From: Ming Lei <ming.lei@redhat.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org, Christoph Hellwig <hch@lst.de>,
Ming Lei <ming.lei@redhat.com>
Subject: [RFC PATCH 8/8] loop: use backing dio at default
Date: Mon, 25 Oct 2021 17:44:37 +0800 [thread overview]
Message-ID: <20211025094437.2837701-9-ming.lei@redhat.com> (raw)
In-Reply-To: <20211025094437.2837701-1-ming.lei@redhat.com>
We have supported to fallback to buffered IO in case dio failure. Also
in reality, most of or quite a lot of IOs(such as FS IO) are actually aligned,
even though loop's logical block size isn't matched with backing
queue's.
So enable direct io at default.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
drivers/block/loop.c | 9 ++-------
1 file changed, 2 insertions(+), 7 deletions(-)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index e42c0e3601ac..df057dca7512 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -2285,13 +2285,8 @@ static int loop_add(int i)
blk_queue_max_hw_sectors(lo->lo_queue, BLK_DEF_MAX_SECTORS);
- /*
- * By default, we do buffer IO, so it doesn't make sense to enable
- * merge because the I/O submitted to backing file is handled page by
- * page. For directio mode, merge does help to dispatch bigger request
- * to underlayer disk. We will enable merge once directio is enabled.
- */
- blk_queue_flag_set(QUEUE_FLAG_NOMERGES, lo->lo_queue);
+ /* use backing dio at default */
+ lo->lo_flags |= LO_FLAGS_DIRECT_IO;
/*
* Disable partition scanning by default. The in-kernel partition
--
2.31.1
prev parent reply other threads:[~2021-10-25 9:47 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-25 9:44 [PATCH 0/8] loop: improve dio on backing file Ming Lei
2021-10-25 9:44 ` [PATCH 1/8] loop: move flush_dcache_page to ->complete of request Ming Lei
2021-10-26 7:21 ` Christoph Hellwig
2021-10-25 9:44 ` [PATCH 2/8] loop: remove always true check Ming Lei
2021-10-26 7:31 ` Christoph Hellwig
2021-10-25 9:44 ` [PATCH 3/8] loop: add one helper for submitting IO on backing file Ming Lei
2021-10-25 9:44 ` [PATCH 4/8] loop: cover simple read/write via lo_rw_aio() Ming Lei
2021-10-26 7:35 ` Christoph Hellwig
2021-10-25 9:44 ` [PATCH 5/8] loop: fallback to buffered IO in case of dio submission Ming Lei
2021-10-26 7:36 ` Christoph Hellwig
2021-10-25 9:44 ` [PATCH 6/8] loop: relax loop dio use condition Ming Lei
2021-10-26 7:37 ` Christoph Hellwig
2021-10-27 0:20 ` kernel test robot
2021-10-25 9:44 ` [PATCH 7/8] loop: remove lo->use_dio Ming Lei
2021-10-25 9:44 ` Ming Lei [this message]
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