diff options
Diffstat (limited to 'block')
| -rw-r--r-- | block/Kconfig | 1 | ||||
| -rw-r--r-- | block/bio.c | 3 | ||||
| -rw-r--r-- | block/blk-mq-sysfs.c | 25 | ||||
| -rw-r--r-- | block/blk-mq-tag.c | 503 | ||||
| -rw-r--r-- | block/blk-mq-tag.h | 43 | ||||
| -rw-r--r-- | block/blk-mq.c | 169 | ||||
| -rw-r--r-- | block/blk-mq.h | 11 | ||||
| -rw-r--r-- | block/blk-softirq.c | 27 | ||||
| -rw-r--r-- | block/blk-sysfs.c | 4 | ||||
| -rw-r--r-- | block/blk-throttle.c | 6 | ||||
| -rw-r--r-- | block/cfq-iosched.c | 13 |
11 files changed, 225 insertions, 580 deletions
diff --git a/block/Kconfig b/block/Kconfig index 5155338..1d4d624 100644 --- a/block/Kconfig +++ b/block/Kconfig @@ -4,6 +4,7 @@ menuconfig BLOCK bool "Enable the block layer" if EXPERT default y + select SBITMAP help Provide block layer support for the kernel. diff --git a/block/bio.c b/block/bio.c index a6d279e..db85c57 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1068,7 +1068,7 @@ static int bio_copy_to_iter(struct bio *bio, struct iov_iter iter) return 0; } -static void bio_free_pages(struct bio *bio) +void bio_free_pages(struct bio *bio) { struct bio_vec *bvec; int i; @@ -1076,6 +1076,7 @@ static void bio_free_pages(struct bio *bio) bio_for_each_segment_all(bvec, bio, i) __free_page(bvec->bv_page); } +EXPORT_SYMBOL(bio_free_pages); /** * bio_uncopy_user - finish previously mapped bio diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c index ac5160e..01fb455 100644 --- a/block/blk-mq-sysfs.c +++ b/block/blk-mq-sysfs.c @@ -208,12 +208,14 @@ static ssize_t blk_mq_hw_sysfs_dispatched_show(struct blk_mq_hw_ctx *hctx, page += sprintf(page, "%8u\t%lu\n", 0U, hctx->dispatched[0]); - for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER; i++) { - unsigned long d = 1U << (i - 1); + for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER - 1; i++) { + unsigned int d = 1U << (i - 1); - page += sprintf(page, "%8lu\t%lu\n", d, hctx->dispatched[i]); + page += sprintf(page, "%8u\t%lu\n", d, hctx->dispatched[i]); } + page += sprintf(page, "%8u+\t%lu\n", 1U << (i - 1), + hctx->dispatched[i]); return page - start_page; } @@ -391,9 +393,8 @@ static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx) return ret; } -static void __blk_mq_unregister_disk(struct gendisk *disk) +static void __blk_mq_unregister_dev(struct device *dev, struct request_queue *q) { - struct request_queue *q = disk->queue; struct blk_mq_hw_ctx *hctx; struct blk_mq_ctx *ctx; int i, j; @@ -411,15 +412,15 @@ static void __blk_mq_unregister_disk(struct gendisk *disk) kobject_del(&q->mq_kobj); kobject_put(&q->mq_kobj); - kobject_put(&disk_to_dev(disk)->kobj); + kobject_put(&dev->kobj); q->mq_sysfs_init_done = false; } -void blk_mq_unregister_disk(struct gendisk *disk) +void blk_mq_unregister_dev(struct device *dev, struct request_queue *q) { blk_mq_disable_hotplug(); - __blk_mq_unregister_disk(disk); + __blk_mq_unregister_dev(dev, q); blk_mq_enable_hotplug(); } @@ -441,10 +442,8 @@ static void blk_mq_sysfs_init(struct request_queue *q) } } -int blk_mq_register_disk(struct gendisk *disk) +int blk_mq_register_dev(struct device *dev, struct request_queue *q) { - struct device *dev = disk_to_dev(disk); - struct request_queue *q = disk->queue; struct blk_mq_hw_ctx *hctx; int ret, i; @@ -465,7 +464,7 @@ int blk_mq_register_disk(struct gendisk *disk) } if (ret) - __blk_mq_unregister_disk(disk); + __blk_mq_unregister_dev(dev, q); else q->mq_sysfs_init_done = true; out: @@ -473,7 +472,7 @@ out: return ret; } -EXPORT_SYMBOL_GPL(blk_mq_register_disk); +EXPORT_SYMBOL_GPL(blk_mq_register_dev); void blk_mq_sysfs_unregister(struct request_queue *q) { diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index 2eae3d5..dcf5ce3 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -1,58 +1,24 @@ /* - * Fast and scalable bitmap tagging variant. Uses sparser bitmaps spread - * over multiple cachelines to avoid ping-pong between multiple submitters - * or submitter and completer. Uses rolling wakeups to avoid falling of - * the scaling cliff when we run out of tags and have to start putting - * submitters to sleep. - * - * Uses active queue tracking to support fairer distribution of tags - * between multiple submitters when a shared tag map is used. + * Tag allocation using scalable bitmaps. Uses active queue tracking to support + * fairer distribution of tags between multiple submitters when a shared tag map + * is used. * * Copyright (C) 2013-2014 Jens Axboe */ #include <linux/kernel.h> #include <linux/module.h> -#include <linux/random.h> #include <linux/blk-mq.h> #include "blk.h" #include "blk-mq.h" #include "blk-mq-tag.h" -static bool bt_has_free_tags(struct