Linux block layer
 help / color / mirror / Atom feed
From: Bart Van Assche <bart.vanassche@sandisk.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org,
	"Bart Van Assche" <bart.vanassche@sandisk.com>,
	"Christoph Hellwig" <hch@lst.de>,
	"Matias Bjørling" <m@bjorling.me>
Subject: [PATCH 5/5] block: Optimize ioprio_best()
Date: Tue, 18 Apr 2017 16:10:37 -0700	[thread overview]
Message-ID: <20170418231037.3968-6-bart.vanassche@sandisk.com> (raw)
In-Reply-To: <20170418231037.3968-1-bart.vanassche@sandisk.com>

Since ioprio_best() translates IOPRIO_CLASS_NONE into IOPRIO_CLASS_BE
and since lower numerical priority values represent a higher priority
a simple numerical comparison is sufficient.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Adam Manzanares <adam.manzanares@wdc.com>
Tested-by: Adam Manzanares <adam.manzanares@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Matias Bjørling <m@bjorling.me>
---
 block/ioprio.c | 12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

diff --git a/block/ioprio.c b/block/ioprio.c
index 0c47a00f92a8..4b120c9cf7e8 100644
--- a/block/ioprio.c
+++ b/block/ioprio.c
@@ -163,22 +163,12 @@ static int get_task_ioprio(struct task_struct *p)
 
 int ioprio_best(unsigned short aprio, unsigned short bprio)
 {
-	unsigned short aclass;
-	unsigned short bclass;
-
 	if (!ioprio_valid(aprio))
 		aprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, IOPRIO_NORM);
 	if (!ioprio_valid(bprio))
 		bprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, IOPRIO_NORM);
 
-	aclass = IOPRIO_PRIO_CLASS(aprio);
-	bclass = IOPRIO_PRIO_CLASS(bprio);
-	if (aclass == bclass)
-		return min(aprio, bprio);
-	if (aclass > bclass)
-		return bprio;
-	else
-		return aprio;
+	return min(aprio, bprio);
 }
 
 SYSCALL_DEFINE2(ioprio_get, int, which, int, who)
-- 
2.12.2

  parent reply	other threads:[~2017-04-18 23:10 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-18 23:10 [PATCH 0/5] Reduce code duplication Bart Van Assche
2017-04-18 23:10 ` [PATCH 1/5] block: Export blk_init_request_from_bio() Bart Van Assche
2017-04-19  6:16   ` Christoph Hellwig
2017-04-18 23:10 ` [PATCH 2/5] null_blk: Use blk_init_request_from_bio() instead of open-coding it Bart Van Assche
2017-04-19  6:18   ` Christoph Hellwig
2017-04-18 23:10 ` [PATCH 3/5] lightnvm: " Bart Van Assche
2017-04-19  6:19   ` Christoph Hellwig
2017-04-18 23:10 ` [PATCH 4/5] block: Inline blk_rq_set_prio() Bart Van Assche
2017-04-19  6:20   ` Christoph Hellwig
2017-04-19 14:38     ` Jens Axboe
2017-04-19 15:54       ` Bart Van Assche
2017-04-18 23:10 ` Bart Van Assche [this message]
2017-04-19  6:21   ` [PATCH 5/5] block: Optimize ioprio_best() Christoph Hellwig

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:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

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

  git send-email \
    --in-reply-to=20170418231037.3968-6-bart.vanassche@sandisk.com \
    --to=bart.vanassche@sandisk.com \
    --cc=axboe@kernel.dk \
    --cc=hch@lst.de \
    --cc=linux-block@vger.kernel.org \
    --cc=m@bjorling.me \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* 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