctx, rq); |
| switch (ret) { |
| case BLK_MQ_RQ_QUEUE_OK: |
| queued++; |
| continue; |
| case BLK_MQ_RQ_QUEUE_BUSY: |
| /* |
| * FIXME: we should have a mechanism to stop the queue |
| * like blk_stop_queue, otherwise we will waste cpu |
| * time |
| */ |
| list_add(&rq->queuelist, &rq_list); |
| blk_mq_requeue_request(rq); |
| break; |
| default: |
| pr_err("blk-mq: bad return on queue: %d\n", ret); |
| case BLK_MQ_RQ_QUEUE_ERROR: |
| rq->errors = -EIO; |
| blk_mq_end_io(rq, rq->errors); |
| break; |
| } |
| |
| if (ret == BLK_MQ_RQ_QUEUE_BUSY) |
| break; |
| } |
| |
| if (!queued) |
| hctx->dispatched[0]++; |
| else if (queued < (1 << (BLK_MQ_MAX_DISPATCH_ORDER - 1))) |
| hctx->dispatched[ilog2(queued) + 1]++; |
| |
| /* |
| * Any items that need requeuing? Stuff them into hctx->dispatch, |
| * that is where we will continue on next queue run. |
| */ |
| if (!list_empty(&rq_list)) { |
| spin_lock(&hctx->lock); |
| list_splice(&rq_list, &hctx->dispatch); |
| spin_unlock(&hctx->lock); |
| } |
| } |
| |
| void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) |
| { |
| if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->flags))) |
| return; |
| |
| if (!async) |
| __blk_mq_run_hw_queue(hctx); |
| else { |
| struct request_queue *q = hctx->queue; |
| |
| kblockd_schedule_delayed_work(q, &hctx->delayed_work, 0); |
| } |
| } |
| |
| void blk_mq_run_queues(struct request_queue *q, bool async) |
| { |
| struct blk_mq_hw_ctx *hctx; |
| int i; |
| |
| queue_for_each_hw_ctx(q, hctx, i) { |
| if ((!blk_mq_hctx_has_pending(hctx) && |
| list_empty_careful(&hctx->dispatch)) || |
| test_bit(BLK_MQ_S_STOPPED, &hctx->flags)) |
| continue; |
| |
| blk_mq_run_hw_queue(hctx, async); |
| } |
| } |
| EXPORT_SYMBOL(blk_mq_run_queues); |
| |
| void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx) |
| { |
| cancel_delayed_work(&hctx->delayed_work); |
| set_bit(BLK_MQ_S_STOPPED, &hctx->state); |
| } |
| EXPORT_SYMBOL(blk_mq_stop_hw_queue); |
| |
| void blk_mq_stop_hw_queues(struct request_queue *q) |
| { |
| struct blk_mq_hw_ctx *hctx; |
| int i; |
| |
| queue_for_each_hw_ctx(q, hctx, i) |
| blk_mq_stop_hw_queue(hctx); |
| } |
| EXPORT_SYMBOL(blk_mq_stop_hw_queues); |
| |
| void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx) |
| { |
| clear_bit(BLK_MQ_S_STOPPED, &hctx->state); |
| __blk_mq_run_hw_queue(hctx); |
| } |
| EXPORT_SYMBOL(blk_mq_start_hw_queue); |
| |
| void blk_mq_start_stopped_hw_queues(struct request_queue *q) |
| { |
| struct blk_mq_hw_ctx *hctx; |
| int i; |
| |
| queue_for_each_hw_ctx(q, hctx, i) { |
| if (!test_bit(BLK_MQ_S_STOPPED, &hctx->state)) |
| continue; |
| |
| clear_bit(BLK_MQ_S_STOPPED, &hctx->state); |
| blk_mq_run_hw_queue(hctx, true); |
| } |
| } |
| EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues); |
| |
