* Try to allocate it some swap space here.
*/
if (PageAnon(page) && !PageSwapCache(page)) {
- if (!add_to_swap(page))
+ if (!add_to_swap(page, GFP_ATOMIC))
goto activate_locked;
}
#endif /* CONFIG_SWAP */
}
#ifdef CONFIG_MIGRATION
+static inline void move_to_lru(struct page *page)
+{
+ list_del(&page->lru);
+ if (PageActive(page)) {
+ /*
+ * lru_cache_add_active checks that
+ * the PG_active bit is off.
+ */
+ ClearPageActive(page);
+ lru_cache_add_active(page);
+ } else {
+ lru_cache_add(page);
+ }
+ put_page(page);
+}
+
+/*
+ * Add isolated pages on the list back to the LRU
+ *
+ * returns the number of pages put back.
+ */
+int putback_lru_pages(struct list_head *l)
+{
+ struct page *page;
+ struct page *page2;
+ int count = 0;
+
+ list_for_each_entry_safe(page, page2, l, lru) {
+ move_to_lru(page);
+ count++;
+ }
+ return count;
+}
+
/*
* swapout a single page
* page is locked upon entry, unlocked on exit
- *
- * return codes:
- * 0 = complete
- * 1 = retry
*/
static int swap_page(struct page *page)
{
unlock_page(page);
retry:
- return 1;
+ return -EAGAIN;
}
/*
* migrate_pages
* is only swapping out pages and never touches the second
* list. The direct migration patchset
* extends this function to avoid the use of swap.
+ *
+ * Return: Number of pages not migrated when "to" ran empty.
*/
-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;
struct page *page2;
int swapwrite = current->flags & PF_SWAPWRITE;
+ int rc;
if (!swapwrite)
current->flags |= PF_SWAPWRITE;
redo:
retry = 0;
- list_for_each_entry_safe(page, page2, l, lru) {
+ list_for_each_entry_safe(page, page2, from, lru) {
cond_resched();
+ rc = 0;
+ if (page_count(page) == 1)
+ /* page was freed from under us. So we are done. */
+ goto next;
+
/*
* Skip locked pages during the first two passes to give the
* functions holding the lock time to release the page. Later we
* use lock_page() to have a higher chance of acquiring the
* lock.
*/
+ rc = -EAGAIN;
if (pass > 2)
lock_page(page);
else
if (TestSetPageLocked(page))
- goto retry_later;
+ goto next;
/*
* Only wait on writeback if we have already done a pass where
if (pass > 0) {
wait_on_page_writeback(page);
} else {
- if (PageWriteback(page)) {
- unlock_page(page);
- goto retry_later;
- }
+ if (PageWriteback(page))
+ goto unlock_page;
}
+ /*
+ * Anonymous pages must have swap cache references otherwise
+ * the information contained in the page maps cannot be
+ * preserved.
+ */
if (PageAnon(page) && !PageSwapCache(page)) {
- if (!add_to_swap(page)) {
- unlock_page(page);
- list_move(&page->lru, &failed);
- nr_failed++;
- continue;
+ if (!add_to_swap(page, GFP_KERNEL)) {
+ rc = -ENOMEM;
+ goto unlock_page;
}
}
* Page is properly locked and writeback is complete.
* Try to migrate the page.
*/
- if (!swap_page(page))
- continue;
-retry_later:
- retry++;
+ rc = swap_page(page);
+ goto next;
+
+unlock_page:
+ unlock_page(page);
+
+next:
+ if (rc == -EAGAIN) {
+ retry++;
+ } else if (rc) {
+ /* Permanent failure */
+ list_move(&page->lru, failed);
+ nr_failed++;
+ } else {
+ /* Success */
+ list_move(&page->lru, moved);
+ }
}
if (retry && pass++ < 10)
goto redo;
if (!swapwrite)
current->flags &= ~PF_SWAPWRITE;
- if (!list_empty(&failed))
- list_splice(&failed, l);
-
return nr_failed + retry;
}
+
+static void lru_add_drain_per_cpu(void *dummy)
+{
+ lru_add_drain();
+}
+
+/*
+ * Isolate one page from the LRU lists and put it on the
+ * indicated list. Do necessary cache draining if the
+ * page is not on the LRU lists yet.
+ *
+ * Result:
+ * 0 = page not on LRU list
+ * 1 = page removed from LRU list and added to the specified list.
+ * -ENOENT = page is being freed elsewhere.
+ */
+int isolate_lru_page(struct page *page)
+{
+ int rc = 0;
+ struct zone *zone = page_zone(page);
+
+redo:
+ spin_lock_irq(&zone->lru_lock);
+ rc = __isolate_lru_page(page);
+ if (rc == 1) {
+ if (PageActive(page))
+ del_page_from_active_list(zone, page);
+ else
+ del_page_from_inactive_list(zone, page);
+ }
+ spin_unlock_irq(&zone->lru_lock);
+ if (rc == 0) {
+ /*
+ * Maybe this page is still waiting for a cpu to drain it
+ * from one of the lru lists?
+ */
+ rc = schedule_on_each_cpu(lru_add_drain_per_cpu, NULL);
+ if (rc == 0 && PageLRU(page))
+ goto redo;
+ }
+ return rc;
+}
#endif
/*
return nr_taken;
}
-static void lru_add_drain_per_cpu(void *dummy)
-{
- lru_add_drain();
-}
-
-/*
- * Isolate one page from the LRU lists and put it on the
- * indicated list. Do necessary cache draining if the
- * page is not on the LRU lists yet.
- *
- * Result:
- * 0 = page not on LRU list
- * 1 = page removed from LRU list and added to the specified list.
- * -ENOENT = page is being freed elsewhere.
- */
-int isolate_lru_page(struct page *page)
-{
- int rc = 0;
- struct zone *zone = page_zone(page);
-
-redo:
- spin_lock_irq(&zone->lru_lock);
- rc = __isolate_lru_page(page);
- if (rc == 1) {
- if (PageActive(page))
- del_page_from_active_list(zone, page);
- else
- del_page_from_inactive_list(zone, page);
- }
- spin_unlock_irq(&zone->lru_lock);
- if (rc == 0) {
- /*
- * Maybe this page is still waiting for a cpu to drain it
- * from one of the lru lists?
- */
- rc = schedule_on_each_cpu(lru_add_drain_per_cpu, NULL);
- if (rc == 0 && PageLRU(page))
- goto redo;
- }
- return rc;
-}
-
/*
* shrink_cache() adds the number of pages reclaimed to sc->nr_reclaimed
*/
pagevec_release(&pvec);
}
-static inline void move_to_lru(struct page *page)
-{
- list_del(&page->lru);
- if (PageActive(page)) {
- /*
- * lru_cache_add_active checks that
- * the PG_active bit is off.
- */
- ClearPageActive(page);
- lru_cache_add_active(page);
- } else {
- lru_cache_add(page);
- }
- put_page(page);
-}
-
-/*
- * Add isolated pages on the list back to the LRU
- *
- * returns the number of pages put back.
- */
-int putback_lru_pages(struct list_head *l)
-{
- struct page *page;
- struct page *page2;
- int count = 0;
-
- list_for_each_entry_safe(page, page2, l, lru) {
- move_to_lru(page);
- count++;
- }
- return count;
-}
-
/*
* This moves pages from the active list to the inactive list.
*
projects / mv-sheeva.git / blobdiff