archive mirror
 help / color / mirror / Atom feed
From: Lin Feng <>
Subject: [RFC PATCH 2/2] bfq/mq-deadline: remove redundant check for passthrough request
Date: Thu, 15 Apr 2021 11:43:26 +0800	[thread overview]
Message-ID: <> (raw)

Since commit 01e99aeca39796003 'blk-mq: insert passthrough request into
hctx->dispatch directly', passthrough request should not appear in
IO-scheduler any more, so blk_rq_is_passthrough checking in addon IO
schedulers is redundant.

(Notes: this patch passes generic IO load test with hdds under SAS
controller and hdds under AHCI controller but obviously not covers all.
Not sure if passthrough request can still escape into IO scheduler from
blk_mq_sched_insert_requests, which is used by blk_mq_flush_plug_list and
has lots of indirect callers.)

Signed-off-by: Lin Feng <>
 block/bfq-iosched.c | 2 +-
 block/mq-deadline.c | 7 ++-----
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 95586137194e..b827c9212b02 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -5627,7 +5627,7 @@ static void bfq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
 	bfqq = bfq_init_rq(rq);
-	if (!bfqq || at_head || blk_rq_is_passthrough(rq)) {
+	if (!bfqq || at_head) {
 		if (at_head)
 			list_add(&rq->queuelist, &bfqd->dispatch);
diff --git a/block/mq-deadline.c b/block/mq-deadline.c
index f3631a287466..04aded71ead2 100644
--- a/block/mq-deadline.c
+++ b/block/mq-deadline.c
@@ -500,11 +500,8 @@ static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
-	if (at_head || blk_rq_is_passthrough(rq)) {
-		if (at_head)
-			list_add(&rq->queuelist, &dd->dispatch);
-		else
-			list_add_tail(&rq->queuelist, &dd->dispatch);
+	if (at_head) {
+		list_add(&rq->queuelist, &dd->dispatch);
 	} else {
 		deadline_add_rq_rb(dd, rq);

             reply	other threads:[~2021-04-15  3:56 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-15  3:43 Lin Feng [this message]
2021-04-16  2:14 ` [RFC PATCH 2/2] bfq/mq-deadline: remove redundant check for passthrough request Ming Lei
2021-04-16 12:09 ` Jens Axboe

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \ \ \ \ \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).