| static void blk_mq_work_fn(struct work_struct *work) |
| { |
| struct blk_mq_hw_ctx *hctx; |
| |
| hctx = container_of(work, struct blk_mq_hw_ctx, delayed_work.work); |
| __blk_mq_run_hw_queue(hctx); |
| } |
| |
| static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, |
| struct request *rq, bool at_head) |
| { |
| struct blk_mq_ctx *ctx = rq->mq_ctx; |
| |
| trace_block_rq_insert(hctx->queue, rq); |
| |
| if (at_head) |
| list_add(&rq->queuelist, &ctx->rq_list); |
| else |
| list_add_tail(&rq->queuelist, &ctx->rq_list); |
| blk_mq_hctx_mark_pending(hctx, ctx); |
| |
| /* |
| * We do this early, to ensure we are on the right CPU. |
| */ |
| blk_mq_add_timer(rq); |
| } |
| |
| void blk_mq_insert_request(struct request *rq, bool at_head, bool run_queue, |
| bool async) |
| { |
| struct request_queue *q = rq->q; |
| struct blk_mq_hw_ctx *hctx; |
| struct blk_mq_ctx *ctx = rq->mq_ctx, *current_ctx; |
| |
| current_ctx = blk_mq_get_ctx(q); |
| if (!cpu_online(ctx->cpu)) |
| rq->mq_ctx = ctx = current_ctx; |
| |
| hctx = q->mq_ops->map_queue(q, ctx->cpu); |
| |
| if (rq->cmd_flags & (REQ_FLUSH | REQ_FUA) && |
| !(rq->cmd_flags & (REQ_FLUSH_SEQ))) { |
| blk_insert_flush(rq); |
| } else { |
| spin_lock(&ctx->lock); |
| __blk_mq_insert_request(hctx, rq, at_head); |
| spin_unlock(&ctx->lock); |
| } |
| |
| blk_mq_put_ctx(current_ctx); |
| |
| if (run_queue) |
| blk_mq_run_hw_queue(hctx, async); |
| } |
| |
| static void blk_mq_insert_requests(struct request_queue *q, |
| struct blk_mq_ctx *ctx, |
| struct list_head *list, |
| int depth, |
| bool from_schedule) |
| |
| { |
| struct blk_mq_hw_ctx *hctx; |
| struct blk_mq_ctx *current_ctx; |
| |
| trace_block_unplug(q, depth, !from_schedule); |
| |
| current_ctx = blk_mq_get_ctx(q); |
| |
| if (!cpu_online(ctx->cpu)) |
| ctx = current_ctx; |
| hctx = q->mq_ops->map_queue(q, ctx->cpu); |
| |
| /* |
| * preemption doesn't flush plug list, so it's possible ctx->cpu is |
| * offline now |
| */ |
| spin_lock(&ctx->lock); |
| while (!list_empty(list)) { |
| struct request *rq; |
| |
| rq = list_first_entry(list, struct request, queuelist); |
| list_del_init(&rq->queuelist); |
| rq->mq_ctx = ctx; |
| __blk_mq_insert_request(hctx, rq, false); |
| } |
| spin_unlock(&ctx->lock); |
| |
| blk_mq_put_ctx(current_ctx); |
| |
| blk_mq_run_hw_queue(hctx, from_schedule); |
| } |
| |
| static int plug_ctx_cmp(void *priv, struct list_head *a, struct list_head *b) |
| { |
| struct request *rqa = container_of(a, struct request, queuelist); |
| struct request *rqb = container_of(b, struct request, queuelist); |
| |
| return !(rqa->mq_ctx < rqb->mq_ctx || |
| (rqa->mq_ctx == rqb->mq_ctx && |
| blk_rq_pos(rqa) < blk_rq_pos(rqb))); |
| } |
| |
| void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) |
| { |
