[RFC PATCH v4 02/16] io_uring: delayed cqe commit

[David Wei <dw@davidwei.uk>]

From: Pavel Begunkov <asml.silence@gmail.com>

RFC only, not for upstream

A stub patch allowing to delay and batch the final step of cqe posting
for aux cqes. A different version will be sent separately to upstream.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: David Wei <dw@davidwei.uk>
---
 include/linux/io_uring_types.h | 1 +
 io_uring/io_uring.c            | 3 ++-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
index d8111d64812b..500772189fee 100644
--- a/include/linux/io_uring_types.h
+++ b/include/linux/io_uring_types.h
@@ -205,6 +205,7 @@ struct io_submit_state {
 
 	bool			plug_started;
 	bool			need_plug;
+	bool			flush_cqes;
 	unsigned short		submit_nr;
 	unsigned int		cqes_count;
 	struct blk_plug		plug;
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index cf2f514b7cc0..e44c2ef271b9 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -176,7 +176,7 @@ static struct ctl_table kernel_io_uring_disabled_table[] = {
 static inline void io_submit_flush_completions(struct io_ring_ctx *ctx)
 {
 	if (!wq_list_empty(&ctx->submit_state.compl_reqs) ||
-	    ctx->submit_state.cqes_count)
+	    ctx->submit_state.cqes_count || ctx->submit_state.flush_cqes)
 		__io_submit_flush_completions(ctx);
 }
 
@@ -1598,6 +1598,7 @@ void __io_submit_flush_completions(struct io_ring_ctx *ctx)
 		io_free_batch_list(ctx, state->compl_reqs.first);
 		INIT_WQ_LIST(&state->compl_reqs);
 	}
+	ctx->submit_state.flush_cqes = false;
 }
 
 static unsigned io_cqring_events(struct io_ring_ctx *ctx)
-- 
2.43.0