From 1fd40b5ea72cf830cfb932bbf791533931c615e9 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Tue, 30 Jun 2020 18:25:00 +0800 Subject: blk-mq: pass obtained budget count to blk_mq_dispatch_rq_list Pass obtained budget count to blk_mq_dispatch_rq_list(), and prepare for supporting fully batching submission. With the obtained budget count, it is easier to put extra budgets in case of .queue_rq failure. Meantime remove the old 'got_budget' parameter. Signed-off-by: Ming Lei Tested-by: Baolin Wang Reviewed-by: Christoph Hellwig Cc: Sagi Grimberg Cc: Baolin Wang Cc: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-mq.c | 31 +++++++++++++++++++++++++++---- 1 file changed, 27 insertions(+), 4 deletions(-) (limited to 'block/blk-mq.c') diff --git a/block/blk-mq.c b/block/blk-mq.c index a80cb6ecc9d9..1b701e166681 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1280,7 +1280,12 @@ static enum prep_dispatch blk_mq_prep_dispatch_rq(struct request *rq, * we'll re-run it below. */ if (!blk_mq_mark_tag_wait(hctx, rq)) { - blk_mq_put_dispatch_budget(rq->q); + /* + * All budgets not got from this function will be put + * together during handling partial dispatch + */ + if (need_budget) + blk_mq_put_dispatch_budget(rq->q); return PREP_DISPATCH_NO_TAG; } } @@ -1288,11 +1293,21 @@ static enum prep_dispatch blk_mq_prep_dispatch_rq(struct request *rq, return PREP_DISPATCH_OK; } +/* release all allocated budgets before calling to blk_mq_dispatch_rq_list */ +static void blk_mq_release_budgets(struct request_queue *q, + unsigned int nr_budgets) +{ + int i; + + for (i = 0; i < nr_budgets; i++) + blk_mq_put_dispatch_budget(q); +} + /* * Returns true if we did some work AND can potentially do more. */ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list, - bool got_budget) + unsigned int nr_budgets) { enum prep_dispatch prep; struct request_queue *q = hctx->queue; @@ -1304,7 +1319,7 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list, if (list_empty(list)) return false; - WARN_ON(!list_is_singular(list) && got_budget); + WARN_ON(!list_is_singular(list) && nr_budgets); /* * Now process all the entries, sending them to the driver. @@ -1316,7 +1331,7 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list, rq = list_first_entry(list, struct request, queuelist); WARN_ON_ONCE(hctx != rq->mq_hctx); - prep = blk_mq_prep_dispatch_rq(rq, !got_budget); + prep = blk_mq_prep_dispatch_rq(rq, !nr_budgets); if (prep != PREP_DISPATCH_OK) break; @@ -1335,6 +1350,12 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list, bd.last = !blk_mq_get_driver_tag(nxt); } + /* + * once the request is queued to lld, no need to cover the + * budget any more + */ + if (nr_budgets) + nr_budgets--; ret = q->mq_ops->queue_rq(hctx, &bd); if (ret == BLK_STS_RESOURCE || ret == BLK_STS_DEV_RESOURCE) { blk_mq_handle_dev_resource(rq, list); @@ -1376,6 +1397,8 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list, (hctx->flags & BLK_MQ_F_TAG_SHARED); bool no_budget_avail = prep == PREP_DISPATCH_NO_BUDGET; + blk_mq_release_budgets(q, nr_budgets); + /* * If we didn't flush the entire list, we could have told * the driver there was more coming, but that turned out to -- cgit v1.2.3