| struct blk_mq_ctx *this_ctx; |
| struct request_queue *this_q; |
| struct request *rq; |
| LIST_HEAD(list); |
| LIST_HEAD(ctx_list); |
| unsigned int depth; |
| |
| list_splice_init(&plug->mq_list, &list); |
| |
| list_sort(NULL, &list, plug_ctx_cmp); |
| |
| this_q = NULL; |
| this_ctx = NULL; |
| depth = 0; |
| |
| while (!list_empty(&list)) { |
| rq = list_entry_rq(list.next); |
| list_del_init(&rq->queuelist); |
| BUG_ON(!rq->q); |
| if (rq->mq_ctx != this_ctx) { |
| if (this_ctx) { |
| blk_mq_insert_requests(this_q, this_ctx, |
| &ctx_list, depth, |
| from_schedule); |
| } |
| |
| this_ctx = rq->mq_ctx; |
| this_q = rq->q; |
| depth = 0; |
| } |
| |
| depth++; |
| list_add_tail(&rq->queuelist, &ctx_list); |
| } |
| |
| /* |
| * If 'this_ctx' is set, we know we have entries to complete |
| * on 'ctx_list'. Do those. |
| */ |
| if (this_ctx) { |
| blk_mq_insert_requests(this_q, this_ctx, &ctx_list, depth, |
| from_schedule); |
| } |
| } |
| |
| static void blk_mq_bio_to_request(struct request *rq, struct bio *bio) |
| { |
| init_request_from_bio(rq, bio); |
| blk_account_io_start(rq, 1); |
| } |
| |
| static void blk_mq_make_request(struct request_queue *q, struct bio *bio) |
| { |
| struct blk_mq_hw_ctx *hctx; |
| struct blk_mq_ctx *ctx; |
| const int is_sync = rw_is_sync(bio->bi_rw); |
| const int is_flush_fua = bio->bi_rw & (REQ_FLUSH | REQ_FUA); |
| int rw = bio_data_dir(bio); |
| struct request *rq; |
| unsigned int use_plug, request_count = 0; |
| |
| /* |
| * If we have multiple hardware queues, just go directly to |
| * one of those for sync IO. |
| */ |
| use_plug = !is_flush_fua && ((q->nr_hw_queues == 1) || !is_sync); |
| |
| blk_queue_bounce(q, &bio); |
| |
| if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) { |
| bio_endio(bio, -EIO); |
| return; |
| } |
| |
| if (use_plug && blk_attempt_plug_merge(q, bio, &request_count)) |
| return; |
| |
| if (blk_mq_queue_enter(q)) { |
| bio_endio(bio, -EIO); |
| return; |
| } |
| |
| ctx = blk_mq_get_ctx(q); |
| hctx = q->mq_ops->map_queue(q, ctx->cpu); |
| |
| trace_block_getrq(q, bio, rw); |
| rq = __blk_mq_alloc_request(hctx, GFP_ATOMIC, false); |
| if (likely(rq)) |
| blk_mq_rq_ctx_init(q, ctx, rq, rw); |
| else { |
| blk_mq_put_ctx(ctx); |
| trace_block_sleeprq(q, bio, rw); |
| rq = blk_mq_alloc_request_pinned(q, rw, __GFP_WAIT|GFP_ATOMIC, |
| false); |
| ctx = rq->mq_ctx; |
| hctx = q->mq_ops->map_queue(q, ctx->cpu); |
| } |
| |
| hctx->queued++; |
| |
| if (unlikely(is_flush_fua)) { |
| blk_mq_bio_to_request(rq, bio); |
| blk_mq_put_ctx(ctx); |
| blk_insert_flush(rq); |
| goto run_queue; |
| } |
| |
| /* |
| * A task plug currently exists. Since this is completely lockless, |
| * utilize that to temporarily store requests until the task is |
| * either done or scheduled away. |
| */ |
