io_uring: move uring_lock location

->uring_lock is prevalently used for submission, even though it protects
many other things like iopoll, registeration, selected bufs, and more.
And it's placed together with ->cq_wait poked on completion and CQ
waiting sides. Move them apart, ->uring_lock goes to the submission
data, and cq_wait to completion related chunk. The last one requires
some reshuffling so everything needed by io_cqring_ev_posted*() is in
one cacheline.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/dea5e845caee4c98aa0922b46d713154d81f7bd8.1623709150.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index e19c9f7..74c8334 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -356,6 +356,8 @@ struct io_ring_ctx {
 
        /* submission data */
        struct {
+               struct mutex            uring_lock;
+
                /*
                 * Ring buffer of indices into array of io_uring_sqe, which is
                 * mmapped by the application using the IORING_OFF_SQES offset.
@@ -392,11 +394,6 @@ struct io_ring_ctx {
                unsigned                sq_thread_idle;
        } ____cacheline_aligned_in_smp;
 
-       struct {
-               struct mutex            uring_lock;
-               wait_queue_head_t       cq_wait;
-       } ____cacheline_aligned_in_smp;
-
        /* IRQ completion list, under ->completion_lock */
        struct list_head        locked_free_list;
        unsigned int            locked_free_nr;
@@ -412,12 +409,13 @@ struct io_ring_ctx {
        struct {
                unsigned                cached_cq_tail;
                unsigned                cq_entries;
-               atomic_t                cq_timeouts;
-               unsigned                cq_last_tm_flush;
-               unsigned                cq_extra;
+               struct eventfd_ctx      *cq_ev_fd;
                struct wait_queue_head  poll_wait;
+               struct wait_queue_head  cq_wait;
+               unsigned                cq_extra;
+               atomic_t                cq_timeouts;
                struct fasync_struct    *cq_fasync;
-               struct eventfd_ctx      *cq_ev_fd;
+               unsigned                cq_last_tm_flush;
        } ____cacheline_aligned_in_smp;
 
        struct {