From 62c4f0a2d5a188f73a94f2cb8ea0dba3e7cf0a7f Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Wed, 26 Apr 2006 12:56:16 +0100 Subject: Don't include linux/config.h from anywhere else in include/ Signed-off-by: David Woodhouse --- include/linux/swap.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/linux/swap.h') diff --git a/include/linux/swap.h b/include/linux/swap.h index 5b1fdf1cff4f..e24fa9b69cbf 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -1,7 +1,6 @@ #ifndef _LINUX_SWAP_H #define _LINUX_SWAP_H -#include #include #include #include -- cgit v1.2.3 From e8f03d02080b25f53cd6bba8dc3a297803f18c01 Mon Sep 17 00:00:00 2001 From: Andreas Dilger Date: Fri, 23 Jun 2006 02:03:14 -0700 Subject: [PATCH] reserve space for swap label Reserve space in the swap disk header for a LABEL and UUID to be specified. This has been possible with util-linux-2.12b (via e2fsprogs 1.36 libblkid), and is used by at least FC3 and later. The kernel doesn't really care about this, but the space shouldn't accidentally be used by something else either. Also make the on-disk structures be fixed-size types, instead of "int", though I don't know of any architecture in use where an "int" isn't the same size as a "__u32" (all current kernel arches have it as "unsigned int"). Signed-off-by: Andreas Dilger Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/swap.h | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) (limited to 'include/linux/swap.h') diff --git a/include/linux/swap.h b/include/linux/swap.h index aca9bfae208f..cd28ad206dae 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -48,12 +48,14 @@ union swap_header { char magic[10]; /* SWAP-SPACE or SWAPSPACE2 */ } magic; struct { - char bootbits[1024]; /* Space for disklabel etc. */ - unsigned int version; - unsigned int last_page; - unsigned int nr_badpages; - unsigned int padding[125]; - unsigned int badpages[1]; + char bootbits[1024]; /* Space for disklabel etc. */ + __u32 version; + __u32 last_page; + __u32 nr_badpages; + unsigned char sws_uuid[16]; + unsigned char sws_volume[16]; + __u32 padding[117]; + __u32 badpages[1]; } info; }; -- cgit v1.2.3 From 0697212a411c1dae03c27845f2de2f3adb32c331 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Fri, 23 Jun 2006 02:03:35 -0700 Subject: [PATCH] Swapless page migration: add R/W migration entries Implement read/write migration ptes We take the upper two swapfiles for the two types of migration ptes and define a series of macros in swapops.h. The VM is modified to handle the migration entries. migration entries can only be encountered when the page they are pointing to is locked. This limits the number of places one has to fix. We also check in copy_pte_range and in mprotect_pte_range() for migration ptes. We check for migration ptes in do_swap_cache and call a function that will then wait on the page lock. This allows us to effectively stop all accesses to apge. Migration entries are created by try_to_unmap if called for migration and removed by local functions in migrate.c From: Hugh Dickins Several times while testing swapless page migration (I've no NUMA, just hacking it up to migrate recklessly while running load), I've hit the BUG_ON(!PageLocked(p)) in migration_entry_to_page. This comes from an orphaned migration entry, unrelated to the current correctly locked migration, but hit by remove_anon_migration_ptes as it checks an address in each vma of the anon_vma list. Such an orphan may be left behind if an earlier migration raced with fork: copy_one_pte can duplicate a migration entry from parent to child, after remove_anon_migration_ptes has checked the child vma, but before it has removed it from the parent vma. (If the process were later to fault on this orphaned entry, it would hit the same BUG from migration_entry_wait.) This could be fixed by locking anon_vma in copy_one_pte, but we'd rather not. There's no such problem with file pages, because vma_prio_tree_add adds