| if (use_plug) { |
| struct blk_plug *plug = current->plug; |
| |
| if (plug) { |
| blk_mq_bio_to_request(rq, bio); |
| if (list_empty(&plug->mq_list)) |
| trace_block_plug(q); |
| else if (request_count >= BLK_MAX_REQUEST_COUNT) { |
| blk_flush_plug_list(plug, false); |
| trace_block_plug(q); |
| } |
| list_add_tail(&rq->queuelist, &plug->mq_list); |
| blk_mq_put_ctx(ctx); |
| return; |
| } |
| } |
| |
| spin_lock(&ctx->lock); |
| |
| if ((hctx->flags & BLK_MQ_F_SHOULD_MERGE) && |
| blk_mq_attempt_merge(q, ctx, bio)) |
| __blk_mq_free_request(hctx, ctx, rq); |
| else { |
| blk_mq_bio_to_request(rq, bio); |
| __blk_mq_insert_request(hctx, rq, false); |
| } |
| |
| spin_unlock(&ctx->lock); |
| blk_mq_put_ctx(ctx); |
| |
| /* |
| * For a SYNC request, send it to the hardware immediately. For an |
| * ASYNC request, just ensure that we run it later on. The latter |
| * allows for merging opportunities and more efficient dispatching. |
| */ |
| run_queue: |
| blk_mq_run_hw_queue(hctx, !is_sync || is_flush_fua); |
| } |
| |
| /* |
| * Default mapping to a software queue, since we use one per CPU. |
| */ |
| struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q, const int cpu) |
| { |
| return q->queue_hw_ctx[q->mq_map[cpu]]; |
| } |
| EXPORT_SYMBOL(blk_mq_map_queue); |
| |
| struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_reg *reg, |
| unsigned int hctx_index) |
| { |
| return kmalloc_node(sizeof(struct blk_mq_hw_ctx), |
| GFP_KERNEL | __GFP_ZERO, reg->numa_node); |
| } |
| EXPORT_SYMBOL(blk_mq_alloc_single_hw_queue); |
| |
| void blk_mq_free_single_hw_queue(struct blk_mq_hw_ctx *hctx, |
| unsigned int hctx_index) |
| { |
| kfree(hctx); |
| } |
| EXPORT_SYMBOL(blk_mq_free_single_hw_queue); |
| |
| static void blk_mq_hctx_notify(void *data, unsigned long action, |
| unsigned int cpu) |
| { |
| struct blk_mq_hw_ctx *hctx = data; |
| struct blk_mq_ctx *ctx; |
| LIST_HEAD(tmp); |
| |
| if (action != CPU_DEAD && action != CPU_DEAD_FROZEN) |
| return; |
| |
| /* |
| * Move ctx entries to new CPU, if this one is going away. |
| */ |
| ctx = __blk_mq_get_ctx(hctx->queue, cpu); |
| |
| spin_lock(&ctx->lock); |
| if (!list_empty(&ctx->rq_list)) { |
| list_splice_init(&ctx->rq_list, &tmp); |
| clear_bit(ctx->index_hw, hctx->ctx_map); |
| } |
| spin_unlock(&ctx->lock); |
| |
| if (list_empty(&tmp)) |
| return; |
| |
| ctx = blk_mq_get_ctx(hctx->queue); |
| spin_lock(&ctx->lock); |
| |
| while (!list_empty(&tmp)) { |
| struct request *rq; |
| |
| rq = list_first_entry(&tmp, struct request, queuelist); |
| rq->mq_ctx = ctx; |
| list_move_tail(&rq->queuelist, &ctx->rq_list); |
| } |
| |
| blk_mq_hctx_mark_pending(hctx, ctx); |
| |
| spin_unlock(&ctx->lock); |
| blk_mq_put_ctx(ctx); |
| } |
| |
| static void blk_mq_init_hw_commands(struct blk_mq_hw_ctx *hctx, |
