Commit 407728da authored by Christophe JAILLET's avatar Christophe JAILLET Committed by Jens Axboe
Browse files

block, bfq: Reorder struct bfq_iocq_bfqq_data 



The size of struct bfq_iocq_bfqq_data can be reduced by moving a few
fields around.

On a x86_64, with allmodconfig, this shrinks the size from 144 to 128
bytes. The main benefit is to reduce the size of struct bfq_io_cq from
1360 to 1232.

This structure is stored in a dedicated slab cache. So reducing its size
improves cache usage.

Signed-off-by: default avatarChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: default avatarYu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/79394db1befaa658e8066b8e3348073ce27d9d26.1754119538.git.christophe.jaillet@wanadoo.fr


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 984ff00c

block/bfq-iosched.h

+5 −5
Original line number Diff line number Diff line
@@ -427,9 +427,6 @@ struct bfq_iocq_bfqq_data { 
	 */

	bool saved_IO_bound;



	u64 saved_io_start_time;

	u64 saved_tot_idle_time;



	/*

	 * Same purpose as the previous fields for the values of the

	 * field keeping the queue's belonging to a large burst
@@ -450,6 +447,9 @@ struct bfq_iocq_bfqq_data { 
	 */

	unsigned int saved_weight;



	u64 saved_io_start_time;

	u64 saved_tot_idle_time;



	/*

	 * Similar to previous fields: save wr information.

	 */
@@ -457,13 +457,13 @@ struct bfq_iocq_bfqq_data { 
	unsigned long saved_last_wr_start_finish;

	unsigned long saved_service_from_wr;

	unsigned long saved_wr_start_at_switch_to_srt;

	unsigned int saved_wr_cur_max_time;

	struct bfq_ttime saved_ttime;

	unsigned int saved_wr_cur_max_time;



	/* Save also injection state */

	u64 saved_last_serv_time_ns;

	unsigned int saved_inject_limit;

	unsigned long saved_decrease_time_jif;

	u64 saved_last_serv_time_ns;



	/* candidate queue for a stable merge (due to close creation time) */

	struct bfq_queue *stable_merge_bfqq;