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authorChristoph Lameter <clameter@sgi.com>2006-06-25 05:46:48 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-06-25 10:00:55 -0700
commit7b2259b3e53f128c10a9fded0965e69d4a949847 (patch)
treec1827144c22dd49775190e05de791531e9fd21fd
parent68402ddc677005ed1b1359bbc1f279548cfc0928 (diff)
[PATCH] page migration: Support a vma migration function
Hooks for calling vma specific migration functions With this patch a vma may define a vma->vm_ops->migrate function. That function may perform page migration on its own (some vmas may not contain page structs and therefore cannot be handled by regular page migration. Pages in a vma may require special preparatory treatment before migration is possible etc) . Only mmap_sem is held when the migration function is called. The migrate() function gets passed two sets of nodemasks describing the source and the target of the migration. The flags parameter either contains MPOL_MF_MOVE which means that only pages used exclusively by the specified mm should be moved or MPOL_MF_MOVE_ALL which means that pages shared with other processes should also be moved. The migration function returns 0 on success or an error condition. An error condition will prevent regular page migration from occurring. On its own this patch cannot be included since there are no users for this functionality. But it seems that the uncached allocator will need this functionality at some point. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--include/linux/migrate.h11
-rw-r--r--include/linux/mm.h2
-rw-r--r--mm/mempolicy.c6
-rw-r--r--mm/migrate.c20
4 files changed, 37 insertions, 2 deletions
diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index 5dba23a1c0d..48148e0cdbd 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -16,7 +16,9 @@ extern int fail_migrate_page(struct address_space *,
struct page *, struct page *);
extern int migrate_prep(void);
-
+extern int migrate_vmas(struct mm_struct *mm,
+ const nodemask_t *from, const nodemask_t *to,
+ unsigned long flags);
#else
static inline int isolate_lru_page(struct page *p, struct list_head *list)
@@ -30,6 +32,13 @@ static inline int migrate_pages_to(struct list_head *pagelist,
static inline int migrate_prep(void) { return -ENOSYS; }
+static inline int migrate_vmas(struct mm_struct *mm,
+ const nodemask_t *from, const nodemask_t *to,
+ unsigned long flags)
+{
+ return -ENOSYS;
+}
+
/* Possible settings for the migrate_page() method in address_operations */
#define migrate_page NULL
#define fail_migrate_page NULL
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 71c5d2f667e..a929ea197e4 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -206,6 +206,8 @@ struct vm_operations_struct {
int (*set_policy)(struct vm_area_struct *vma, struct mempolicy *new);
struct mempolicy *(*get_policy)(struct vm_area_struct *vma,
unsigned long addr);
+ int (*migrate)(struct vm_area_struct *vma, const nodemask_t *from,
+ const nodemask_t *to, unsigned long flags);
#endif
};
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index ec4a1a950df..73e0f23b7f5 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -632,6 +632,10 @@ int do_migrate_pages(struct mm_struct *mm,
down_read(&mm->mmap_sem);
+ err = migrate_vmas(mm, from_nodes, to_nodes, flags);
+ if (err)
+ goto out;
+
/*
* Find a 'source' bit set in 'tmp' whose corresponding 'dest'
* bit in 'to' is not also set in 'tmp'. Clear the found 'source'
@@ -691,7 +695,7 @@ int do_migrate_pages(struct mm_struct *mm,
if (err < 0)
break;
}
-
+out:
up_read(&mm->mmap_sem);
if (err < 0)
return err;
diff --git a/mm/migrate.c b/mm/migrate.c
index 1c2a71aa05c..0576c053598 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -976,3 +976,23 @@ out2:
}
#endif
+/*
+ * Call migration functions in the vma_ops that may prepare
+ * memory in a vm for migration. migration functions may perform
+ * the migration for vmas that do not have an underlying page struct.
+ */
+int migrate_vmas(struct mm_struct *mm, const nodemask_t *to,
+ const nodemask_t *from, unsigned long flags)
+{
+ struct vm_area_struct *vma;
+ int err = 0;
+
+ for(vma = mm->mmap; vma->vm_next && !err; vma = vma->vm_next) {
+ if (vma->vm_ops && vma->vm_ops->migrate) {
+ err = vma->vm_ops->migrate(vma, to, from, flags);
+ if (err)
+ break;
+ }
+ }
+ return err;
+}