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From: Christoph Hellwig <hch@lst.de>
To: Jens Axboe <axboe@kernel.dk>
Cc: Jeffle Xu <jefflexu@linux.alibaba.com>,
	Ming Lei <ming.lei@redhat.com>,
	Damien Le Moal <Damien.LeMoal@wdc.com>,
	Keith Busch <kbusch@kernel.org>, Sagi Grimberg <sagi@grimberg.me>,
	"Wunderlich, Mark" <mark.wunderlich@intel.com>,
	"Vasudevan, Anil" <anil.vasudevan@intel.com>,
	linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-nvme@lists.infradead.org
Subject: [PATCH 02/16] block: don't try to poll multi-bio I/Os in __blkdev_direct_IO
Date: Tue, 15 Jun 2021 15:10:20 +0200	[thread overview]
Message-ID: <20210615131034.752623-3-hch@lst.de> (raw)
In-Reply-To: <20210615131034.752623-1-hch@lst.de>

If an iocb is split into multiple bios we can't poll for both.  So don't
bother to even try to poll in that case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/block_dev.c | 21 +++++++--------------
 1 file changed, 7 insertions(+), 14 deletions(-)

diff --git a/fs/block_dev.c b/fs/block_dev.c
index ac9b3c158a77..8600c651b0b0 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -375,7 +375,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 	struct blk_plug plug;
 	struct blkdev_dio *dio;
 	struct bio *bio;
-	bool is_poll = (iocb->ki_flags & IOCB_HIPRI) != 0;
+	bool do_poll = (iocb->ki_flags & IOCB_HIPRI);
 	bool is_read = (iov_iter_rw(iter) == READ), is_sync;
 	loff_t pos = iocb->ki_pos;
 	blk_qc_t qc = BLK_QC_T_NONE;
@@ -404,7 +404,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 	 * Don't plug for HIPRI/polled IO, as those should go straight
 	 * to issue
 	 */
-	if (!is_poll)
+	if (!(iocb->ki_flags & IOCB_HIPRI))
 		blk_start_plug(&plug);
 
 	for (;;) {
@@ -438,20 +438,13 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 
 		nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS);
 		if (!nr_pages) {
-			bool polled = false;
-
-			if (iocb->ki_flags & IOCB_HIPRI) {
+			if (do_poll)
 				bio_set_polled(bio, iocb);
-				polled = true;
-			}
-
 			qc = submit_bio(bio);
-
-			if (polled)
+			if (do_poll)
 				WRITE_ONCE(iocb->ki_cookie, qc);
 			break;
 		}
-
 		if (!dio->multi_bio) {
 			/*
 			 * AIO needs an extra reference to ensure the dio
@@ -462,6 +455,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 				bio_get(bio);
 			dio->multi_bio = true;
 			atomic_set(&dio->ref, 2);
+			do_poll = false;
 		} else {
 			atomic_inc(&dio->ref);
 		}
@@ -470,7 +464,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 		bio = bio_alloc(GFP_KERNEL, nr_pages);
 	}
 
-	if (!is_poll)
+	if (!(iocb->ki_flags & IOCB_HIPRI))
 		blk_finish_plug(&plug);
 
 	if (!is_sync)
@@ -481,8 +475,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 		if (!READ_ONCE(dio->waiter))
 			break;
 
-		if (!(iocb->ki_flags & IOCB_HIPRI) ||
-		    !blk_poll(bdev_get_queue(bdev), qc, true))
+		if (!do_poll || !blk_poll(bdev_get_queue(bdev), qc, true))
 			blk_io_schedule();
 	}
 	__set_current_state(TASK_RUNNING);
-- 
2.30.2


WARNING: multiple messages have this Message-ID
From: Christoph Hellwig <hch@lst.de>
To: Jens Axboe <axboe@kernel.dk>
Cc: Jeffle Xu <jefflexu@linux.alibaba.com>,
	Ming Lei <ming.lei@redhat.com>,
	Damien Le Moal <Damien.LeMoal@wdc.com>,
	Keith Busch <kbusch@kernel.org>, Sagi Grimberg <sagi@grimberg.me>,
	"Wunderlich, Mark" <mark.wunderlich@intel.com>,
	"Vasudevan, Anil" <anil.vasudevan@intel.com>,
	linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-nvme@lists.infradead.org
Subject: [PATCH 02/16] block: don't try to poll multi-bio I/Os in __blkdev_direct_IO
Date: Tue, 15 Jun 2021 15:10:20 +0200	[thread overview]
Message-ID: <20210615131034.752623-3-hch@lst.de> (raw)
In-Reply-To: <20210615131034.752623-1-hch@lst.de>

