diff options
| -rw-r--r-- | block/kyber-iosched.c | 190 |
1 files changed, 158 insertions, 32 deletions
diff --git a/block/kyber-iosched.c b/block/kyber-iosched.c index 5b33dc394cc7..a1660bafc912 100644 --- a/block/kyber-iosched.c +++ b/block/kyber-iosched.c @@ -72,6 +72,19 @@ static const unsigned int kyber_batch_size[] = { [KYBER_OTHER] = 8, }; +/* + * There is a same mapping between ctx & hctx and kcq & khd, + * we use request->mq_ctx->index_hw to index the kcq in khd. + */ +struct kyber_ctx_queue { + /* + * Used to ensure operations on rq_list and kcq_map to be an atmoic one. + * Also protect the rqs on rq_list when merge. + */ + spinlock_t lock; + struct list_head rq_list[KYBER_NUM_DOMAINS]; +} ____cacheline_aligned_in_smp; + struct kyber_queue_data { struct request_queue *q; @@ -99,6 +112,8 @@ struct kyber_hctx_data { struct list_head rqs[KYBER_NUM_DOMAINS]; unsigned int cur_domain; unsigned int batching; + struct kyber_ctx_queue *kcqs; + struct sbitmap kcq_map[KYBER_NUM_DOMAINS]; wait_queue_entry_t domain_wait[KYBER_NUM_DOMAINS]; struct sbq_wait_state *domain_ws[KYBER_NUM_DOMAINS]; atomic_t wait_index[KYBER_NUM_DOMAINS]; @@ -107,10 +122,8 @@ struct kyber_hctx_data { static int kyber_domain_wake(wait_queue_entry_t *wait, unsigned mode, int flags, void *key); -static int rq_sched_domain(const struct request *rq) +static unsigned int kyber_sched_domain(unsigned int op) { - unsigned int op = rq->cmd_flags; - if ((op & REQ_OP_MASK) == REQ_OP_READ) return KYBER_READ; else if ((op & REQ_OP_MASK) == REQ_OP_WRITE && op_is_sync(op)) @@ -284,6 +297,11 @@ static unsigned int kyber_sched_tags_shift(struct kyber_queue_data *kqd) return kqd->q->queue_hw_ctx[0]->sched_tags->bitmap_tags.sb.shift; } +static int kyber_bucket_fn(const struct request *rq) +{ + return kyber_sched_domain(rq->cmd_flags); +} + static struct kyber_queue_data *kyber_queue_data_alloc(struct request_queue *q) { struct kyber_queue_data *kqd; @@ -297,7 +315,7 @@ static struct kyber_queue_data *kyber_queue_data_alloc(struct request_queue *q) goto err; kqd->q = q; - kqd->cb = blk_stat_alloc_callback(kyber_stat_timer_fn, rq_sched_domain, + kqd->cb = blk_stat_alloc_callback(kyber_stat_timer_fn, kyber_bucket_fn, KYBER_NUM_DOMAINS, kqd); if (!kqd->cb) goto err_kqd; @@ -376,6 +394,15 @@ static void kyber_exit_sched(struct elevator_queue *e) kfree(kqd); } +static void kyber_ctx_queue_init(struct kyber_ctx_queue *kcq) +{ + unsigned int i; + + spin_lock_init(&kcq->lock); + for (i = 0; i < KYBER_NUM_DOMAINS; i++) + INIT_LIST_HEAD(&kcq->rq_list[i]); +} + static int kyber_init_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx) { struct kyber_queue_data *kqd = hctx->queue->elevator->elevator_data; @@ -386,6 +413,24 @@ static int kyber_init_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx) if (!khd) return -ENOMEM; + khd->kcqs = kmalloc_array_node(hctx->nr_ctx, + sizeof(struct kyber_ctx_queue), + GFP_KERNEL, hctx->numa_node); + if (!khd->kcqs) + goto err_khd; + + for (i = 0; i < hctx->nr_ctx; i++) + kyber_ctx_queue_init(&khd->kcqs[i]); + + for (i = 0; i < KYBER_NUM_DOMAINS; i++) { + if (sbitmap_init_node(&khd->kcq_map[i], hctx->nr_ctx, + ilog2(8), GFP_KERNEL, hctx->numa_node)) { + while (--i >= 0) + sbitmap_free(&khd->kcq_map[i]); + goto err_kcqs; + } + } + spin_lock_init(&khd->lock); for (i = 0; i < KYBER_NUM_DOMAINS; i++) { @@ -405,10 +450,22 @@ static int kyber_init_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx) kqd->async_depth); return 0; + +err_kcqs: + kfree(khd->kcqs); +err_khd: + kfree(khd); + return -ENOMEM; } static void