io_uring: move 'poll_multi_queue' bool in io_ring_ctx

The cacheline section holding this variable has two gaps, where one is
caused by this bool not packing well with structs. This causes it to
blow into the next cacheline. Move the variable, shrinking io_ring_ctx
by a full cacheline in size.

Signed-off-by: Jens Axboe <[email protected]>

Author: axboe

include/linux/io_uring_types.h

@@ -292,6 +292,8 @@ struct io_ring_ctx {
 	struct {
 		spinlock_t		completion_lock;
 
+		bool			poll_multi_queue;
+
 		/*
 		 * ->iopoll_list is protected by the ctx->uring_lock for
 		 * io_uring instances that don't use IORING_SETUP_SQPOLL.
@@ -300,7 +302,6 @@ struct io_ring_ctx {
 		 */
 		struct io_wq_work_list	iopoll_list;
 		struct io_hash_table	cancel_table;
-		bool			poll_multi_queue;
 
 		struct llist_head	work_llist;