Frontswap: swap data structure changes
Subsystems (2)
PATCH v3 1/4 Frontswap: swap data structure changes
[PATCH V3 1/4] Frontswap: swap data structure changes
Core swap data structures are needed by frontswap.c but we don't need to expose them to the dozens of files that include swap.h so create a new swapfile.h just to extern-ify these.
Add frontswap-related elements to swap_info_struct. Don't tie these to CONFIG_FRONTSWAP to avoid unnecessary clutter around various frontswap hooks.
Signed-off-by Dan Magenheimer <[email protected]>
Diffstat:
swap.h | 2 ++ swapfile.h | 13 +++++++++++++ 2 files changed, 15 insertions(+)
include/linux/swapfile.h +13 -0
@@ -0,0 +1,13 @@ +#ifndef _LINUX_SWAPFILE_H +#define _LINUX_SWAPFILE_H + +/* +* these were static in swapfile.c but frontswap.c needs them and we don't +* want to expose them to the dozens of source files that include swap.h +*/ +extern spinlock_t swap_lock; +extern struct swap_list_t swap_list; +extern struct swap_info_struct *swap_info[]; +extern int try_to_unuse (unsigned int ,bool ,unsigned long ); + +#endif /* _LINUX_SWAPFILE_H */
include/linux/swap.h +2 -0
@@ -185,6 +185,8 @@ struct swap_info_struct {struct block_device *bdev;/* swap device or bdev of swap file */ struct file *swap_file;/* seldom referenced */ unsigned int old_block_size;/* seldom referenced */ +unsigned long *frontswap_map;/* frontswap in-use, one bit per page */ +unsigned int frontswap_pages;/* frontswap pages in-use counter */ };struct swap_list_t {
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