blk_mq_bitmap_tags *bt) -{ - int i; - - for (i = 0; i < bt->map_nr; i++) { - struct blk_align_bitmap *bm = &bt->map[i]; - int ret; - - ret = find_first_zero_bit(&bm->word, bm->depth); - if (ret < bm->depth) - return true; - } - - return false; -} - bool blk_mq_has_free_tags(struct blk_mq_tags *tags) { if (!tags) return true; - return bt_has_free_tags(&tags->bitmap_tags); -} - -static inline int bt_index_inc(int index) -{ - return (index + 1) & (BT_WAIT_QUEUES - 1); -} - -static inline void bt_index_atomic_inc(atomic_t *index) -{ - int old = atomic_read(index); - int new = bt_index_inc(old); - atomic_cmpxchg(index, old, new); + return sbitmap_any_bit_clear(&tags->bitmap_tags.sb); } /* @@ -72,29 +38,9 @@ bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx) */ void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool include_reserve) { - struct blk_mq_bitmap_tags *bt; - int i, wake_index; - - /* - * Make sure all changes prior to this are visible from other CPUs. - */ - smp_mb(); - bt = &tags->bitmap_tags; - wake_index = atomic_read(&bt->wake_index); - for (i = 0; i < BT_WAIT_QUEUES; i++) { - struct bt_wait_state *bs = &bt->bs[wake_index]; - - if (waitqueue_active(&bs->wait)) - wake_up(&bs->wait); - - wake_index = bt_index_inc(wake_index); - } - - if (include_reserve) { - bt = &tags->breserved_tags; - if (waitqueue_active(&bt->bs[0].wait)) - wake_up(&bt->bs[0].wait); - } + sbitmap_queue_wake_all(&tags->bitmap_tags); + if (include_reserve) + sbitmap_queue_wake_all(&tags->breserved_tags); } /* @@ -118,7 +64,7 @@ void __blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx) * and attempt to provide a fair share of the tag depth for each of them. */ static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx, - struct blk_mq_bitmap_tags *bt) + struct sbitmap_queue *bt) { unsigned int depth, users; @@ -130,7 +76,7 @@ static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx, /* * Don't try dividing an ant */ - if (bt->depth == 1) + if (bt->sb.depth == 1) return true; users = atomic_read(&hctx->tags->active_queues); @@ -140,142 +86,36 @@ static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx, /* * Allow at least some tags */ - depth = max((bt->depth + users - 1) / users, 4U); + depth = max((bt->sb.depth + users - 1) / users, 4U); return atomic_read(&hctx->nr_active) < depth; } -static int __bt_get_word(struct blk_align_bitmap *bm, unsigned int last_tag, - bool nowrap) -{ - int tag, org_last_tag = last_tag; - - while (1) { - tag = find_next_zero_bit(&bm->word, bm->depth, last_tag); - if (unlikely(tag >= bm->depth)) { - /* - * We started with an offset, and we didn't reset the - * offset to 0 in a failure case, so start from 0 to - * exhaust the map. - */ - if (org_last_tag && last_tag && !nowrap) { - last_tag = org_last_tag = 0; - continue; - } - return -1; - } - - if (!test_and_set_bit(tag, &bm->word)) - break; - - last_tag = tag + 1; - if (last_tag >= bm->depth - 1) - last_tag = 0; - } - - return tag; -} - -#define BT_ALLOC_RR(tags) (tags->alloc_policy == BLK_TAG_ALLOC_RR) - -/* - * Straight forward bitmap tag implementation, where each bit is a tag - * (cleared == free, and set == busy). The small twist is using per-cpu - * last_tag caches, which blk-mq stores in the blk_mq_ctx software queue - * contexts. This enables us to drastically limit the space searched, - * without dirtying an extra shared cacheline like we would if we stored - * the cache value inside the shared blk_mq_bitmap_tags structure. On top - * of that, each word of tags is in a separate cacheline. This means that - * multiple users will tend to stick to different cachelines, at least - * until the map is exhausted. - */ -static int __bt_get(struct blk_mq_hw_ctx *hctx, struct blk_mq_bitmap_tags *bt, - unsigned int *tag_cache, struct blk_mq_tags *tags) +static int __bt_get(struct blk_mq_hw_ctx *hctx, struct sbitmap_queue *bt) { - unsigned int last_tag, org_last_tag; - int index, i, tag; - if (!hctx_may_queue(hctx, bt)) return -1; - - last_tag = org_last_tag = *tag_cache; - index = TAG_TO_INDEX(bt, last_tag); - - for (i = 0; i < bt->map_nr; i++) { - tag = __bt_get_word(&bt->map[index], TAG_TO_BIT(bt, last_tag), - BT_ALLOC_RR(tags)); - if (tag != -1) { - tag += (index << bt->bits_per_word); - goto done; - } - - /* - * Jump to next index, and reset the last tag to be the - * first tag of that index - */ - index++; - last_tag = (index << bt->bits_per_word); - - if (index >= bt->map_nr) { - index = 0; - last_tag = 0; - } - } - - *tag_cache = 0; - return -1; - - /* - * Only update the cache from the allocation path, if we ended - * up using the specific cached tag. - */ -done: - if (tag == org_last_tag || unlikely(BT_ALLOC_RR(tags))) { - last_tag = tag + 1; - if (last_tag >= bt->depth - 1) - last_tag = 0; - - *tag_cache = last_tag; - } - - return tag; + return __sbitmap_queue_get(bt); } -static struct bt_wait_state *bt_wait_ptr(struct blk_mq_bitmap_tags *bt, - struct blk_mq_hw_ctx *hctx) +static int bt_get(struct blk_mq_alloc_data *data, struct sbitmap_queue *bt, + struct blk_mq_hw_ctx *hctx, struct blk_mq_tags *tags) { - struct bt_wait_state *bs; - int wait_index; - - if (!hctx) - return &bt->bs[0]; - - wait_index = atomic_read(&hctx->wait_index); - bs = &bt->bs[wait_index]; - bt_index_atomic_inc(&hctx->wait_index); - return bs; -} - -static int bt_get(struct blk_mq_alloc_data *data, - struct blk_mq_bitmap_tags *bt, - struct blk_mq_hw_ctx *hctx, - unsigned int *last_tag, struct blk_mq_tags *tags) -{ - struct bt_wait_state *bs; + struct sbq_wait_state *ws; DEFINE_WAIT(wait); int tag; - tag = __bt_get(hctx, bt, last_tag, tags); + tag = __bt_get(hctx, bt); if (tag != -1) return tag; if (data->flags & BLK_MQ_REQ_NOWAIT) return -1; - bs = bt_wait_ptr(bt, hctx); + ws = bt_wait_ptr(bt, hctx); do { - prepare_to_wait(&bs->wait, &wait, TASK_UNINTERRUPTIBLE); + prepare_to_wait(&ws->wait, &wait, TASK_UNINTERRUPTIBLE); - tag = __bt_get(hctx, bt, last_tag, tags); + tag = __bt_get(hctx, bt); if (tag != -1) break; @@ -292,7 +132,7 @@ static int bt_get(struct blk_mq_alloc_data *data, * Retry tag allocation after running the hardware queue, * as running the queue may also have found completions. */ - tag = __bt_get(hctx, bt, last_tag, tags); + tag = __bt_get(hctx, bt); if (tag != -1) break; @@ -305,15 +145,14 @@ static int bt_get(struct blk_mq_alloc_data *data, if (data->flags & BLK_MQ_REQ_RESERVED) { bt = &data->hctx->tags->breserved_tags; } else { - last_tag = &data->ctx->last_tag; hctx = data->hctx; bt = &hctx->tags->bitmap_tags; } - finish_wait(&bs->wait, &wait); - bs = bt_wait_ptr(bt, hctx); + finish_wait(&ws->wait, &wait); + ws = bt_wait_ptr(bt, hctx); } while (1); - finish_wait(&bs->wait, &wait); + finish_wait(&ws->wait, &wait); return tag; } @@ -322,7 +161,7 @@ static unsigned int __blk_mq_get_tag(struct blk_mq_alloc_data *data) int tag; tag = bt_get(data, &data->hctx->tags->bitmap_tags, data->hctx, - &data->ctx->last_tag, data->hctx->tags); + data->hctx->tags); if (tag >= 0) return tag + data->hctx->tags->nr_reserved_tags; @@ -331,15 +170,15 @@ static unsigned int __blk_mq_get_tag(struct blk_mq_alloc_data *data) static unsigned int __blk_mq_get_reserved_tag(struct blk_mq_alloc_data *data) { - int tag, zero = 0; + int tag; if (unlikely(!data->hctx->tags->nr_reserved_tags)) { WARN_ON_ONCE(1); return BLK_MQ_TAG_FAIL; } - tag = bt_get(data, &data->hctx->tags->breserved_tags, NULL, &zero, - data->hctx->tags); + tag = bt_get(data, &data->hctx->tags->breserved_tags, NULL, + data->hctx->tags); if (tag < 0) return BLK_MQ_TAG_FAIL; @@ -353,55 +192,8 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data) return __blk_mq_get_tag(data); } -static struct bt_wait_state *bt_wake_ptr(struct blk_mq_bitmap_tags *bt) -{ - int i, wake_index; - - wake_index = atomic_read(&bt->wake_index); - for (i = 0; i < BT_WAIT_QUEUES; i++) { - struct bt_wait_state *bs = &bt->bs[wake_index]; - - if (waitqueue_active(&bs->wait)) { - int o = atomic_read(&bt->wake_index); - if (wake_index != o) - atomic_cmpxchg(&bt->wake_index, o, wake_index); - - return bs; - } - - wake_index = bt_index_inc(wake_index); - } - - return NULL; -} - -static void bt_clear_tag(struct blk_mq_bitmap_tags *bt, unsigned int tag) -{ - const int index = TAG_TO_INDEX(bt, tag); - struct bt_wait_state *bs; - int wait_cnt; - - clear_bit(TAG_TO_BIT(bt, tag), &bt->map[index].word); - - /* Ensure that the wait list checks occur after clear_bit(). */ - smp_mb(); - - bs = bt_wake_ptr(bt); - if (!bs) - return; - - wait_cnt = atomic_dec_return(&bs->wait_cnt); - if (unlikely(wait_cnt < 0)) - wait_cnt = atomic_inc_return(&bs->wait_cnt); - if (wait_cnt == 0) { - atomic_add(bt->wake_cnt, &bs->wait_cnt); - bt_index_atomic_inc(&bt->wake_index); - wake_up(&bs->wait); - } -} - -void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, unsigned int tag, - unsigned int *last_tag) +void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, + unsigned int tag) { struct blk_mq_tags *tags = hctx->tags; @@ -409,67 +201,92 @@ void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, unsigned int tag, const int real_tag = tag - tags->nr_reserved_tags; BUG_ON(real_tag >= tags->nr_tags); - bt_clear_tag(&tags->bitmap_tags, real_tag); - if (likely(tags->alloc_policy == BLK_TAG_ALLOC_FIFO)) - *last_tag = real_tag; + sbitmap_queue_clear(&tags->bitmap_tags, real_tag, ctx->cpu); } else { BUG_ON(tag >= tags->nr_reserved_tags); - bt_clear_tag(&tags->breserved_tags, tag); + sbitmap_queue_clear(&tags->breserved_tags, tag, ctx->cpu); } } -static void bt_for_each(struct blk_mq_hw_ctx *hctx, - struct blk_mq_bitmap_tags *bt, unsigned int off, - busy_iter_fn *fn, void *data, bool reserved) +struct bt_iter_data { + struct blk_mq_hw_ctx *hctx; + busy_iter_fn *fn; + void *data; + bool reserved; +}; + +static bool bt_iter(struct sbitmap *bitmap, unsigned int bitnr, void *data) { + struct bt_iter_data *iter_data = data; + struct blk_mq_hw_ctx *hctx = iter_data->hctx; + struct blk_mq_tags *tags = hctx->tags; + bool reserved = iter_data->reserved; struct request *rq; - int bit, i; - for (i = 0; i < bt->map_nr; i++) { - struct blk_align_bitmap *bm = &bt->map[i]; + if (!reserved) + bitnr += tags->nr_reserved_tags; + rq = tags->rqs[bitnr]; - for (bit = find_first_bit(&bm->word, bm->depth); - bit < bm->depth; - bit = find_next_bit(&bm->word, bm->depth, bit + 1)) { - rq = hctx->tags->rqs[off + bit]; - if (rq->q == hctx->queue) - fn(hctx, rq, data, reserved); - } + if (rq->q == hctx->queue) + iter_data->fn(hctx, rq, iter_data->data, reserved); + return true; +} - off += (1 << bt->bits_per_word); - } +static void bt_for_each(struct blk_mq_hw_ctx *hctx, struct sbitmap_queue *bt, + busy_iter_fn *fn, void *data, bool reserved) +{ + struct bt_iter_data iter_data = { + .hctx = hctx, + .fn = fn, + .data = data, + .reserved = reserved, + }; + + sbitmap_for_each_set(&bt->sb, bt_iter, &iter_data); } -static void bt_tags_for_each(struct blk_mq_tags *tags, - struct blk_mq_bitmap_tags *bt, unsigned int off, - busy_tag_iter_fn *fn, void *data, bool reserved) +struct bt_tags_iter_data { + struct blk_mq_tags *tags; + busy_tag_iter_fn *fn; + void *data; + bool reserved; +}; + +static bool bt_tags_iter(struct sbitmap *bitmap, unsigned int bitnr, void *data) { + struct bt_tags_iter_data *iter_data = data; + struct blk_mq_tags *tags = iter_data->tags; + bool reserved = iter_data->reserved; struct request *rq; - int bit, i; - if (!tags->rqs) - return; - for (i = 0; i < bt->map_nr; i++) { - struct blk_align_bitmap *bm = &bt->map[i]; - - for (bit = find_first_bit(&bm->word, bm->depth); - bit < bm->depth; - bit = find_next_bit(&bm->word, bm->depth, bit + 1)) { - rq = tags->rqs[off + bit]; - fn(rq, data, reserved); - } + if (!reserved) + bitnr += tags->nr_reserved_tags; + rq = tags->rqs[bitnr]; - off += (1 << bt->bits_per_word); - } + iter_data->fn(rq, iter_data->data, reserved); + return true; +} + +static void bt_tags_for_each(struct blk_mq_tags *tags, struct sbitmap_queue *bt, + busy_tag_iter_fn *fn, void *data, bool reserved) +{ + struct bt_tags_iter_data iter_data = { + .tags = tags, + .fn = fn, + .data = data, + .reserved = reserved, + }; + + if (tags->rqs) + sbitmap_for_each_set(&bt->sb, bt_tags_iter, &iter_data); } static void blk_mq_all_tag_busy_iter(struct blk_mq_tags *tags, busy_tag_iter_fn *fn, void *priv) { if (tags->nr_reserved_tags) - bt_tags_for_each(tags, &tags->breserved_tags, 0, fn, priv, true); - bt_tags_for_each(tags, &tags->bitmap_tags, tags->nr_reserved_tags, fn, priv, - false); + bt_tags_for_each(tags, &tags->breserved_tags, fn, priv, true); + bt_tags_for_each(tags, &tags->bitmap_tags, fn, priv, false); } void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset, @@ -528,124 +345,40 @@ void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn, continue; if (tags->nr_reserved_tags) - bt_for_each(hctx, &tags->breserved_tags, 0, fn, priv, true); - bt_for_each(hctx, &tags->bitmap_tags, tags->nr_reserved_tags, fn, priv, - false); + bt_for_each(hctx, &tags->breserved_tags, fn, priv, true); + bt_for_each(hctx, &tags->bitmap_tags, fn, priv, false); } } -static unsigned int bt_unused_tags(struct blk_mq_bitmap_tags *bt) +static unsigned int bt_unused_tags(const struct sbitmap_queue *bt) { - unsigned int i, used; - - for (i = 0, used = 0; i < bt->map_nr; i++) { - struct blk_align_bitmap *bm = &bt->map[i]; - - used += bitmap_weight(&bm->word, bm->depth); - } - - return bt->depth - used; + return bt->sb.depth - sbitmap_weight(&bt->sb); } -static void bt_update_count(struct blk_mq_bitmap_tags *bt, - unsigned int depth) +static int bt_alloc(struct sbitmap_queue *bt, unsigned int depth, + bool round_robin, int node) { - unsigned int tags_per_word = 1U << bt->bits_per_word; - unsigned int map_depth = depth; - - if (depth) { - int i; - - for (i = 0; i < bt->map_nr; i++) { - bt->map[i].depth = min(map_depth, tags_per_word); - map_depth -= bt->map[i].depth; - } - } - - bt->wake_cnt = BT_WAIT_BATCH; - if (bt->wake_cnt > depth / BT_WAIT_QUEUES) - bt->wake_cnt = max(1U, depth / BT_WAIT_QUEUES); - - bt->depth = depth; -} - -static int