| void (*init)(void *, struct blk_mq_hw_ctx *, |
| struct request *, unsigned int), |
| void *data) |
| { |
| unsigned int i; |
| |
| for (i = 0; i < hctx->queue_depth; i++) { |
| struct request *rq = hctx->rqs[i]; |
| |
| init(data, hctx, rq, i); |
| } |
| } |
| |
| void blk_mq_init_commands(struct request_queue *q, |
| void (*init)(void *, struct blk_mq_hw_ctx *, |
| struct request *, unsigned int), |
| void *data) |
| { |
| struct blk_mq_hw_ctx *hctx; |
| unsigned int i; |
| |
| queue_for_each_hw_ctx(q, hctx, i) |
| blk_mq_init_hw_commands(hctx, init, data); |
| } |
| EXPORT_SYMBOL(blk_mq_init_commands); |
| |
| static void blk_mq_free_rq_map(struct blk_mq_hw_ctx *hctx) |
| { |
| struct page *page; |
| |
| while (!list_empty(&hctx->page_list)) { |
| page = list_first_entry(&hctx->page_list, struct page, lru); |
| list_del_init(&page->lru); |
| __free_pages(page, page->private); |
| } |
| |
| kfree(hctx->rqs); |
| |
| if (hctx->tags) |
| blk_mq_free_tags(hctx->tags); |
| } |
| |
| static size_t order_to_size(unsigned int order) |
| { |
| size_t ret = PAGE_SIZE; |
| |
| while (order--) |
| ret *= 2; |
| |
| return ret; |
| } |
| |
| static int blk_mq_init_rq_map(struct blk_mq_hw_ctx *hctx, |
| unsigned int reserved_tags, int node) |
| { |
| unsigned int i, j, entries_per_page, max_order = 4; |
| size_t rq_size, left; |
| |
| INIT_LIST_HEAD(&hctx->page_list); |
| |
| hctx->rqs = kmalloc_node(hctx->queue_depth * sizeof(struct request *), |
| GFP_KERNEL, node); |
| if (!hctx->rqs) |
| return -ENOMEM; |
| |
| /* |
| * rq_size is the size of the request plus driver payload, rounded |
| * to the cacheline size |
| */ |
| rq_size = round_up(sizeof(struct request) + hctx->cmd_size, |
| cache_line_size()); |
| left = rq_size * hctx->queue_depth; |
| |
| for (i = 0; i < hctx->queue_depth;) { |
| int this_order = max_order; |
| struct page *page; |
| int to_do; |
| void *p; |
| |
| while (left < order_to_size(this_order - 1) && this_order) |
| this_order--; |
| |
| do { |
| page = alloc_pages_node(node, GFP_KERNEL, this_order); |
| if (page) |
| break; |
| if (!this_order--) |
| break; |
| if (order_to_size(this_order) < rq_size) |
| break; |
| } while (1); |
| |
| if (!page) |
| break; |
| |
| page->private = this_order; |
| list_add_tail(&page->lru, &hctx->page_list); |
| |
| p = page_address(page); |
| entries_per_page = order_to_size(this_order) / rq_size; |
| to_do = min(entries_per_page, hctx->queue_depth - i); |
| left -= to_do * rq_size; |
| for (j = 0; j < to_do; j++) { |
| hctx->rqs[i] = p; |
| blk_mq_rq_init(hctx, hctx->rqs[i]); |
| p += rq_size; |
| i++; |
| } |
| } |
| |
| if (i < (reserved_tags + BLK_MQ_TAG_MIN)) |
| goto err_rq_map; |
| else if (i != hctx->queue_depth) { |
| hctx->queue_depth = i; |
| pr_warn("%s: queue depth set to %u because of low memory\n", |
