From: Dan Magenheimer <dan.magenheimer@xxxxxxxxxx> Subject: [PATCH V7 1/4] mm: frontswap: swap data structure changes This first patch of four in the frontswap series makes available core swap data structures (swap_lock, swap_list and swap_info) that are needed by frontswap.c but we don't need to expose them to the dozens of files that include swap.h so we create a new swapfile.h just to extern-ify these. Also add frontswap-related elements to swap_info_struct. Frontswap_map points to vzalloc'ed one-bit-per-swap-page metadata that indicates whether the swap page is in frontswap or in the device and frontswap_pages counts how many pages are in frontswap. [v7: rebase to 3.0-rc3] [v7: JBeulich@xxxxxxxxxx: add new swap struct elements only if config'd] [v6: rebase to 3.0-rc1] [v5: no change from v4] [v4: rebase to 2.6.39] Signed-off-by: Dan Magenheimer <dan.magenheimer@xxxxxxxxxx> Reviewed-by: Konrad Wilk <konrad.wilk@xxxxxxxxxx> Acked-by: Jan Beulich <JBeulich@xxxxxxxxxx> Acked-by: Seth Jennings <sjenning@xxxxxxxxxxxxxxxxxx> Cc: Jeremy Fitzhardinge <jeremy@xxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Nitin Gupta <ngupta@xxxxxxxxxx> Cc: Matthew Wilcox <matthew@xxxxxx> Cc: Chris Mason <chris.mason@xxxxxxxxxx> Cc: Rik Riel <riel@xxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- linux/include/linux/swapfile.h 1969-12-31 17:00:00.000000000 -0700 +++ frontswap/include/linux/swapfile.h 2011-08-23 08:20:09.757818005 -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/include/linux/swap.h 2011-08-08 08:19:25.880690134 -0600 +++ frontswap/include/linux/swap.h 2011-08-23 08:27:57.584694638 -0600 @@ -194,6 +194,10 @@ 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 */ +#ifdef CONFIG_FRONTSWAP + unsigned long *frontswap_map; /* frontswap in-use, one bit per page */ + unsigned int frontswap_pages; /* frontswap pages in-use counter */ +#endif }; struct swap_list_t { -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>