bt_alloc(struct blk_mq_bitmap_tags *bt, unsigned int depth, - int node, bool reserved) -{ - int i; - - bt->bits_per_word = ilog2(BITS_PER_LONG); - - /* - * Depth can be zero for reserved tags, that's not a failure - * condition. - */ - if (depth) { - unsigned int nr, tags_per_word; - - tags_per_word = (1 << bt->bits_per_word); - - /* - * If the tag space is small, shrink the number of tags - * per word so we spread over a few cachelines, at least. - * If less than 4 tags, just forget about it, it's not - * going to work optimally anyway. - */ - if (depth >= 4) { - while (tags_per_word * 4 > depth) { - bt->bits_per_word--; - tags_per_word = (1 << bt->bits_per_word); - } - } - - nr = ALIGN(depth, tags_per_word) / tags_per_word; - bt->map = kzalloc_node(nr * sizeof(struct blk_align_bitmap), - GFP_KERNEL, node); - if (!bt->map) - return -ENOMEM; - - bt->map_nr = nr; - } - - bt->bs = kzalloc(BT_WAIT_QUEUES * sizeof(*bt->bs), GFP_KERNEL); - if (!bt->bs) { - kfree(bt->map); - bt->map = NULL; - return -ENOMEM; - } - - bt_update_count(bt, depth); - - for (i = 0; i < BT_WAIT_QUEUES; i++) { - init_waitqueue_head(&bt->bs[i].wait); - atomic_set(&bt->bs[i].wait_cnt, bt->wake_cnt); - } - - return 0; -} - -static void bt_free(struct blk_mq_bitmap_tags *bt) -{ - kfree(bt->map); - kfree(bt->bs); + return sbitmap_queue_init_node(bt, depth, -1, round_robin, GFP_KERNEL, + node); } static struct blk_mq_tags *blk_mq_init_bitmap_tags(struct blk_mq_tags *tags, int node, int alloc_policy) { unsigned int depth = tags->nr_tags - tags->nr_reserved_tags; + bool round_robin = alloc_policy == BLK_TAG_ALLOC_RR; - tags->alloc_policy = alloc_policy; - - if (bt_alloc(&tags->bitmap_tags, depth, node, false)) - goto enomem; - if (bt_alloc(&tags->breserved_tags, tags->nr_reserved_tags, node, true)) - goto enomem; + if (bt_alloc(&tags->bitmap_tags, depth, round_robin, node)) + goto free_tags; + if (bt_alloc(&tags->breserved_tags, tags->nr_reserved_tags, round_robin, + node)) + goto free_bitmap_tags; return tags; -enomem: - bt_free(&tags->bitmap_tags); +free_bitmap_tags: + sbitmap_queue_free(&tags->bitmap_tags); +free_tags: kfree(tags); return NULL; } @@ -673,18 +406,11 @@ struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags, void blk_mq_free_tags(struct blk_mq_tags *tags) { - bt_free(&tags->bitmap_tags); - bt_free(&tags->breserved_tags); + sbitmap_queue_free(&tags->bitmap_tags); + sbitmap_queue_free(&tags->breserved_tags); kfree(tags); } -void blk_mq_tag_init_last_tag(struct blk_mq_tags *tags, unsigned int *tag) -{ - unsigned int depth = tags->nr_tags - tags->nr_reserved_tags; - - *tag = prandom_u32() % depth; -} - int blk_mq_tag_update_depth(struct blk_mq_tags *tags, unsigned int tdepth) { tdepth -= tags->nr_reserved_tags; @@ -695,7 +421,8 @@ int blk_mq_tag_update_depth(struct blk_mq_tags *tags, unsigned int tdepth) * Don't need (or can't) update reserved tags here, they remain * static and should never need resizing. */ - bt_update_count(&tags->bitmap_tags, tdepth); + sbitmap_queue_resize(&tags->bitmap_tags, tdepth); + blk_mq_tag_wakeup_all(tags, false); return 0; } @@ -739,7 +466,7 @@ ssize_t blk_mq_tag_sysfs_show(struct blk_mq_tags *tags, char *page) page += sprintf(page, "nr_tags=%u, reserved_tags=%u, " "bits_per_word=%u\n", tags->nr_tags, tags->nr_reserved_tags, - tags->bitmap_tags.bits_per_word); + 1U << tags->bitmap_tags.sb.shift); free = bt_unused_tags(&tags->bitmap_tags); res = bt_unused_tags(&tags->breserved_tags); diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h index 5569641..d166273 100644 --- a/block/blk-mq-tag.h +++ b/block/blk-mq-tag.h @@ -3,31 +3,6 @@ #include "blk-mq.h" -enum { - BT_WAIT_QUEUES = 8, - BT_WAIT_BATCH = 8, -}; - -struct bt_wait_state { - atomic_t wait_cnt; - wait_queue_head_t wait; -} ____cacheline_aligned_in_smp; - -#define TAG_TO_INDEX(bt, tag) ((tag) >> (bt)->bits_per_word) -#define TAG_TO_BIT(bt, tag) ((tag) & ((1 << (bt)->bits_per_word) - 1)) - -struct blk_mq_bitmap_tags { - unsigned int depth; - unsigned int wake_cnt; - unsigned int bits_per_word; - - unsigned int map_nr; - struct blk_align_bitmap *map; - - atomic_t wake_index; - struct bt_wait_state *bs; -}; - /* * Tag address space map. */ @@ -37,13 +12,11 @@ struct blk_mq_tags { atomic_t active_queues; - struct blk_mq_bitmap_tags bitmap_tags; - struct blk_mq_bitmap_tags breserved_tags; + struct sbitmap_queue bitmap_tags; + struct sbitmap_queue breserved_tags; struct request **rqs; struct list_head page_list; - - int alloc_policy; }; @@ -51,15 +24,23 @@ extern struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, unsigned int r extern void blk_mq_free_tags(struct blk_mq_tags *tags); extern unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data); -extern void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, unsigned int tag, unsigned int *last_tag); +extern void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, + unsigned int tag); extern bool blk_mq_has_free_tags(struct blk_mq_tags *tags); extern ssize_t blk_mq_tag_sysfs_show(struct blk_mq_tags *tags, char *page); -extern void blk_mq_tag_init_last_tag(struct blk_mq_tags *tags, unsigned int *last_tag); extern int blk_mq_tag_update_depth(struct blk_mq_tags *tags, unsigned int depth); extern void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool); void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn, void *priv); +static inline struct sbq_wait_state *bt_wait_ptr(struct sbitmap_queue *bt, + struct blk_mq_hw_ctx *hctx) +{ + if (!hctx) + return &bt->ws[0]; + return sbq_wait_ptr(bt, &hctx->wait_index); +} + enum { BLK_MQ_TAG_CACHE_MIN = 1, BLK_MQ_TAG_CACHE_MAX = 64, diff --git a/block/blk-mq.c b/block/blk-mq.c index f1c5263..b65f572 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -34,49 +34,28 @@ 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); - /* * 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->ctx_map.size; i++) - if (hctx->ctx_map.map[i].word) - return true; - - return false; + return sbitmap_any_bit_set(&hctx->ctx_map); } -static inline struct blk_align_bitmap *get_bm(struct blk_mq_hw_ctx *hctx, - struct blk_mq_ctx *ctx) -{ - return &hctx->ctx_map.map[ctx->index_hw / hctx->ctx_map.bits_per_word]; -} - -#define CTX_TO_BIT(hctx, ctx) \ - ((ctx)->index_hw & ((hctx)->ctx_map.bits_per_word - 1)) - /* * 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) { - struct blk_align_bitmap *bm = get_bm(hctx, ctx); - - if (!test_bit(CTX_TO_BIT(hctx, ctx), &bm->word)) - set_bit(CTX_TO_BIT(hctx, ctx), &bm->word); + if (!sbitmap_test_bit(&hctx->ctx_map, ctx->index_hw)) + sbitmap_set_bit(&hctx->ctx_map, ctx->index_hw); } static void blk_mq_hctx_clear_pending(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx) { - struct blk_align_bitmap *bm = get_bm(hctx, ctx); - - clear_bit(CTX_TO_BIT(hctx, ctx), &bm->word); + sbitmap_clear_bit(&hctx->ctx_map, ctx->index_hw); } void blk_mq_freeze_queue_start(struct request_queue *q) @@ -247,19 +226,9 @@ struct request *blk_mq_alloc_request(struct request_queue *q, int rw, ctx = blk_mq_get_ctx(q); hctx = blk_mq_map_queue(q, ctx->cpu); blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx); - rq = __blk_mq_alloc_request(&alloc_data, rw, 0); - if (!rq && !(flags & BLK_MQ_REQ_NOWAIT)) { - __blk_mq_run_hw_queue(hctx); - blk_mq_put_ctx(ctx); - - ctx = blk_mq_get_ctx(q); - hctx = blk_mq_map_queue(q, ctx->cpu); - blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx); - rq = __blk_mq_alloc_request(&alloc_data, rw, 0); - ctx = alloc_data.ctx; - } blk_mq_put_ctx(ctx); + if (!rq) { blk_queue_exit(q); return ERR_PTR(-EWOULDBLOCK); @@ -297,17 +266,29 @@ struct request *blk_mq_alloc_request_hctx(struct request_queue *q, int rw, if (ret) return ERR_PTR(ret); + /* + * Check if the hardware context is actually mapped to anything. + * If not tell the caller that it should skip this queue. + */ hctx = q->queue_hw_ctx[hctx_idx]; + if (!blk_mq_hw_queue_mapped(hctx)) { + ret = -EXDEV; + goto out_queue_exit; + } ctx = __blk_mq_get_ctx(q, cpumask_first(hctx->cpumask)); blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx); rq = __blk_mq_alloc_request(&alloc_data, rw, 0); if (!rq) { - blk_queue_exit(q); - return ERR_PTR(-EWOULDBLOCK); + ret = -EWOULDBLOCK; + goto out_queue_exit; } return rq; + +out_queue_exit: + blk_queue_exit(q); + return ERR_PTR(ret); } EXPORT_SYMBOL_GPL(blk_mq_alloc_request_hctx); @@ -322,7 +303,7 @@ static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, rq->cmd_flags = 0; clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags); - blk_mq_put_tag(hctx, tag, &ctx->last_tag); + blk_mq_put_tag(hctx, ctx, tag); blk_queue_exit(q); } @@ -751,38 +732,44 @@ static bool blk_mq_attempt_merge(struct request_queue *q, return false; } +struct flush_busy_ctx_data { + struct blk_mq_hw_ctx *hctx; + struct list_head *list; +}; + +static bool flush_busy_ctx(struct sbitmap *sb, unsigned int bitnr, void *data) +{ + struct flush_busy_ctx_data *flush_data = data; + struct blk_mq_hw_ctx *hctx = flush_data->hctx; + struct blk_mq_ctx *ctx = hctx->ctxs[bitnr]; + + sbitmap_clear_bit(sb, bitnr); + spin_lock(&ctx->lock); + list_splice_tail_init(&ctx->rq_list, flush_data->list); + spin_unlock(&ctx->lock); + return true; +} + /* * Process software queues that have been marked busy, splicing them * to the for-dispatch */ static void flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list) { - struct