Commit fad907cf authored by Ming Lei's avatar Ming Lei Committed by Jens Axboe
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block: move .bd_inode into 1st cacheline of block_device 



The .bd_inode field of block_device is used in IO fast path of
blkdev_write_iter() and blkdev_llseek(), so it is more efficient to keep
it into the 1st cacheline.

.bd_openers is only touched in open()/close(), and .bd_size_lock is only
for updating bdev capacity, which is in slow path too.

So swap .bd_inode layout with .bd_openers & .bd_size_lock to move
.bd_inode into the 1st cache line.

Cc: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
Signed-off-by: default avatarYu Kuai <yukuai3@huawei.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20231128123027.971610-2-yukuai1@huaweicloud.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent bb6cc253

include/linux/blk_types.h

+2 −1
Original line number Diff line number Diff line
@@ -49,9 +49,10 @@ struct block_device { 
	bool			bd_write_holder;

	bool			bd_has_submit_bio;

	dev_t			bd_dev;

	struct inode		*bd_inode;	/* will die */



	atomic_t		bd_openers;

	spinlock_t		bd_size_lock; /* for bd_inode->i_size updates */

	struct inode *		bd_inode;	/* will die */

	void *			bd_claiming;

	void *			bd_holder;

	const struct blk_holder_ops *bd_holder_ops;