diff mbox series

[10/16] block: optimise blkdev_bio_end_io()

Message ID 8e6003932f65ecd9ada5d6296c6eb9d1b946a1eb.1634676157.git.asml.silence@gmail.com (mailing list archive)
State New, archived
Headers show
Series block optimisation round | expand

Commit Message

Pavel Begunkov Oct. 19, 2021, 9:24 p.m. UTC
Save dio->flags in a variable, so it doesn't reload it a bunch of times.
Also use cached in a var iocb for the same reason.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 block/fops.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

Comments

Christoph Hellwig Oct. 20, 2021, 6:30 a.m. UTC | #1
On Tue, Oct 19, 2021 at 10:24:19PM +0100, Pavel Begunkov wrote:
> Save dio->flags in a variable, so it doesn't reload it a bunch of times.
> Also use cached in a var iocb for the same reason.

Same question again, does this really make a difference?  We really
shouldn't have to try to work around the compiler like this (even if
this relatively harmless in the end).
Pavel Begunkov Oct. 20, 2021, 12:29 p.m. UTC | #2
On 10/20/21 07:30, Christoph Hellwig wrote:
> On Tue, Oct 19, 2021 at 10:24:19PM +0100, Pavel Begunkov wrote:
>> Save dio->flags in a variable, so it doesn't reload it a bunch of times.
>> Also use cached in a var iocb for the same reason.
> 
> Same question again, does this really make a difference?  We really

No, will remove the patch

> shouldn't have to try to work around the compiler like this (even if
> this relatively harmless in the end).
diff mbox series

Patch

diff --git a/block/fops.c b/block/fops.c
index 8f733c919ed1..8e3790faafb8 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -145,13 +145,13 @@  static struct bio_set blkdev_dio_pool;
 static void blkdev_bio_end_io(struct bio *bio)
 {
 	struct blkdev_dio *dio = bio->bi_private;
-	bool should_dirty = dio->flags & DIO_SHOULD_DIRTY;
+	unsigned int flags = dio->flags;
 
 	if (bio->bi_status && !dio->bio.bi_status)
 		dio->bio.bi_status = bio->bi_status;
 
-	if (!(dio->flags & DIO_MULTI_BIO) || atomic_dec_and_test(&dio->ref)) {
-		if (!(dio->flags & DIO_IS_SYNC)) {
+	if (!(flags & DIO_MULTI_BIO) || atomic_dec_and_test(&dio->ref)) {
+		if (!(flags & DIO_IS_SYNC)) {
 			struct kiocb *iocb = dio->iocb;
 			ssize_t ret;
 
@@ -164,8 +164,8 @@  static void blkdev_bio_end_io(struct bio *bio)
 				ret = blk_status_to_errno(dio->bio.bi_status);
 			}
 
-			dio->iocb->ki_complete(iocb, ret, 0);
-			if (dio->flags & DIO_MULTI_BIO)
+			iocb->ki_complete(iocb, ret, 0);
+			if (flags & DIO_MULTI_BIO)
 				bio_put(&dio->bio);
 		} else {
 			struct task_struct *waiter = dio->waiter;
@@ -175,7 +175,7 @@  static void blkdev_bio_end_io(struct bio *bio)
 		}
 	}
 
-	if (should_dirty) {
+	if (flags & DIO_SHOULD_DIRTY) {
 		bio_check_pages_dirty(bio);
 	} else {
 		bio_release_pages(bio, false);