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authorLinus Torvalds <torvalds@linux-foundation.org>2012-12-11 18:05:37 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-12-11 18:05:37 -0800
commit608ff1a210ab0e8b969399039bf8e18693605910 (patch)
treefaea7bb1764461c73d0953089bd5439d91733a03 /include/linux/migrate.h
parent414a6750e59b0b687034764c464e9ddecac0f7a6 (diff)
parent74d42d8fe146e870c52bde3b1c692f86cc8ff844 (diff)
downloadop-kernel-dev-608ff1a210ab0e8b969399039bf8e18693605910.zip
op-kernel-dev-608ff1a210ab0e8b969399039bf8e18693605910.tar.gz
Merge branch 'akpm' (Andrew's patchbomb)
Merge misc updates from Andrew Morton: "About half of most of MM. Going very early this time due to uncertainty over the coreautounifiednumasched things. I'll send the other half of most of MM tomorrow. The rest of MM awaits a slab merge from Pekka." * emailed patches from Andrew Morton: (71 commits) memory_hotplug: ensure every online node has NORMAL memory memory_hotplug: handle empty zone when online_movable/online_kernel mm, memory-hotplug: dynamic configure movable memory and portion memory drivers/base/node.c: cleanup node_state_attr[] bootmem: fix wrong call parameter for free_bootmem() avr32, kconfig: remove HAVE_ARCH_BOOTMEM mm: cma: remove watermark hacks mm: cma: skip watermarks check for already isolated blocks in split_free_page() mm, oom: fix race when specifying a thread as the oom origin mm, oom: change type of oom_score_adj to short mm: cleanup register_node() mm, mempolicy: remove duplicate code mm/vmscan.c: try_to_freeze() returns boolean mm: introduce putback_movable_pages() virtio_balloon: introduce migration primitives to balloon pages mm: introduce compaction and migration for ballooned pages mm: introduce a common interface for balloon pages mobility mm: redefine address_space.assoc_mapping mm: adjust address_space_operations.migratepage() return code arch/sparc/kernel/sys_sparc_64.c: s/COLOUR/COLOR/ ...
Diffstat (limited to 'include/linux/migrate.h')
-rw-r--r--include/linux/migrate.h19
1 files changed, 19 insertions, 0 deletions
diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index ce7e667..0b5865c6 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -7,9 +7,27 @@
typedef struct page *new_page_t(struct page *, unsigned long private, int **);
+/*
+ * Return values from addresss_space_operations.migratepage():
+ * - negative errno on page migration failure;
+ * - zero on page migration success;
+ *
+ * The balloon page migration introduces this special case where a 'distinct'
+ * return code is used to flag a successful page migration to unmap_and_move().
+ * This approach is necessary because page migration can race against balloon
+ * deflation procedure, and for such case we could introduce a nasty page leak
+ * if a successfully migrated balloon page gets released concurrently with
+ * migration's unmap_and_move() wrap-up steps.
+ */
+#define MIGRATEPAGE_SUCCESS 0
+#define MIGRATEPAGE_BALLOON_SUCCESS 1 /* special ret code for balloon page
+ * sucessful migration case.
+ */
+
#ifdef CONFIG_MIGRATION
extern void putback_lru_pages(struct list_head *l);
+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,
@@ -33,6 +51,7 @@ extern int migrate_huge_page_move_mapping(struct address_space *mapping,
#else
static inline void putback_lru_pages(struct list_head *l) {}
+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, bool offlining,
enum migrate_mode mode) { return -ENOSYS; }
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