[PATCH 5/8] io_uring: don't reinit submit state every time

[Pavel Begunkov <asml.silence@gmail.com>]

As now submit_state is retained across syscalls, we can save ourself
from initialising it from ground up for each io_submit_sqes(). Set some
fields during ctx allocation, and just keep them always consistent.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 fs/io_uring.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 7d811cf0c27b..08d0c8b60c2a 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1284,6 +1284,7 @@ static inline bool io_is_timeout_noseq(struct io_kiocb *req)
 
 static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
 {
+	struct io_submit_state *submit_state;
 	struct io_ring_ctx *ctx;
 	int hash_bits;
 
@@ -1335,6 +1336,12 @@ static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
 	INIT_LIST_HEAD(&ctx->rsrc_ref_list);
 	INIT_DELAYED_WORK(&ctx->rsrc_put_work, io_rsrc_put_work);
 	init_llist_head(&ctx->rsrc_put_llist);
+
+	submit_state = &ctx->submit_state;
+	INIT_LIST_HEAD(&submit_state->comp.list);
+	submit_state->comp.nr = 0;
+	submit_state->file_refs = 0;
+	submit_state->free_reqs = 0;
 	return ctx;
 err:
 	if (ctx->fallback_req)
@@ -6703,8 +6710,10 @@ static void io_submit_state_end(struct io_submit_state *state,
 	if (state->plug_started)
 		blk_finish_plug(&state->plug);
 	io_state_file_put(state);
-	if (state->free_reqs)
+	if (state->free_reqs) {
 		kmem_cache_free_bulk(req_cachep, state->free_reqs, state->reqs);
+		state->free_reqs = 0;
+	}
 }
 
 /*
@@ -6714,10 +6723,6 @@ static void io_submit_state_start(struct io_submit_state *state,
 				  unsigned int max_ios)
 {
 	state->plug_started = false;
-	state->comp.nr = 0;
-	INIT_LIST_HEAD(&state->comp.list);
-	state->free_reqs = 0;
-	state->file_refs = 0;
 	state->ios_left = max_ios;
 }
 
-- 
2.24.0