diff options
| -rw-r--r-- | block/blk-mq.c | 119 | ||||
| -rw-r--r-- | include/linux/blk-mq.h | 10 |
2 files changed, 99 insertions, 30 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index 526feee..e862c44 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -56,21 +56,40 @@ 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]) + for (i = 0; i < hctx->ctx_map.map_size; i++) + if (hctx->ctx_map.map[i].word) return true; return false; } +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) { - if (!test_bit(ctx->index_hw, hctx->ctx_map)) - set_bit(ctx->index_hw, hctx->ctx_map); + 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); +} + +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); } static struct request *__blk_mq_alloc_request(struct blk_mq_hw_ctx *hctx, @@ -615,6 +634,40 @@ static bool blk_mq_attempt_merge(struct request_queue *q, } /* + * 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.map_size; i++) { + struct blk_align_bitmap *bm = &hctx->ctx_map.map[i]; + unsigned int off, bit; + + if (!bm->word) + continue; + + 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; + + 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); + + bit++; + } while (1); + } +} + +/* * 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 @@ -623,10 +676,9 @@ static bool blk_mq_attempt_merge(struct request_queue *q, 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; + int queued; WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask)); @@ -638,14 +690,7 @@ static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) /* * 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]; - - spin_lock(&ctx->lock); - list_splice_tail_init(&ctx->rq_list, &rq_list); - spin_unlock(&ctx->lock); - } + flush_busy_ctxs(hctx, &rq_list); /* * If we have previous entries on our dispatch list, grab them @@ -659,13 +704,9 @@ static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) } /* - * Delete and return all entries from our dispatch list - */ - queued = 0; - - /* * Now process all the entries, sending them to the driver. */ + queued = 0; while (!list_empty(&rq_list)) { int ret; @@ -1158,7 +1199,7 @@ static void blk_mq_hctx_notify(void *data, unsigned long action, 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); + blk_mq_hctx_clear_pending(hctx, ctx); } spin_unlock(&ctx->lock); @@ -1298,6 +1339,34 @@ 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; + + bitmap->map_size = num_maps; + + 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; +} + static int blk_mq_init_hw_queues(struct request_queue *q, struct blk_mq_tag_set *set) { @@ -1308,7 +1377,6 @@ static int blk_mq_init_hw_queues(struct request_queue *q, * Initialize hardware queues */ queue_for_each_hw_ctx(q, hctx, i) { - unsigned int num_maps; int node; node = hctx->numa_node; @@ -1339,13 +1407,9 @@ static int blk_mq_init_hw_queues(struct request_queue *q, 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) + if (blk_mq_alloc_bitmap(&hctx->ctx_map, node)) break; - hctx->nr_ctx_map = num_maps; hctx->nr_ctx = 0; if (set->ops->init_hctx && @@ -1368,7 +1432,7 @@ static int blk_mq_init_hw_queues(struct request_queue *q, blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier); kfree(hctx->ctxs); - kfree(hctx->ctx_map); + blk_mq_free_bitmap(&hctx->ctx_map); } return 1; @@ -1542,7 +1606,6 @@ void blk_mq_free_queue(struct request_queue *q) int i; queue_for_each_hw_ctx(q, hctx, i) { - kfree(hctx->ctx_map); kfree(hctx->ctxs); blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier); if (q->mq_ops->exit_hctx) diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index f83d15f..952e558 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -11,6 +11,12 @@ struct blk_mq_cpu_notifier { void (*notify)(void *data, unsigned long action, unsigned int cpu); }; +struct blk_mq_ctxmap { + unsigned int map_size; + unsigned int bits_per_word; + struct blk_align_bitmap *map; +}; + struct blk_mq_hw_ctx { struct { spinlock_t lock; @@ -31,8 +37,8 @@ struct blk_mq_hw_ctx { void *driver_data; - unsigned int nr_ctx_map; - unsigned long *ctx_map; + struct blk_mq_ctxmap ctx_map; + unsigned int nr_ctx; struct blk_mq_ctx **ctxs; |
