Messages in this thread Patch in this message | | | Date | Thu, 22 Apr 2010 06:43:09 -0700 | From | Dan Magenheimer <> | Subject | Frontswap [PATCH 1/4] (was Transcendent Memory): swap data structure changes |
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Frontswap [PATCH 1/4] (was Transcendent Memory): 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 <dan.magenheimer@oracle.com>
Diffstat: swap.h | 2 ++ swapfile.h | 13 +++++++++++++ 2 files changed, 15 insertions(+)
--- linux-2.6.34-rc5/include/linux/swapfile.h 1969-12-31 17:00:00.000000000 -0700 +++ linux-2.6.34-rc5-frontswap/include/linux/swapfile.h 2010-04-21 08:59:36.000000000 -0600 @@ -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 */ --- linux-2.6.34-rc5/include/linux/swap.h 2010-04-19 17:29:56.000000000 -0600 +++ linux-2.6.34-rc5-frontswap/include/linux/swap.h 2010-04-21 08:59:36.000000000 -0600 @@ -182,6 +182,8 @@ 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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