blk_mq_ctx *ctx; - int i; - - for (i = 0; i < hctx->ctx_map.size; i++) { - struct blk_align_bitmap *bm = &hctx->ctx_map.map[i]; - unsigned int off, bit; - - if (!bm->word) - continue; + struct flush_busy_ctx_data data = { + .hctx = hctx, + .list = list, + }; - bit = 0; - off = i * hctx->ctx_map.bits_per_word; - do { - bit = find_next_bit(&bm->word, bm->depth, bit); - if (bit >= bm->depth) - break; + sbitmap_for_each_set(&hctx->ctx_map, flush_busy_ctx, &data); +} - ctx = hctx->ctxs[bit + off]; - clear_bit(bit, &bm->word); - spin_lock(&ctx->lock); - list_splice_tail_init(&ctx->rq_list, list); - spin_unlock(&ctx->lock); +static inline unsigned int queued_to_index(unsigned int queued) +{ + if (!queued) + return 0; - bit++; - } while (1); - } + return min(BLK_MQ_MAX_DISPATCH_ORDER - 1, ilog2(queued) + 1); } /* @@ -873,10 +860,7 @@ static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) dptr = &driver_list; } - if (!queued) - hctx->dispatched[0]++; - else if (queued < (1 << (BLK_MQ_MAX_DISPATCH_ORDER - 1))) - hctx->dispatched[ilog2(queued) + 1]++; + hctx->dispatched[queued_to_index(queued)]++; /* * Any items that need requeuing? Stuff them into hctx->dispatch, @@ -932,7 +916,7 @@ void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) !blk_mq_hw_queue_mapped(hctx))) return; - if (!async) { + if (!async && !(hctx->flags & BLK_MQ_F_BLOCKING)) { int cpu = get_cpu(); if (cpumask_test_cpu(cpu, hctx->cpumask)) { __blk_mq_run_hw_queue(hctx); @@ -1230,20 +1214,8 @@ static struct request *blk_mq_map_request(struct request_queue *q, op_flags |= REQ_SYNC; trace_block_getrq(q, bio, op); - blk_mq_set_alloc_data(&alloc_data, q, BLK_MQ_REQ_NOWAIT, ctx, hctx); + blk_mq_set_alloc_data(&alloc_data, q, 0, ctx, hctx); rq = __blk_mq_alloc_request(&alloc_data, op, op_flags); - if (unlikely(!rq)) { - __blk_mq_run_hw_queue(hctx); - blk_mq_put_ctx(ctx); - trace_block_sleeprq(q, bio, op); - - ctx = blk_mq_get_ctx(q); - hctx = blk_mq_map_queue(q, ctx->cpu); - blk_mq_set_alloc_data(&alloc_data, q, 0, ctx, hctx); - rq = __blk_mq_alloc_request(&alloc_data, op, op_flags); - ctx = alloc_data.ctx; - hctx = alloc_data.hctx; - } hctx->queued++; data->hctx = hctx; @@ -1586,32 +1558,6 @@ fail: return NULL; } -static void blk_mq_free_bitmap(struct blk_mq_ctxmap *bitmap) -{ - kfree(bitmap->map); -} - -static int blk_mq_alloc_bitmap(struct blk_mq_ctxmap *bitmap, int node) -{ - unsigned int bpw = 8, total, num_maps, i; - - bitmap->bits_per_word = bpw; - - num_maps = ALIGN(nr_cpu_ids, bpw) / bpw; - bitmap->map = kzalloc_node(num_maps * sizeof(struct blk_align_bitmap), - GFP_KERNEL, node); - if (!bitmap->map) - return -ENOMEM; - - total = nr_cpu_ids; - for (i = 0; i < num_maps; i++) { - bitmap->map[i].depth = min(total, bitmap->bits_per_word); - total -= bitmap->map[i].depth; - } - - return 0; -} - /* * 'cpu' is going away. splice any existing rq_list entries from this * software queue to the hw queue dispatch list, and ensure that it @@ -1677,7 +1623,7 @@ static void blk_mq_exit_hctx(struct request_queue *q, blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier); blk_free_flush_queue(hctx->fq); - blk_mq_free_bitmap(&hctx->ctx_map); + sbitmap_free(&hctx->ctx_map); } static void blk_mq_exit_hw_queues(struct request_queue *q, @@ -1737,7 +1683,8 @@ static int blk_mq_init_hctx(struct request_queue *q, if (!hctx->ctxs) goto unregister_cpu_notifier; - if (blk_mq_alloc_bitmap(&hctx->ctx_map, node)) + if (sbitmap_init_node(&hctx->ctx_map, nr_cpu_ids, ilog2(8), GFP_KERNEL, + node)) goto free_ctxs; hctx->nr_ctx = 0; @@ -1764,7 +1711,7 @@ static int blk_mq_init_hctx(struct request_queue *q, if (set->ops->exit_hctx) set->ops->exit_hctx(hctx, hctx_idx); free_bitmap: - blk_mq_free_bitmap(&hctx->ctx_map); + sbitmap_free(&hctx->ctx_map); free_ctxs: kfree(hctx->ctxs); unregister_cpu_notifier: @@ -1840,8 +1787,6 @@ static void blk_mq_map_swqueue(struct request_queue *q, mutex_unlock(&q->sysfs_lock); queue_for_each_hw_ctx(q, hctx, i) { - struct blk_mq_ctxmap *map = &hctx->ctx_map; - /* * If no software queues are mapped to this hardware queue, * disable it and free the request entries. @@ -1866,7 +1811,7 @@ static void blk_mq_map_swqueue(struct request_queue *q, * This is more accurate and more efficient than looping * over all possibly mapped software queues. */ - map->size = DIV_ROUND_UP(hctx->nr_ctx, map->bits_per_word); + sbitmap_resize(&hctx->ctx_map, hctx->nr_ctx); /* * Initialize batch roundrobin counts diff --git a/block/blk-mq.h b/block/blk-mq.h index c92bb7d..df6474c 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -12,8 +12,6 @@ struct blk_mq_ctx { unsigned int cpu; unsigned int index_hw; - unsigned int last_tag ____cacheline_aligned_in_smp; - /* incremented at dispatch time */ unsigned long rq_dispatched[2]; unsigned long rq_merged; @@ -67,15 +65,6 @@ extern void blk_mq_rq_timed_out(struct request *req, bool reserved); void blk_mq_release(struct request_queue *q); -/* - * Basic implementation of sparser bitmap, allowing the user to spread - * the bits over more cachelines. - */ -struct blk_align_bitmap { - unsigned long word; - unsigned long depth; -} ____cacheline_aligned_in_smp; - static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q, unsigned int cpu) { diff --git a/block/blk-softirq.c b/block/blk-softirq.c index 53b1737..96631e6 100644 --- a/block/blk-softirq.c +++ b/block/blk-softirq.c @@ -78,30 +78,21 @@ static int raise_blk_irq(int cpu, struct request *rq) } #endif -static int blk_cpu_notify(struct notifier_block *self, unsigned long action, - void *hcpu) +static int blk_softirq_cpu_dead(unsigned int cpu) { /* * If a CPU goes away, splice its entries to the current CPU * and trigger a run of the softirq */ - if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) { - int cpu = (unsigned long) hcpu; - - local_irq_disable(); - list_splice_init(&per_cpu(blk_cpu_done, cpu), - this_cpu_ptr(&blk_cpu_done)); - raise_softirq_irqoff(BLOCK_SOFTIRQ); - local_irq_enable(); - } + local_irq_disable(); + list_splice_init(&per_cpu(blk_cpu_done, cpu), + this_cpu_ptr(&blk_cpu_done)); + raise_softirq_irqoff(BLOCK_SOFTIRQ); + local_irq_enable(); - return NOTIFY_OK; + return 0; } -static struct notifier_block blk_cpu_notifier = { - .notifier_call = blk_cpu_notify, -}; - void __blk_complete_request(struct request *req) { int ccpu, cpu; @@ -180,7 +171,9 @@ static __init int blk_softirq_init(void) INIT_LIST_HEAD(&per_cpu(blk_cpu_done, i)); open_softirq(BLOCK_SOFTIRQ, blk_done_softirq); - register_hotcpu_notifier(&blk_cpu_notifier); + cpuhp_setup_state_nocalls(CPUHP_BLOCK_SOFTIRQ_DEAD, + "block/softirq:dead", NULL, + blk_softirq_cpu_dead); return 0; } subsys_initcall(blk_softirq_init); diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index f87a7e7..9cc8d7c 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -704,7 +704,7 @@ int blk_register_queue(struct gendisk *disk) kobject_uevent(&q->kobj, KOBJ_ADD); if (q->mq_ops) - blk_mq_register_disk(disk); + blk_mq_register_dev(dev, q); if (!q->request_fn) return 0; @@ -729,7 +729,7 @@ void blk_unregister_queue(struct gendisk *disk) return; if (q->mq_ops) - blk_mq_unregister_disk(disk); + blk_mq_unregister_dev(disk_to_dev(disk), q); if (q->request_fn) elv_unregister_queue(q); diff --git a/block/blk-throttle.c b/block/blk-throttle.c index f1aba26..a3ea826 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -780,9 +780,11 @@ static bool tg_may_dispatch(struct throtl_grp *tg, struct bio *bio, /* * If previous slice expired, start a new one otherwise renew/extend * existing slice to make sure it is at least throtl_slice interval - * long since now. + * long since now. New slice is started only for empty throttle group. + * If there is queued bio, that means there should be an active + * slice and it should be extended instead. */ - if (throtl_slice_used(tg, rw)) + if (throtl_slice_used(tg, rw) && !(tg->service_queue.nr_queued[rw])) throtl_start_new_slice(tg, rw); else { if (time_before(tg->slice_end[rw], jiffies + throtl_slice)) diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index cc2f6db..5e24d88 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -3042,7 +3042,6 @@ static struct request *cfq_check_fifo(struct cfq_queue *cfqq) if (ktime_get_ns() < rq->fifo_time) rq = NULL; - cfq_log_cfqq(cfqq->cfqd, cfqq, "fifo=%p", rq); return rq; } @@ -3420,6 +3419,9 @@ static bool cfq_may_dispatch(struct cfq_data *cfqd, struct cfq_queue *cfqq) { unsigned int max_dispatch; + if (cfq_cfqq_must_dispatch(cfqq)) + return true; + /* * Drain async requests before we start sync IO */ @@ -3511,15 +3513,20 @@ static bool cfq_dispatch_request(struct cfq_data *cfqd, struct cfq_queue *cfqq) BUG_ON(RB_EMPTY_ROOT(&cfqq->sort_list)); + rq = cfq_check_fifo(cfqq); + if (rq) + cfq_mark_cfqq_must_dispatch(cfqq); + if (!cfq_may_dispatch(cfqd, cfqq)) return false; /* * follow expired path, else get first next available */ - rq = cfq_check_fifo(cfqq); if (!rq) rq = cfqq->next_rq; + else + cfq_log_cfqq(cfqq->cfqd, cfqq, "fifo=%p", rq); /* * insert request into driver dispatch list @@ -3989,7 +3996,7 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, * if the new request is sync, but the currently running queue is * not, let the sync request have priority. */ - if (rq_is_sync(rq) && !cfq_cfqq_sync(cfqq)) + if (rq_is_sync(rq) && !cfq_cfqq_sync(cfqq) && !cfq_cfqq_must_dispatch(cfqq)) return true; /* |