From e126391c092014af7ea6786648c9f1d3fce512a3 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Tue, 12 Apr 2022 15:09:45 +0100 Subject: [PATCH] io_uring: shrink final link flush All good users should not set IOSQE_IO_*LINK flags for the last request of a link. io_uring flushes collected links at the end of submission, but it's not the optimal way and so we don't care too much about it. Replace io_queue_sqe() call with io_queue_sqe_fallback() as the former one is inlined and will generate a bunch of extra code. This will also help compilers with the submission path inlining. > size ./fs/io_uring.o text data bss dec hex filename 87265 13734 8 101007 18a8f ./fs/io_uring.o > size ./fs/io_uring.o text data bss dec hex filename 87073 13734 8 100815 189cf ./fs/io_uring.o Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/01fb5e417ef49925d544a0b0bae30409845ed2b4.1649771823.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- fs/io_uring.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 188923c38bfc..a3a3c80e2faa 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -7785,8 +7785,8 @@ static void io_submit_state_end(struct io_ring_ctx *ctx) { struct io_submit_state *state = &ctx->submit_state; - if (state->link.head) - io_queue_sqe(state->link.head); + if (unlikely(state->link.head)) + io_queue_sqe_fallback(state->link.head); /* flush only after queuing links as they can generate completions */ io_submit_flush_completions(ctx); if (state->plug_started)