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authorMing Lei <ming.lei@redhat.com>2020-06-30 12:25:00 +0200
committerJens Axboe <axboe@kernel.dk>2020-06-30 15:51:48 +0200
commit1fd40b5ea72cf830cfb932bbf791533931c615e9 (patch)
tree2761c53ceccc77cce9905edb698204dac746fa4f /block/blk-mq.c
parentblk-mq: remove dead check from blk_mq_dispatch_rq_list (diff)
downloadlinux-1fd40b5ea72cf830cfb932bbf791533931c615e9.tar.xz
linux-1fd40b5ea72cf830cfb932bbf791533931c615e9.zip
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 <ming.lei@redhat.com> Tested-by: Baolin Wang <baolin.wang7@gmail.com> Reviewed-by: Christoph Hellwig <hch@infradead.org> Cc: Sagi Grimberg <sagi@grimberg.me> Cc: Baolin Wang <baolin.wang7@gmail.com> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-mq.c')
-rw-r--r--block/blk-mq.c31
1 files changed, 27 insertions, 4 deletions
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