| __func__, i); |
| } |
| |
| hctx->tags = blk_mq_init_tags(hctx->queue_depth, reserved_tags, node); |
| if (!hctx->tags) { |
| err_rq_map: |
| blk_mq_free_rq_map(hctx); |
| return -ENOMEM; |
| } |
| |
| return 0; |
| } |
| |
| static int blk_mq_init_hw_queues(struct request_queue *q, |
| struct blk_mq_reg *reg, void *driver_data) |
| { |
| struct blk_mq_hw_ctx *hctx; |
| unsigned int i, j; |
| |
| /* |
| * Initialize hardware queues |
| */ |
| queue_for_each_hw_ctx(q, hctx, i) { |
| unsigned int num_maps; |
| int node; |
| |
| node = hctx->numa_node; |
| if (node == NUMA_NO_NODE) |
| node = hctx->numa_node = reg->numa_node; |
| |
| INIT_DELAYED_WORK(&hctx->delayed_work, blk_mq_work_fn); |
| spin_lock_init(&hctx->lock); |
| INIT_LIST_HEAD(&hctx->dispatch); |
| hctx->queue = q; |
| hctx->queue_num = i; |
| hctx->flags = reg->flags; |
| hctx->queue_depth = reg->queue_depth; |
| hctx->cmd_size = reg->cmd_size; |
| |
| blk_mq_init_cpu_notifier(&hctx->cpu_notifier, |
| blk_mq_hctx_notify, hctx); |
| blk_mq_register_cpu_notifier(&hctx->cpu_notifier); |
| |
| if (blk_mq_init_rq_map(hctx, reg->reserved_tags, node)) |
| break; |
| |
| /* |
| * Allocate space for all possible cpus to avoid allocation in |
| * runtime |
| */ |
| hctx->ctxs = kmalloc_node(nr_cpu_ids * sizeof(void *), |
| GFP_KERNEL, node); |
| if (!hctx->ctxs) |
| break; |
| |
| num_maps = ALIGN(nr_cpu_ids, BITS_PER_LONG) / BITS_PER_LONG; |
| hctx->ctx_map = kzalloc_node(num_maps * sizeof(unsigned long), |
| GFP_KERNEL, node); |
| if (!hctx->ctx_map) |
| break; |
| |
| hctx->nr_ctx_map = num_maps; |
| hctx->nr_ctx = 0; |
| |
| if (reg->ops->init_hctx && |
| reg->ops->init_hctx(hctx, driver_data, i)) |
| break; |
| } |
| |
| if (i == q->nr_hw_queues) |
| return 0; |
| |
| /* |
| * Init failed |
| */ |
| queue_for_each_hw_ctx(q, hctx, j) { |
| if (i == j) |
| break; |
| |
| if (reg->ops->exit_hctx) |
| reg->ops->exit_hctx(hctx, j); |
| |
| blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier); |
| blk_mq_free_rq_map(hctx); |
| kfree(hctx->ctxs); |
| } |
| |
| return 1; |
| } |
| |
| static void blk_mq_init_cpu_queues(struct request_queue *q, |
| unsigned int nr_hw_queues) |
| { |
| unsigned int i; |
| |
| for_each_possible_cpu(i) { |
| struct blk_mq_ctx *__ctx = per_cpu_ptr(q->queue_ctx, i); |
| struct blk_mq_hw_ctx *hctx; |
| |
| memset(__ctx, 0, sizeof(*__ctx)); |
| __ctx->cpu = i; |
| spin_lock_init(&__ctx->lock); |
| INIT_LIST_HEAD(&__ctx->rq_list); |
| __ctx->queue = q; |
| |
| /* If the cpu isn't online, the cpu is mapped to first hctx */ |
| hctx = q->mq_ops->map_queue(q, i); |
| hctx->nr_ctx++; |
| |
| if (!cpu_online(i)) |
| continue; |
| |
| /* |
| * Set local node, IFF we have more than one hw queue. If |
| * not, we remain on the home node of the device |
