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authorDavid Rientjes <rientjes@google.com>2014-06-04 16:08:25 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-06-04 16:54:06 -0700
commit68711a746345c44ae00c64d8dbac6a9ce13ac54a (patch)
treed6a3df9bf1894362bcae1ecefb7c43598e009d99 /include/linux/migrate.h
parent93f39eea9c229778361ae7ecf5f5e95d291757da (diff)
downloadlinux-68711a746345c44ae00c64d8dbac6a9ce13ac54a.tar.gz
linux-68711a746345c44ae00c64d8dbac6a9ce13ac54a.tar.xz
mm, migration: add destination page freeing callback
Memory migration uses a callback defined by the caller to determine how to allocate destination pages. When migration fails for a source page, however, it frees the destination page back to the system. This patch adds a memory migration callback defined by the caller to determine how to free destination pages. If a caller, such as memory compaction, builds its own freelist for migration targets, this can reuse already freed memory instead of scanning additional memory. If the caller provides a function to handle freeing of destination pages, it is called when page migration fails. If the caller passes NULL then freeing back to the system will be handled as usual. This patch introduces no functional change. Signed-off-by: David Rientjes <rientjes@google.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Greg Thelen <gthelen@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/migrate.h')
-rw-r--r--include/linux/migrate.h11
1 files changed, 7 insertions, 4 deletions
diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index 84a31ad0b791..a2901c414664 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -5,7 +5,9 @@
#include <linux/mempolicy.h>
#include <linux/migrate_mode.h>
-typedef struct page *new_page_t(struct page *, unsigned long private, int **);
+typedef struct page *new_page_t(struct page *page, unsigned long private,
+ int **reason);
+typedef void free_page_t(struct page *page, unsigned long private);
/*
* Return values from addresss_space_operations.migratepage():
@@ -38,7 +40,7 @@ enum migrate_reason {
extern void putback_movable_pages(struct list_head *l);
extern int migrate_page(struct address_space *,
struct page *, struct page *, enum migrate_mode);
-extern int migrate_pages(struct list_head *l, new_page_t x,
+extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free,
unsigned long private, enum migrate_mode mode, int reason);
extern int migrate_prep(void);
@@ -56,8 +58,9 @@ extern int migrate_page_move_mapping(struct address_space *mapping,
#else
static inline void putback_movable_pages(struct list_head *l) {}
-static inline int migrate_pages(struct list_head *l, new_page_t x,
- unsigned long private, enum migrate_mode mode, int reason)
+static inline int migrate_pages(struct list_head *l, new_page_t new,
+ free_page_t free, unsigned long private, enum migrate_mode mode,
+ int reason)
{ return -ENOSYS; }
static inline int migrate_prep(void) { return -ENOSYS; }