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, 12 Oct 2021 13:12:12 +0200 [thread overview]
Message-ID: <20211012111226.760968-3-hch@lst.de> (raw)
In-Reply-To: <20211012111226.760968-1-hch@lst.de>
If an iocb is split into multiple bios we can't poll for both. So don't
even bother to try to poll in that case.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
block/fops.c | 21 +++++++--------------
1 file changed, 7 insertions(+), 14 deletions(-)
diff --git a/block/fops.c b/block/fops.c
index 7bb9581a146cf..15324f2e5a914 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -197,7 +197,7 @@ 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;
@@ -226,7 +226,7 @@ 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 (;;) {
@@ -260,20 +260,13 @@ 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
@@ -284,6 +277,7 @@ 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);
}
@@ -292,7 +286,7 @@ 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)
@@ -303,8 +297,7 @@ 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
next prev parent reply other threads:[~2021-10-12 11:17 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-12 11:12 switch block layer polling to a bio based model v4 Christoph Hellwig
2021-10-12 11:12 ` [PATCH 01/16] direct-io: remove blk_poll support Christoph Hellwig
2021-10-13 10:42 ` Sagi Grimberg
2021-10-28 1:26 ` Chaitanya Kulkarni
2021-10-12 11:12 ` Christoph Hellwig [this message]
2021-10-12 11:12 ` [PATCH 03/16] iomap: don't try to poll multi-bio I/Os in __iomap_dio_rw Christoph Hellwig
2021-10-12 11:12 ` [PATCH 04/16] io_uring: fix a layering violation in io_iopoll_req_issued Christoph Hellwig
2021-10-12 11:12 ` [PATCH 05/16] blk-mq: factor out a blk_qc_to_hctx helper Christoph Hellwig
2021-10-12 11:12 ` [PATCH 06/16] blk-mq: factor out a "classic" poll helper Christoph Hellwig
2021-10-12 11:12 ` [PATCH 07/16] blk-mq: remove blk_qc_t_to_tag and blk_qc_t_is_internal Christoph Hellwig
2021-10-12 11:12 ` [PATCH 08/16] blk-mq: remove blk_qc_t_valid Christoph Hellwig
2021-10-12 11:12 ` [PATCH 09/16] block: replace the spin argument to blk_iopoll with a flags argument Christoph Hellwig
2021-10-13 10:44 ` Sagi Grimberg
2021-10-12 11:12 ` [PATCH 10/16] io_uring: don't sleep when polling for I/O Christoph Hellwig
2021-10-13 10:45 ` Sagi Grimberg
2021-10-12 11:12 ` [PATCH 11/16] block: rename REQ_HIPRI to REQ_POLLED Christoph Hellwig
2021-10-13 10:45 ` Sagi Grimberg
2021-10-12 11:12 ` [PATCH 12/16] block: use SLAB_TYPESAFE_BY_RCU for the bio slab Christoph Hellwig
2021-10-12 11:12 ` [PATCH 13/16] block: define 'struct bvec_iter' as packed Christoph Hellwig
2021-10-12 11:12 ` [PATCH 14/16] block: switch polling to be bio based Christoph Hellwig
2021-10-13 9:59 ` Ming Lei
2021-10-13 10:45 ` Sagi Grimberg
2021-10-15 8:30 ` Pankaj Raghav
2021-10-15 13:24 ` Christoph Hellwig
2021-11-03 7:11 ` chenxiang (M)
2021-11-03 7:22 ` Christoph Hellwig
2021-11-03 8:05 ` chenxiang (M)
2021-10-12 11:12 ` [PATCH 15/16] block: don't allow writing to the poll queue attribute Christoph Hellwig
2021-10-12 11:12 ` [PATCH 16/16] nvme-multipath: enable polled I/O Christoph Hellwig
2021-10-13 10:46 ` Sagi Grimberg
2021-10-12 14:47 ` switch block layer polling to a bio based model v4 Jens Axboe
2021-10-12 14:57 ` Sagi Grimberg
2021-10-12 14:58 ` Jens Axboe
2021-10-12 15:09 ` Sagi Grimberg
2021-10-12 15:06 ` Christoph Hellwig
-- strict thread matches above, loose matches on Subject: below --
2021-06-15 13:10 Christoph Hellwig
2021-06-15 13:10 ` [PATCH 02/16] block: don't try to poll multi-bio I/Os in __blkdev_direct_IO Christoph Hellwig
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