io_uring: remove drain_active check from hot path

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req->ctx->active_drain is a bit too expensive, partially because of two
dereferences. Do a trick, if we see it set in io_init_req(), set
REQ_F_FORCE_ASYNC and it automatically goes through a slower path where
we can catch it. It's nearly free to do in io_init_req() because there
is already ->restricted check and it's in the same byte of a bitmask.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d7e7ddc63c15e8a300833132abb3eb8fd3918aef.1632516769.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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Pavel Begunkov 2021-09-24 21:59:57 +01:00 • committed by Jens Axboe

parent f15a343177

commit 2a56a9bd64

1 changed files with 29 additions and 24 deletions

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fs/io_uring.c

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