[PATCH 03/12] io_uring: shuffle more fields into SQ ctx section

Pavel Begunkov
2021-06-14T22:39:08Z

Since moving locked_free_* out of struct io_submit_state
ctx->submit_state is accessed on submission side only, so move it into
the submission section. Same goes for rsrc table pointers/nodes/etc.,
they must be taken and checked during submission because sync'ed by
uring_lock, so move them there as well.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
fs/io_uring.c | 35 +++++++++++++++++------------------
1 file changed, 17 insertions(+), 18 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index a4460383bd25..5cc0c4dd2709 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -353,6 +353,7 @@ struct io_ring_ctx {
unsigned int restricted: 1;
} ____cacheline_aligned_in_smp;

+ /* submission data */
struct {
/*
* Ring buffer of indices into array of io_uring_sqe, which is
@@ -369,13 +370,27 @@ struct io_ring_ctx {
struct io_uring_sqe *sq_sqes;
unsigned cached_sq_head;
unsigned sq_entries;
- unsigned sq_thread_idle;
unsigned cached_sq_dropped;
unsigned long sq_check_overflow;
-
struct list_head defer_list;
+
+ /*
+ * Fixed resources fast path, should be accessed only under
+ * uring_lock, and updated through io_uring_register(2)
+ */
+ struct io_rsrc_node *rsrc_node;
+ struct io_file_table file_table;
+ unsigned nr_user_files;
+ unsigned nr_user_bufs;
+ struct io_mapped_ubuf **user_bufs;
+
+ struct io_submit_state submit_state;
struct list_head timeout_list;
struct list_head cq_overflow_list;
+ struct xarray io_buffers;
+ struct xarray personalities;
+ u32 pers_next;
+ unsigned sq_thread_idle;
} ____cacheline_aligned_in_smp;

struct {
@@ -383,7 +398,6 @@ struct io_ring_ctx {
wait_queue_head_t wait;
} ____cacheline_aligned_in_smp;

- struct io_submit_state submit_state;
/* IRQ completion list, under ->completion_lock */
struct list_head locked_free_list;
unsigned int locked_free_nr;
@@ -394,21 +408,6 @@ struct io_ring_ctx {
struct wait_queue_head sqo_sq_wait;
struct list_head sqd_list;

- /*
- * Fixed resources fast path, should be accessed only under uring_lock,
- * and updated through io_uring_register(2)
- */
- struct io_rsrc_node *rsrc_node;
-
- struct io_file_table file_table;
- unsigned nr_user_files;
- unsigned nr_user_bufs;
- struct io_mapped_ubuf **user_bufs;
-
- struct xarray io_buffers;
- struct xarray personalities;
- u32 pers_next;
-
struct {
unsigned cached_cq_tail;
unsigned cq_entries;
--
2.31.1