| */ |
| if (nr_hw_queues > 1 && hctx->numa_node == NUMA_NO_NODE) |
| hctx->numa_node = cpu_to_node(i); |
| } |
| } |
| |
| static void blk_mq_map_swqueue(struct request_queue *q) |
| { |
| unsigned int i; |
| struct blk_mq_hw_ctx *hctx; |
| struct blk_mq_ctx *ctx; |
| |
| queue_for_each_hw_ctx(q, hctx, i) { |
| hctx->nr_ctx = 0; |
| } |
| |
| /* |
| * Map software to hardware queues |
| */ |
| queue_for_each_ctx(q, ctx, i) { |
| /* If the cpu isn't online, the cpu is mapped to first hctx */ |
| hctx = q->mq_ops->map_queue(q, i); |
| ctx->index_hw = hctx->nr_ctx; |
| hctx->ctxs[hctx->nr_ctx++] = ctx; |
| } |
| } |
| |
| struct request_queue *blk_mq_init_queue(struct blk_mq_reg *reg, |
| void *driver_data) |
| { |
| struct blk_mq_hw_ctx **hctxs; |
| struct blk_mq_ctx *ctx; |
| struct request_queue *q; |
| int i; |
| |
| if (!reg->nr_hw_queues || |
| !reg->ops->queue_rq || !reg->ops->map_queue || |
| !reg->ops->alloc_hctx || !reg->ops->free_hctx) |
| return ERR_PTR(-EINVAL); |
| |
| if (!reg->queue_depth) |
| reg->queue_depth = BLK_MQ_MAX_DEPTH; |
| else if (reg->queue_depth > BLK_MQ_MAX_DEPTH) { |
| pr_err("blk-mq: queuedepth too large (%u)\n", reg->queue_depth); |
| reg->queue_depth = BLK_MQ_MAX_DEPTH; |
| } |
| |
| if (reg->queue_depth < (reg->reserved_tags + BLK_MQ_TAG_MIN)) |
| return ERR_PTR(-EINVAL); |
| |
| ctx = alloc_percpu(struct blk_mq_ctx); |
| if (!ctx) |
| return ERR_PTR(-ENOMEM); |
| |
| hctxs = kmalloc_node(reg->nr_hw_queues * sizeof(*hctxs), GFP_KERNEL, |
| reg->numa_node); |
| |
| if (!hctxs) |
| goto err_percpu; |
| |
| for (i = 0; i < reg->nr_hw_queues; i++) { |
| hctxs[i] = reg->ops->alloc_hctx(reg, i); |
| if (!hctxs[i]) |
| goto err_hctxs; |
| |
| hctxs[i]->numa_node = NUMA_NO_NODE; |
| hctxs[i]->queue_num = i; |
| } |
| |
| q = blk_alloc_queue_node(GFP_KERNEL, reg->numa_node); |
| if (!q) |
| goto err_hctxs; |
| |
| q->mq_map = blk_mq_make_queue_map(reg); |
| if (!q->mq_map) |
| goto err_map; |
| |
| setup_timer(&q->timeout, blk_mq_rq_timer, (unsigned long) q); |
| blk_queue_rq_timeout(q, 30000); |
| |
| q->nr_queues = nr_cpu_ids; |
| q->nr_hw_queues = reg->nr_hw_queues; |
| |
| q->queue_ctx = ctx; |
| q->queue_hw_ctx = hctxs; |
| |
| q->mq_ops = reg->ops; |
| q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT; |
| |
| q->sg_reserved_size = INT_MAX; |
| |
| blk_queue_make_request(q, blk_mq_make_request); |
| blk_queue_rq_timed_out(q, reg->ops->timeout); |
| if (reg->timeout) |
| blk_queue_rq_timeout(q, reg->timeout); |
| |
| if (reg->ops->complete) |
| blk_queue_softirq_done(q, reg->ops->complete); |
| |
| blk_mq_init_flush(q); |
| blk_mq_init_cpu_queues(q, reg->nr_hw_queues); |
| |
| q->flush_rq = kzalloc(round_up(sizeof(struct request) + reg->cmd_size, |
| cache_line_size()), GFP_KERNEL); |
| if (!q->flush_rq) |
