[PATCH 5.13 244/351] io_uring: shuffle rarely used ctx fields

Greg Kroah-Hartman
2021-07-19T17:51:08Z

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

[ Upstream commit b986af7e2df4f0871367c397ba61a542f37c0ab3 ]

There is a bunch of scattered around ctx fields that are almost never
used, e.g. only on ring exit, plunge them to the end, better locality,
better aesthetically.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/782ff94b00355923eae757d58b1a47821b5b46d4.1621201931.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/io_uring.c | 36 +++++++++++++++++-------------------
1 file changed, 17 insertions(+), 19 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 2bf2aacb4c81..5d685c92b8fd 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -369,9 +369,6 @@ struct io_ring_ctx {
unsigned cached_cq_overflow;
unsigned long sq_check_overflow;

- /* hashed buffered write serialization */
- struct io_wq_hash *hash_map;
-
struct list_head defer_list;
struct list_head timeout_list;
struct list_head cq_overflow_list;
@@ -388,9 +385,6 @@ struct io_ring_ctx {

struct io_rings *rings;

- /* Only used for accounting purposes */
- struct mm_struct *mm_account;
-
const struct cred *sq_creds; /* cred used for __io_sq_thread() */
struct io_sq_data *sq_data; /* if using sq thread polling */

@@ -411,14 +405,6 @@ struct io_ring_ctx {
unsigned nr_user_bufs;
struct io_mapped_ubuf **user_bufs;

- struct user_struct *user;
-
- struct completion ref_comp;
-
-#if defined(CONFIG_UNIX)
- struct socket *ring_sock;
-#endif
-
struct xarray io_buffers;

struct xarray personalities;
@@ -462,12 +448,24 @@ struct io_ring_ctx {

struct io_restriction restrictions;

- /* exit task_work */
- struct callback_head *exit_task_work;
-
/* Keep this last, we don't need it for the fast path */
- struct work_struct exit_work;
- struct list_head tctx_list;
+ struct {
+ #if defined(CONFIG_UNIX)
+ struct socket *ring_sock;
+ #endif
+ /* hashed buffered write serialization */
+ struct io_wq_hash *hash_map;
+
+ /* Only used for accounting purposes */
+ struct user_struct *user;
+ struct mm_struct *mm_account;
+
+ /* ctx exit and cancelation */
+ struct callback_head *exit_task_work;
+ struct work_struct exit_work;
+ struct list_head tctx_list;
+ struct completion ref_comp;
+ };
};

struct io_uring_task {
--
2.30.2