io_uring: optimise io_import_iovec nonblock passing

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First, change IO_URING_F_NONBLOCK to take sign bit of the int, so
checking for it can be turned into test + sign-based-jump, makes the
binary smaller and may be faster.

Then, instead of passing need_lock boolean into io_import_iovec() just
give it issue_flags, which is already stored somewhere. Saves some space
on stack, a couple of test + cmov operations and other conversions.

note: we still leave
force_nonblock = issue_flags & IO_URING_F_NONBLOCK
variable, but it's optimised out by the compiler into testing
issue_flags directly.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/ee96547e692f6c975c229cd82fc721679571a734.1634144845.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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This commit is contained in:

Pavel Begunkov 2021-10-14 16:10:17 +01:00 • committed by Jens Axboe

parent c88598a92a

commit 51aac424ae

1 changed files with 25 additions and 22 deletions

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fs/io_uring.c

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