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block: re-arrange the struct block_device fields for better layout

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This moves struct device out-of-line as it's just used at open/close
time, so we can keep some of the commonly used fields closer together.
On a standard setup, it also reduces the size from 864 bytes to 848
bytes. Yes, struct device is a pig...

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe 2023-04-14 07:30:16 -06:00
parent 310e9c85c6
commit 3838c406a5
1 changed files with 13 additions and 9 deletions
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22
include/linux/blk_types.h
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@ -40,26 +40,25 @@ struct bio_crypt_ctx;
struct block_device {
sector_t bd_start_sect;
sector_t bd_nr_sectors;
struct gendisk * bd_disk;
struct request_queue * bd_queue;
struct disk_stats __percpu *bd_stats;
unsigned long bd_stamp;
bool bd_read_only; /* read-only policy */
u8 bd_partno;
bool bd_write_holder;
dev_t bd_dev;
atomic_t bd_openers;
spinlock_t bd_size_lock; /* for bd_inode->i_size updates */
struct inode * bd_inode; /* will die */
struct super_block * bd_super;
void * bd_claiming;
struct device bd_device;
void * bd_holder;
int bd_holders;
bool bd_write_holder;
struct kobject *bd_holder_dir;
u8 bd_partno;
spinlock_t bd_size_lock; /* for bd_inode->i_size updates */
struct gendisk * bd_disk;
struct request_queue * bd_queue;
/* The counter of freeze processes */
int bd_fsfreeze_count;
int bd_holders;
struct kobject *bd_holder_dir;
/* Mutex for freeze */
struct mutex bd_fsfreeze_mutex;
struct super_block *bd_fsfreeze_sb;
@ -68,6 +67,11 @@ struct block_device {
#ifdef CONFIG_FAIL_MAKE_REQUEST
bool bd_make_it_fail;
#endif
/*
* keep this out-of-line as it's both big and not needed in the fast
* path
*/
struct device bd_device;
} __randomize_layout;
#define bdev_whole(_bdev) \