[PATCH] SwapMig: Extend parameters for migrate_pages()
Extend the parameters of migrate_pages() to allow the caller control over the
fate of successfully migrated or impossible to migrate pages.
Swap migration and direct migration will have the same interface after this
patch so that patches can be independently applied to the policy layer and the
core migration code.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/swap.h b/include/linux/swap.h
index eb591ea..389d1c3 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -178,7 +178,8 @@
#ifdef CONFIG_MIGRATION
extern int isolate_lru_page(struct page *p);
extern int putback_lru_pages(struct list_head *l);
-extern int migrate_pages(struct list_head *l, struct list_head *t);
+extern int migrate_pages(struct list_head *l, struct list_head *t,
+ struct list_head *moved, struct list_head *failed);
#endif
#ifdef CONFIG_MMU
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 20d5ad3..30bdafb 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -429,6 +429,19 @@
return mpol_check_policy(mode, nodes);
}
+static int swap_pages(struct list_head *pagelist)
+{
+ LIST_HEAD(moved);
+ LIST_HEAD(failed);
+ int n;
+
+ n = migrate_pages(pagelist, NULL, &moved, &failed);
+ putback_lru_pages(&failed);
+ putback_lru_pages(&moved);
+
+ return n;
+}
+
long do_mbind(unsigned long start, unsigned long len,
unsigned long mode, nodemask_t *nmask, unsigned long flags)
{
@@ -481,10 +494,13 @@
(flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) ? &pagelist : NULL);
err = PTR_ERR(vma);
if (!IS_ERR(vma)) {
+ int nr_failed = 0;
+
err = mbind_range(vma, start, end, new);
if (!list_empty(&pagelist))
- migrate_pages(&pagelist, NULL);
- if (!err && !list_empty(&pagelist) && (flags & MPOL_MF_STRICT))
+ nr_failed = swap_pages(&pagelist);
+
+ if (!err && nr_failed && (flags & MPOL_MF_STRICT))
err = -EIO;
}
if (!list_empty(&pagelist))
@@ -635,11 +651,12 @@
down_read(&mm->mmap_sem);
check_range(mm, mm->mmap->vm_start, TASK_SIZE, &nodes,
flags | MPOL_MF_DISCONTIG_OK, &pagelist);
+
if (!list_empty(&pagelist)) {
- migrate_pages(&pagelist, NULL);
- if (!list_empty(&pagelist))
- count = putback_lru_pages(&pagelist);
+ count = swap_pages(&pagelist);
+ putback_lru_pages(&pagelist);
}
+
up_read(&mm->mmap_sem);
return count;
}
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 73ba404..5eecb51 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -670,10 +670,10 @@
* list. The direct migration patchset
* extends this function to avoid the use of swap.
*/
-int migrate_pages(struct list_head *l, struct list_head *t)
+int migrate_pages(struct list_head *from, struct list_head *to,
+ struct list_head *moved, struct list_head *failed)
{
int retry;
- LIST_HEAD(failed);
int nr_failed = 0;
int pass = 0;
struct page *page;
@@ -686,12 +686,12 @@
redo:
retry = 0;
- list_for_each_entry_safe(page, page2, l, lru) {
+ list_for_each_entry_safe(page, page2, from, lru) {
cond_resched();
if (page_count(page) == 1) {
/* page was freed from under us. So we are done. */
- move_to_lru(page);
+ list_move(&page->lru, moved);
continue;
}
/*
@@ -722,7 +722,7 @@
if (PageAnon(page) && !PageSwapCache(page)) {
if (!add_to_swap(page, GFP_KERNEL)) {
unlock_page(page);
- list_move(&page->lru, &failed);
+ list_move(&page->lru, failed);
nr_failed++;
continue;
}
@@ -732,8 +732,10 @@
* Page is properly locked and writeback is complete.
* Try to migrate the page.
*/
- if (!swap_page(page))
+ if (!swap_page(page)) {
+ list_move(&page->lru, moved);
continue;
+ }
retry_later:
retry++;
}
@@ -743,9 +745,6 @@
if (!swapwrite)
current->flags &= ~PF_SWAPWRITE;
- if (!list_empty(&failed))
- list_splice(&failed, l);
-
return nr_failed + retry;
}