| goto err_hw; |
| |
| if (blk_mq_init_hw_queues(q, reg, driver_data)) |
| goto err_flush_rq; |
| |
| blk_mq_map_swqueue(q); |
| |
| mutex_lock(&all_q_mutex); |
| list_add_tail(&q->all_q_node, &all_q_list); |
| mutex_unlock(&all_q_mutex); |
| |
| return q; |
| |
| err_flush_rq: |
| kfree(q->flush_rq); |
| err_hw: |
| kfree(q->mq_map); |
| err_map: |
| blk_cleanup_queue(q); |
| err_hctxs: |
| for (i = 0; i < reg->nr_hw_queues; i++) { |
| if (!hctxs[i]) |
| break; |
| reg->ops->free_hctx(hctxs[i], i); |
| } |
| kfree(hctxs); |
| err_percpu: |
| free_percpu(ctx); |
| return ERR_PTR(-ENOMEM); |
| } |
| EXPORT_SYMBOL(blk_mq_init_queue); |
| |
| void blk_mq_free_queue(struct request_queue *q) |
| { |
| struct blk_mq_hw_ctx *hctx; |
| int i; |
| |
| queue_for_each_hw_ctx(q, hctx, i) { |
| kfree(hctx->ctx_map); |
| kfree(hctx->ctxs); |
| blk_mq_free_rq_map(hctx); |
| blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier); |
| if (q->mq_ops->exit_hctx) |
| q->mq_ops->exit_hctx(hctx, i); |
| q->mq_ops->free_hctx(hctx, i); |
| } |
| |
| free_percpu(q->queue_ctx); |
| kfree(q->queue_hw_ctx); |
| kfree(q->mq_map); |
| |
| q->queue_ctx = NULL; |
| q->queue_hw_ctx = NULL; |
| q->mq_map = NULL; |
| |
| mutex_lock(&all_q_mutex); |
| list_del_init(&q->all_q_node); |
| mutex_unlock(&all_q_mutex); |
| } |
| |
| /* Basically redo blk_mq_init_queue with queue frozen */ |
| static void blk_mq_queue_reinit(struct request_queue *q) |
| { |
| blk_mq_freeze_queue(q); |
| |
| blk_mq_update_queue_map(q->mq_map, q->nr_hw_queues); |
| |
| /* |
| * redo blk_mq_init_cpu_queues and blk_mq_init_hw_queues. FIXME: maybe |
| * we should change hctx numa_node according to new topology (this |
| * involves free and re-allocate memory, worthy doing?) |
| */ |
| |
| blk_mq_map_swqueue(q); |
| |
| blk_mq_unfreeze_queue(q); |
| } |
| |
| static int blk_mq_queue_reinit_notify(struct notifier_block *nb, |
| unsigned long action, void *hcpu) |
| { |
| struct request_queue *q; |
| |
| /* |
| * Before new mapping is established, hotadded cpu might already start |
| * handling requests. This doesn't break anything as we map offline |
| * CPUs to first hardware queue. We will re-init queue below to get |
| * optimal settings. |
| */ |
| if (action != CPU_DEAD && action != CPU_DEAD_FROZEN && |
| action != CPU_ONLINE && action != CPU_ONLINE_FROZEN) |
| return NOTIFY_OK; |
| |
| mutex_lock(&all_q_mutex); |
| list_for_each_entry(q, &all_q_list, all_q_node) |
| blk_mq_queue_reinit(q); |
| mutex_unlock(&all_q_mutex); |
| return NOTIFY_OK; |
| } |
| |
| static int __init blk_mq_init(void) |
| { |
| blk_mq_cpu_init(); |
| |
| /* Must be called after percpu_counter_hotcpu_callback() */ |
| hotcpu_notifier(blk_mq_queue_reinit_notify, -10); |
| |
| return 0; |
| } |
| subsys_initcall(blk_mq_init); |