[PATCH] io_uring: save repeated issue_flags

[Keith Busch <kbusch@meta.com>]

From: Keith Busch <kbusch@kernel.org>

No need to rebuild the issue_flags on every IO: they're always the same.

Suggested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Keith Busch <kbusch@kernel.org>
---
 include/linux/io_uring_types.h |  1 +
 io_uring/io_uring.c            | 15 ++++++++++++---
 io_uring/uring_cmd.c           |  8 +-------
 3 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
index bebab36abce89..dd192d828f463 100644
--- a/include/linux/io_uring_types.h
+++ b/include/linux/io_uring_types.h
@@ -228,6 +228,7 @@ struct io_ring_ctx {
 	/* const or read-mostly hot data */
 	struct {
 		unsigned int		flags;
+		unsigned int		issue_flags;
 		unsigned int		drain_next: 1;
 		unsigned int		restricted: 1;
 		unsigned int		off_timeout_used: 1;
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 1d254f2c997de..a338e3660ecb8 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -3975,11 +3975,20 @@ static __cold int io_uring_create(unsigned entries, struct io_uring_params *p,
 	 * polling again, they can rely on io_sq_thread to do polling
 	 * work, which can reduce cpu usage and uring_lock contention.
 	 */
-	if (ctx->flags & IORING_SETUP_IOPOLL &&
-	    !(ctx->flags & IORING_SETUP_SQPOLL))
-		ctx->syscall_iopoll = 1;
+	if (ctx->flags & IORING_SETUP_IOPOLL) {
+		ctx->issue_flags |= IO_URING_F_SQE128;
+		if (!(ctx->flags & IORING_SETUP_SQPOLL))
+			ctx->syscall_iopoll = 1;
+	}
 
 	ctx->compat = in_compat_syscall();
+	if (ctx->compat)
+		ctx->issue_flags |= IO_URING_F_COMPAT;
+	if (ctx->flags & IORING_SETUP_SQE128)
+		ctx->issue_flags |= IO_URING_F_SQE128;
+	if (ctx->flags & IORING_SETUP_CQE32)
+		ctx->issue_flags |= IO_URING_F_CQE32;
+
 	if (!ns_capable_noaudit(&init_user_ns, CAP_IPC_LOCK))
 		ctx->user = get_uid(current_user());
 
diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c
index 8a38b9f75d841..dbc0bfbfd0f05 100644
--- a/io_uring/uring_cmd.c
+++ b/io_uring/uring_cmd.c
@@ -158,19 +158,13 @@ int io_uring_cmd(struct io_kiocb *req, unsigned int issue_flags)
 	if (ret)
 		return ret;
 
-	if (ctx->flags & IORING_SETUP_SQE128)
-		issue_flags |= IO_URING_F_SQE128;
-	if (ctx->flags & IORING_SETUP_CQE32)
-		issue_flags |= IO_URING_F_CQE32;
-	if (ctx->compat)
-		issue_flags |= IO_URING_F_COMPAT;
 	if (ctx->flags & IORING_SETUP_IOPOLL) {
 		if (!file->f_op->uring_cmd_iopoll)
 			return -EOPNOTSUPP;
-		issue_flags |= IO_URING_F_IOPOLL;
 		req->iopoll_completed = 0;
 	}
 
+	issue_flags |= ctx->issue_flags;
 	ret = file->f_op->uring_cmd(ioucmd, issue_flags);
 	if (ret == -EAGAIN) {
 		if (!req_has_async_data(req)) {
-- 
2.34.1