io_uring: optimise submission loop invariant

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Instead of keeping @submitted in io_submit_sqes(), which for each
iteration requires comparison with the initial number of SQEs, store the
number of SQEs left to submit. We'll need nr only for when we're done
with SQE handling.

note: if we can't allocate a req for the first SQE we always has been
returning -EAGAIN to the userspace, save this behaviour by looking into
the cache in a slow path.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/c3b3df9aeae4c2f7a53fd8386385742e4e261e77.1649771823.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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Pavel Begunkov 2022-04-12 15:09:49 +01:00 • committed by Jens Axboe

parent fa05457a60

commit 8e6971a819

1 changed files with 15 additions and 17 deletions

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fs/io_uring.c

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