If an iocb is split into multiple bios we can't poll for both.  So don't
bother to even try to poll in that case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/block_dev.c | 21 +++++++--------------
 1 file changed, 7 insertions(+), 14 deletions(-)

diff --git a/fs/block_dev.c b/fs/block_dev.c
index ac9b3c158a77..8600c651b0b0 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -375,7 +375,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 	struct blk_plug plug;
 	struct blkdev_dio *dio;
 	struct bio *bio;
-	bool is_poll = (iocb->ki_flags & IOCB_HIPRI) != 0;
+	bool do_poll = (iocb->ki_flags & IOCB_HIPRI);
 	bool is_read = (iov_iter_rw(iter) == READ), is_sync;
 	loff_t pos = iocb->ki_pos;
 	blk_qc_t qc = BLK_QC_T_NONE;
@@ -404,7 +404,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 	 * Don't plug for HIPRI/polled IO, as those should go straight
 	 * to issue
 	 */
-	if (!is_poll)
+	if (!(iocb->ki_flags & IOCB_HIPRI))
 		blk_start_plug(&plug);
 
 	for (;;) {
@@ -438,20 +438,13 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 
 		nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS);
 		if (!nr_pages) {
-			bool polled = false;
-
-			if (iocb->ki_flags & IOCB_HIPRI) {
+			if (do_poll)
 				bio_set_polled(bio, iocb);
-				polled = true;
-			}
-
 			qc = submit_bio(bio);
-
-			if (polled)
+			if (do_poll)
 				WRITE_ONCE(iocb->ki_cookie, qc);
 			break;
 		}
-
 		if (!dio->multi_bio) {
 			/*
 			 * AIO needs an extra reference to ensure the dio
@@ -462,6 +455,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 				bio_get(bio);
 			dio->multi_bio = true;
 			atomic_set(&dio->ref, 2);
+			do_poll = false;
 		} else {
 			atomic_inc(&dio->ref);
 		}
@@ -470,7 +464,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 		bio = bio_alloc(GFP_KERNEL, nr_pages);
 	}
 
-	if (!is_poll)
+	if (!(iocb->ki_flags & IOCB_HIPRI))
 		blk_finish_plug(&plug);
 
 	if (!is_sync)
@@ -481,8 +475,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 		if (!READ_ONCE(dio->waiter))
 			break;
 
-		if (!(iocb->ki_flags & IOCB_HIPRI) ||
-		    !blk_poll(bdev_get_queue(bdev), qc, true))
+		if (!do_poll || !blk_poll(bdev_get_queue(bdev), qc, true))
 			blk_io_schedule();
 	}
 	__set_current_state(TASK_RUNNING);
-- 
2.30.2


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  parent reply	other threads:[~2021-06-15 13:11 UTC|newest]

Thread overview: 48+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-15 13:10 switch block layer polling to a bio based model v4 Christoph Hellwig
2021-06-15 13:10 ` [PATCH 01/16] direct-io: remove blk_poll support Christoph Hellwig
2021-06-15 13:10 ` Christoph Hellwig [this message]
2021-06-15 13:10 ` [PATCH 03/16] iomap: don't try to poll multi-bio I/Os in __iomap_dio_rw Christoph Hellwig
2021-06-15 13:10 ` [PATCH 04/16] blk-mq: factor out a blk_qc_to_hctx helper Christoph Hellwig
2021-06-15 13:10 ` [PATCH 05/16] blk-mq: factor out a "classic" poll helper Christoph Hellwig
2021-06-15 13:10 ` [PATCH 06/16] blk-mq: remove blk_qc_t_to_tag and blk_qc_t_is_internal Christoph Hellwig
2021-06-15 13:10 ` [PATCH 07/16] blk-mq: remove blk_qc_t_valid Christoph Hellwig
2021-06-15 13:10 ` [PATCH 08/16] block: replace the spin argument to blk_iopoll with a flags argument Christoph Hellwig
2021-06-15 13:10 ` [PATCH 09/16] io_uring: don't sleep when polling for I/O Christoph Hellwig
2021-06-15 13:10 ` [PATCH 10/16] block: rename REQ_HIPRI to REQ_POLLED Christoph Hellwig
2021-06-15 13:10 ` [PATCH 11/16] block: use SLAB_TYPESAFE_BY_RCU for the bio slab Christoph Hellwig
2021-06-15 13:10 ` [PATCH 12/16] block: define 'struct bvec_iter' as packed Christoph Hellwig
2021-06-15 13:10 ` [PATCH 13/16] block: switch polling to be bio based Christoph Hellwig
2021-06-16  2:30   ` Ming Lei
2021-06-18 14:01     ` Christoph Hellwig
2021-06-18 14:27       ` Ming Lei
2021-06-21  7:20         ` Christoph Hellwig
2021-06-21  8:35           ` Ming Lei
2021-06-15 13:10 ` [PATCH 14/16] block: don't allow writing to the poll queue attribute Christoph Hellwig
2021-06-15 13:10 ` [PATCH 15/16] nvme-multipath: set QUEUE_FLAG_NOWAIT Christoph Hellwig
2021-06-15 13:10 ` [PATCH 16/16] nvme-multipath: enable polled I/O Christoph Hellwig
2021-06-15 14:37 ` switch block layer polling to a bio based model v4 Keith Busch
2021-06-15 16:06   ` Christoph Hellwig

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