From d88cbbb39b4db057feb1552de31f22c02a21b36f Mon Sep 17 00:00:00 2001 From: Christophe JAILLET Date: Fri, 17 Feb 2023 10:29:10 +0100 Subject: [PATCH] blk-mq: Reorder fields in 'struct blk_mq_tag_set' Group some variables based on their sizes to reduce hole and avoid padding. On x86_64, this shrinks the size of 'struct blk_mq_tag_set' from 304 to 296 bytes. Signed-off-by: Christophe JAILLET Link: https://lore.kernel.org/r/6f249f9b02a3490283ef0278096556de41aa0cf0.1676626130.git.christophe.jaillet@wanadoo.fr Signed-off-by: Jens Axboe --- include/linux/blk-mq.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 779fba6..dd5ce11 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -473,6 +473,7 @@ enum hctx_type { /** * struct blk_mq_tag_set - tag set that can be shared between request queues + * @ops: Pointers to functions that implement block driver behavior. * @map: One or more ctx -> hctx mappings. One map exists for each * hardware queue type (enum hctx_type) that the driver wishes * to support. There are no restrictions on maps being of the @@ -480,7 +481,6 @@ enum hctx_type { * types. * @nr_maps: Number of elements in the @map array. A number in the range * [1, HCTX_MAX_TYPES]. - * @ops: Pointers to functions that implement block driver behavior. * @nr_hw_queues: Number of hardware queues supported by the block driver that * owns this data structure. * @queue_depth: Number of tags per hardware queue, reserved tags included. @@ -505,9 +505,9 @@ enum hctx_type { * (BLK_MQ_F_BLOCKING). */ struct blk_mq_tag_set { + const struct blk_mq_ops *ops; struct blk_mq_queue_map map[HCTX_MAX_TYPES]; unsigned int nr_maps; - const struct blk_mq_ops *ops; unsigned int nr_hw_queues; unsigned int queue_depth; unsigned int reserved_tags; -- 2.7.4