Commit da08d2ed authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring: re-arrange struct io_ring_ctx to reduce padding 



Nothing major here, just moving a few things around to reduce the
padding. This reduces the size on a non-debug kernel from 1536 to
1472 bytes, saving a full cacheline.

Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent af5d68f8

include/linux/io_uring_types.h

+16 −15
Original line number Diff line number Diff line
@@ -240,6 +240,7 @@ struct io_ring_ctx { 
		unsigned int		poll_activated: 1;

		unsigned int		drain_disabled: 1;

		unsigned int		compat: 1;

		unsigned int		iowq_limits_set : 1;



		struct task_struct	*submitter_task;

		struct io_rings		*rings;
@@ -274,10 +275,20 @@ struct io_ring_ctx { 
		 */

		struct io_rsrc_node	*rsrc_node;

		atomic_t		cancel_seq;



		/*

		 * ->iopoll_list is protected by the ctx->uring_lock for

		 * io_uring instances that don't use IORING_SETUP_SQPOLL.

		 * For SQPOLL, only the single threaded io_sq_thread() will

		 * manipulate the list, hence no extra locking is needed there.

		 */

		bool			poll_multi_queue;

		struct io_wq_work_list	iopoll_list;



		struct io_file_table	file_table;

		struct io_mapped_ubuf	**user_bufs;

		unsigned		nr_user_files;

		unsigned		nr_user_bufs;

		struct io_mapped_ubuf	**user_bufs;



		struct io_submit_state	submit_state;
@@ -288,15 +299,6 @@ struct io_ring_ctx { 
		struct io_alloc_cache	apoll_cache;

		struct io_alloc_cache	netmsg_cache;



		/*

		 * ->iopoll_list is protected by the ctx->uring_lock for

		 * io_uring instances that don't use IORING_SETUP_SQPOLL.

		 * For SQPOLL, only the single threaded io_sq_thread() will

		 * manipulate the list, hence no extra locking is needed there.

		 */

		struct io_wq_work_list	iopoll_list;

		bool			poll_multi_queue;



		/*

		 * Any cancelable uring_cmd is added to this list in

		 * ->uring_cmd() by io_uring_cmd_insert_cancelable()
@@ -343,8 +345,8 @@ struct io_ring_ctx { 
	spinlock_t		completion_lock;



	/* IRQ completion list, under ->completion_lock */

	struct io_wq_work_list	locked_free_list;

	unsigned int		locked_free_nr;

	struct io_wq_work_list	locked_free_list;



	struct list_head	io_buffers_comp;

	struct list_head	cq_overflow_list;
@@ -366,9 +368,6 @@ struct io_ring_ctx { 
	unsigned int		file_alloc_start;

	unsigned int		file_alloc_end;



	struct xarray		personalities;

	u32			pers_next;



	struct list_head	io_buffers_cache;



	/* deferred free list, protected by ->uring_lock */
@@ -389,6 +388,9 @@ struct io_ring_ctx { 
	struct wait_queue_head		rsrc_quiesce_wq;

	unsigned			rsrc_quiesce;



	u32			pers_next;

	struct xarray		personalities;



	/* hashed buffered write serialization */

	struct io_wq_hash		*hash_map;
@@ -405,7 +407,6 @@ struct io_ring_ctx { 


	/* io-wq management, e.g. thread count */

	u32				iowq_limits[2];

	bool				iowq_limits_set;



	struct callback_head		poll_wq_task_work;

	struct list_head		defer_list;