From: Jens Axboe <axboe@kernel.dk>
To: io-uring@vger.kernel.org
Subject: [PATCHSET 0/2] Multishot read tweaks
Date: Mon, 1 Apr 2024 11:49:14 -0600 [thread overview]
Message-ID: <20240401175306.1051122-1-axboe@kernel.dk> (raw)
Hi,
We can't properly support multishot reads unless one of the following
conditions are true:
1) The file supports proper FMODE_NOWAIT
2) Barring proper FMODE_NOWAIT support, the file must be opened in
non-blocking O_NONBLOCK mode
Without either one of those, non-blocking retries cannot be attempted.
And without that, it's pointless to support multishot reads.
If this is attempted, fall back to singleshot mode. This will properly
do the initial CQE posting, but will not set IORING_CQE_F_MORE as we
can't reliably perform the retries that multishot requires.
io_uring/io_uring.c | 13 +++++++++----
io_uring/rw.c | 9 ++++++++-
2 files changed, 17 insertions(+), 5 deletions(-)
--
Jens Axboe
next reply other threads:[~2024-04-01 17:53 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-01 17:49 Jens Axboe [this message]
2024-04-01 17:49 ` [PATCH 1/2] io_uring/rw: don't allow multishot reads without NOWAIT support Jens Axboe
2024-04-01 17:49 ` [PATCH 2/2] io_uring: disable io-wq execution of multishot NOWAIT requests Jens Axboe
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