Commit 444d6824 authored Oct 03, 2024 by Pierre-Louis Bossart Committed by Vinod Koul Oct 03, 2024

soundwire: optimize sdw_stream_runtime memory layout



pahole suggestion: swap position of 'm_rt_count'

before: pahole -C sdw_stream_runtime drivers/soundwire/soundwire-bus.ko
struct sdw_stream_runtime {
	const char  *              name;                 /*     0     8 */
	struct sdw_stream_params   params;               /*     8    12 */
	enum sdw_stream_state      state;                /*    20     4 */
	enum sdw_stream_type       type;                 /*    24     4 */

	/* XXX 4 bytes hole, try to pack */

	struct list_head           master_list;          /*    32    16 */
	int                        m_rt_count;           /*    48     4 */

	/* size: 56, cachelines: 1, members: 6 */
	/* sum members: 48, holes: 1, sum holes: 4 */
	/* padding: 4 */
	/* last cacheline: 56 bytes */
};

after: pahole --reorganize -C sdw_stream_runtime drivers/soundwire/soundwire-bus.ko
struct sdw_stream_runtime {
	const char  *              name;                 /*     0     8 */
	struct sdw_stream_params   params;               /*     8    12 */
	enum sdw_stream_state      state;                /*    20     4 */
	enum sdw_stream_type       type;                 /*    24     4 */
	int                        m_rt_count;           /*    28     4 */
	struct list_head           master_list;          /*    32    16 */

	/* size: 48, cachelines: 1, members: 6 */
	/* last cacheline: 48 bytes */
};   /* saved 8 bytes! */

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20241003070650.62787-3-yung-chuan.liao@linux.intel.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>

parent 093227bc

include/linux/soundwire/sdw.h

+5 −5

Original line number	Diff line number	Diff line
		@@ -820,15 +820,15 @@ struct sdw_master_port_ops {
		struct sdw_msg;

		/**
		* struct sdw_defer - SDW deffered message
		* @length: message length
		* struct sdw_defer - SDW deferred message
		* @complete: message completion
		* @msg: SDW message
		* @length: message length
		*/
		struct sdw_defer {
		struct sdw_msg *msg;
		int length;
		struct completion complete;
		struct sdw_msg *msg;
		};

		/**
		@@ -1010,18 +1010,18 @@ struct sdw_stream_params {
		* @params: Stream parameters
		* @state: Current state of the stream
		* @type: Stream type PCM or PDM
		* @m_rt_count: Count of Master runtime(s) in this stream
		* @master_list: List of Master runtime(s) in this stream.
		* master_list can contain only one m_rt per Master instance
		* for a stream
		* @m_rt_count: Count of Master runtime(s) in this stream
		*/
		struct sdw_stream_runtime {
		const char *name;
		struct sdw_stream_params params;
		enum sdw_stream_state state;
		enum sdw_stream_type type;
		struct list_head master_list;
		int m_rt_count;
		struct list_head master_list;
		};

		struct sdw_stream_runtime sdw_alloc_stream(const char stream_name);