child vma after parent vma, and the page table locking at each end is enough to serialize. Follow that example with anon_vma: add new vmas to the tail instead of the head. (There's no corresponding problem when inserting migration entries, because a missed pte will leave the page count and mapcount high, which is allowed for. And there's no corresponding problem when migrating via swap, because a leftover swap entry will be correctly faulted. But the swapless method has no refcounting of its entries.) From: Ingo Molnar pte_unmap_unlock() takes the pte pointer as an argument. From: Hugh Dickins Several times while testing swapless page migration, gcc has tried to exec a pointer instead of a string: smells like COW mappings are not being properly write-protected on fork. The protection in copy_one_pte looks very convincing, until at last you realize that the second arg to make_migration_entry is a boolean "write", and SWP_MIGRATION_READ is 30. Anyway, it's better done like in change_pte_range, using is_write_migration_entry and make_migration_entry_read. From: Hugh Dickins Remove unnecessary obfuscation from sys_swapon's range check on swap type, which blew up causing memory corruption once swapless migration made MAX_SWAPFILES no longer 2 ^ MAX_SWAPFILES_SHIFT. Signed-off-by: Hugh Dickins Acked-by: Martin Schwidefsky Signed-off-by: Hugh Dickins Signed-off-by: Christoph Lameter Signed-off-by: Ingo Molnar From: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/swap.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/linux/swap.h') diff --git a/include/linux/swap.h b/include/linux/swap.h index cd28ad206dae..7cee73ef4f15 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -28,7 +28,14 @@ static inline int current_is_kswapd(void) * the type/offset into the pte as 5/27 as well. */ #define MAX_SWAPFILES_SHIFT 5 +#ifndef CONFIG_MIGRATION #define MAX_SWAPFILES (1 << MAX_SWAPFILES_SHIFT) +#else +/* Use last two entries for page migration swap entries */ +#define MAX_SWAPFILES ((1 << MAX_SWAPFILES_SHIFT)-2) +#define SWP_MIGRATION_READ MAX_SWAPFILES +#define SWP_MIGRATION_WRITE (MAX_SWAPFILES + 1) +#endif /* * Magic header for a swap area. The first part of the union is -- cgit v1.2.3 From 04e62a29bf157ce1edd168f2b71b533c80d13628 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Fri, 23 Jun 2006 02:03:38 -0700 Subject: [PATCH] More page migration: use migration entries for file pages This implements the use of migration entries to preserve ptes of file backed pages during migration. Processes can therefore be migrated back and forth without loosing their connection to pagecache pages. Note that we implement the migration entries only for linear mappings. Nonlinear mappings still require the unmapping of the ptes for migration. And another writepage() ugliness shows up. writepage() can drop the page lock. Therefore we have to remove migration ptes before calling writepages() in order to avoid having migration entries point to unlocked pages. Signed-off-by: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/swap.h | 15 --------------- 1 file changed, 15 deletions(-) (limited to 'include/linux/swap.h') diff --git a/include/linux/swap.h b/include/linux/swap.h index 7cee73ef4f15..1cf234e8df55 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -186,20 +186,6 @@ extern unsigned long shrink_all_memory(unsigned long nr_pages); extern int vm_swappiness; extern int remove_mapping(struct address_space *mapping, struct page *page); -/* possible outcome of pageout() */ -typedef enum { - /* failed to write page out, page is locked */ - PAGE_KEEP, - /* move page to the active list, page is locked */ - PAGE_ACTIVATE, - /* page has been sent to the disk successfully, page is unlocked */ - PAGE_SUCCESS, - /* page is clean and locked */ - PAGE_CLEAN, -} pageout_t; - -extern pageout_t pageout(struct page *page, struct address_space *mapping); - #ifdef CONFIG_NUMA extern int zone_reclaim_mode; extern