kyber_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx) { + struct kyber_hctx_data *khd = hctx->sched_data; + int i; + + for (i = 0; i < KYBER_NUM_DOMAINS; i++) + sbitmap_free(&khd->kcq_map[i]); + kfree(khd->kcqs); kfree(hctx->sched_data); } @@ -430,7 +487,7 @@ static void rq_clear_domain_token(struct kyber_queue_data *kqd, nr = rq_get_domain_token(rq); if (nr != -1) { - sched_domain = rq_sched_domain(rq); + sched_domain = kyber_sched_domain(rq->cmd_flags); sbitmap_queue_clear(&kqd->domain_tokens[sched_domain], nr, rq->mq_ctx->cpu); } @@ -449,11 +506,51 @@ static void kyber_limit_depth(unsigned int op, struct blk_mq_alloc_data *data) } } +static bool kyber_bio_merge(struct blk_mq_hw_ctx *hctx, struct bio *bio) +{ + struct kyber_hctx_data *khd = hctx->sched_data; + struct blk_mq_ctx *ctx = blk_mq_get_ctx(hctx->queue); + struct kyber_ctx_queue *kcq = &khd->kcqs[ctx->index_hw]; + unsigned int sched_domain = kyber_sched_domain(bio->bi_opf); + struct list_head *rq_list = &kcq->rq_list[sched_domain]; + bool merged; + + spin_lock(&kcq->lock); + merged = blk_mq_bio_list_merge(hctx->queue, rq_list, bio); + spin_unlock(&kcq->lock); + blk_mq_put_ctx(ctx); + + return merged; +} + static void kyber_prepare_request(struct request *rq, struct bio *bio) { rq_set_domain_token(rq, -1); } +static void kyber_insert_requests(struct blk_mq_hw_ctx *hctx, + struct list_head *rq_list, bool at_head) +{ + struct kyber_hctx_data *khd = hctx->sched_data; + struct request *rq, *next; + + list_for_each_entry_safe(rq, next, rq_list, queuelist) { + unsigned int sched_domain = kyber_sched_domain(rq->cmd_flags); + struct kyber_ctx_queue *kcq = &khd->kcqs[rq->mq_ctx->index_hw]; + struct list_head *head = &kcq->rq_list[sched_domain]; + + spin_lock(&kcq->lock); + if (at_head) + list_move(&rq->queuelist, head); + else + list_move_tail(&rq->queuelist, head); + sbitmap_set_bit(&khd->kcq_map[sched_domain], + rq->mq_ctx->index_hw); + blk_mq_sched_request_inserted(rq); + spin_unlock(&kcq->lock); + } +} + static void kyber_finish_request(struct request *rq) { struct kyber_queue_data *kqd = rq->q->elevator->elevator_data; @@ -472,7 +569,7 @@ static void kyber_completed_request(struct request *rq) * Check if this request met our latency goal. If not, quickly gather * some statistics and start throttling. */ - sched_domain = rq_sched_domain(rq); + sched_domain = kyber_sched_domain(rq->cmd_flags); switch (sched_domain) { case KYBER_READ: target = kqd->read_lat_nsec; @@ -498,19 +595,38 @@ static void kyber_completed_request(struct request *rq) blk_stat_activate_msecs(kqd->cb, 10); } -static void kyber_flush_busy_ctxs(struct kyber_hctx_data *khd, - struct blk_mq_hw_ctx *hctx) +struct flush_kcq_data { + struct kyber_hctx_data *khd; + unsigned int sched_domain; + struct list_head *list; +}; + +static bool flush_busy_kcq(struct sbitmap *sb, unsigned int bitnr, void *data) { - LIST_HEAD(rq_list); - struct request *rq, *next; + struct flush_kcq_data *flush_data = data; + struct kyber_ctx_queue *kcq = &flush_data->khd->kcqs[bitnr]; - blk_mq_flush_busy_ctxs(hctx, &rq_list); - list_for_each_entry_safe(rq, next, &rq_list, queuelist) { - unsigned int sched_domain; + spin_lock(&kcq->lock); + list_splice_tail_init(&kcq->rq_list[flush_data->sched_domain], + flush_data->list); + sbitmap_clear_bit(sb, bitnr); + spin_unlock(&kcq->lock); - sched_domain = rq_sched_domain(rq); - list_move_tail(&rq->queuelist, &khd->rqs[sched_domain]); - } + return true; +} + +static void kyber_flush_busy_kcqs(struct kyber_hctx_data *khd, + unsigned int sched_domain, + struct list_head *list) +{ + struct flush_kcq_data data = { + .khd = khd, + .sched_domain = sched_domain, + .list = list, + }; + + sbitmap_for_each_set(&khd->kcq_map[sched_domain], + flush_busy_kcq, &data); } static int kyber_domain_wake(wait_queue_entry_t *wait, unsigned mode, int flags, @@ -573,26 +689,23 @@ static int kyber_get_domain_token(struct kyber_queue_data *kqd, static struct request * kyber_dispatch_cur_domain(struct kyber_queue_data *kqd, struct kyber_hctx_data *khd, - struct blk_mq_hw_ctx *hctx, - bool *flushed) + struct blk_mq_hw_ctx *hctx) { struct list_head *rqs; struct request *rq; int nr; rqs = &khd->rqs[khd->cur_domain]; - rq = list_first_entry_or_null(rqs, struct request, queuelist); /* - * If there wasn't already a pending request and we haven't flushed the - * software queues yet, flush the software queues and check again. + * If we already have a flushed request, then we just need to get a + * token for it. Otherwise, if there are pending requests in the kcqs, + * flush the kcqs, but only if we can get a token. If not, we should + * leave the requests in the kcqs so that they can be merged. Note that + * khd->lock serializes the flushes, so if we observed any bit set in + * the kcq_map, we will always get a request. */ - if (!rq && !*flushed) { - kyber_flush_busy_ctxs(khd, hctx); - *flushed = true; - rq = list_first_entry_or_null(rqs, struct request, queuelist); - } - + rq = list_first_entry_or_null(rqs, struct request, queuelist); if (rq) { nr = kyber_get_domain_token(kqd, khd, hctx); if (nr >= 0) { @@ -601,6 +714,16 @@ kyber_dispatch_cur_domain(struct kyber_queue_data *kqd, list_del_init(&rq->queuelist); return rq; } + } else if (sbitmap_any_bit_set(&khd->kcq_map[khd->cur_domain])) { + nr = kyber_get_domain_token(kqd, khd, hctx); + if (nr >= 0) { + kyber_flush_busy_kcqs(khd, khd->cur_domain, rqs); + rq = list_first_entry(rqs, struct request, queuelist); + khd->batching++; + rq_set_domain_token(rq, nr); + list_del_init(&rq->queuelist); + return rq; + } } /* There were either no pending requests or no tokens. */ @@ -611,7 +734,6 @@ static struct request *kyber_dispatch_request(struct blk_mq_hw_ctx *hctx) { struct kyber_queue_data *kqd = hctx->queue->elevator->elevator_data; struct kyber_hctx_data *khd = hctx->sched_data; - bool flushed = false; struct request *rq; int i; @@ -622,7 +744,7 @@ static struct request *kyber_dispatch_request(struct blk_mq_hw_ctx *hctx) * from the batch. */ if (khd->batching < kyber_batch_size[khd->cur_domain]) { - rq = kyber_dispatch_cur_domain(kqd, khd, hctx, &flushed); + rq = kyber_dispatch_cur_domain(kqd, khd, hctx); if (rq) goto out; } @@ -643,7 +765,7 @@ static struct request *kyber_dispatch_request(struct blk_mq_hw_ctx *hctx) else khd->cur_domain++; - rq = kyber_dispatch_cur_domain(kqd, khd, hctx, &flushed); + rq = kyber_dispatch_cur_domain(kqd, khd, hctx); if (rq) goto out; } @@ -660,10 +782,12 @@ static bool kyber_has_work(struct blk_mq_hw_ctx *hctx) int i; for (i = 0; i < KYBER_NUM_DOMAINS; i++) { - if (!list_empty_careful(&khd->rqs[i])) + if (!list_empty_careful(&khd->rqs[i]) || + sbitmap_any_bit_set(&khd->kcq_map[i])) return true; } - return sbitmap_any_bit_set(&hctx->ctx_map); + + return false; } #define KYBER_LAT_SHOW_STORE(op) \ @@ -834,7 +958,9 @@ static struct elevator_type kyber_sched = { .init_hctx = kyber_init_hctx, .exit_hctx = kyber_exit_hctx, .limit_depth = kyber_limit_depth, + .bio_merge = kyber_bio_merge, .prepare_request = kyber_prepare_request, + .insert_requests = kyber_insert_requests, .finish_request = kyber_finish_request, .requeue_request = kyber_finish_request, .completed_request = kyber_completed_request, |