int zone_reclaim_interval; @@ -259,7 +245,6 @@ extern int remove_exclusive_swap_page(struct page *); struct backing_dev_info; extern spinlock_t swap_lock; -extern int remove_vma_swap(struct vm_area_struct *vma, struct page *page); /* linux/mm/thrash.c */ extern struct mm_struct * swap_token_mm; -- cgit v1.2.3 From bd96b9eb7cfd6ab24ba244360a09980a720874d2 Mon Sep 17 00:00:00 2001 From: Con Kolivas Date: Fri, 23 Jun 2006 02:03:42 -0700 Subject: [PATCH] mm: fix swap unused warning MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If CONFIG_SWAP is not defined we get: mm/vmscan.c: In function ‘remove_mapping’: mm/vmscan.c:387: warning: unused variable ‘swap’ Convert defines in swap.h into blank inline functions to fix this warning and be consistent. Signed-off-by: Con Kolivas Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/swap.h | 64 +++++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 53 insertions(+), 11 deletions(-) (limited to 'include/linux/swap.h') diff --git a/include/linux/swap.h b/include/linux/swap.h index 1cf234e8df55..f1a827a972e0 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -282,18 +282,60 @@ static inline void disable_swap_token(void) #define free_pages_and_swap_cache(pages, nr) \ release_pages((pages), (nr), 0); -#define show_swap_cache_info() /*NOTHING*/ -#define free_swap_and_cache(swp) /*NOTHING*/ -#define swap_duplicate(swp) /*NOTHING*/ -#define swap_free(swp) /*NOTHING*/ -#define read_swap_cache_async(swp,vma,addr) NULL -#define lookup_swap_cache(swp) NULL -#define valid_swaphandles(swp, off) 0 +static inline void show_swap_cache_info(void) +{ +} + +static inline void free_swap_and_cache(swp_entry_t swp) +{ +} + +static inline int swap_duplicate(swp_entry_t swp) +{ + return 0; +} + +static inline void swap_free(swp_entry_t swp) +{ +} + +static inline struct page *read_swap_cache_async(swp_entry_t swp, + struct vm_area_struct *vma, unsigned long addr) +{ + return NULL; +} + +static inline struct page *lookup_swap_cache(swp_entry_t swp) +{ + return NULL; +} + +static inline int valid_swaphandles(swp_entry_t entry, unsigned long *offset) +{ + return 0; +} + #define can_share_swap_page(p) (page_mapcount(p) == 1) -#define move_to_swap_cache(p, swp) 1 -#define move_from_swap_cache(p, i, m) 1 -#define __delete_from_swap_cache(p) /*NOTHING*/ -#define delete_from_swap_cache(p) /*NOTHING*/ + +static inline int move_to_swap_cache(struct page *page, swp_entry_t entry) +{ + return 1; +} + +static inline int move_from_swap_cache(struct page *page, unsigned long index, + struct address_space *mapping) +{ + return 1; +} + +static inline void __delete_from_swap_cache(struct page *page) +{ +} + +static inline void delete_from_swap_cache(struct page *page) +{ +} + #define swap_token_default_timeout 0 static inline int remove_exclusive_swap_page(struct page *p) -- cgit v1.2.3 From bd1e22b8e0a90f9a91e4c27db14ca15773659bf7 Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Fri, 23 Jun 2006 02:03:47 -0700 Subject: [PATCH] initialise total_memory() earlier Initialise total_memory earlier in boot. Because if for some reason we run page reclaim early in boot, we don't want total_memory to be zero when we use it as a divisor. And rename total_memory to vm_total_pages to avoid naming clashes with architectures. Cc: Yasunori Goto Cc: KAMEZAWA Hiroyuki Cc: Martin Bligh Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/swap.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/swap.h') diff --git a/include/linux/swap.h b/include/linux/swap.h index f1a827a972e0..dc3f3aa0c83e 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -185,6 +185,7 @@ extern unsigned long try_to_free_pages(struct zone **, gfp_t); extern unsigned long shrink_all_memory(unsigned long nr_pages); extern int vm_swappiness; extern int remove_mapping(struct address_space *mapping, struct page *page); +extern long vm_total_pages; #ifdef CONFIG_NUMA extern int zone_reclaim_mode; -- cgit v1.2.3