SHM_UNLOCK: fix long unpreemptible section

[pandora-kernel.git] / mm / vmscan.c

diff --git a/mm/vmscan.c b/mm/vmscan.c
index f54a05b..824676a 100644 (file)
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -3353,6 +3353,7 @@ int page_evictable(struct page *page, struct vm_area_struct *vma)
        return 1;
 }
 
+#ifdef CONFIG_SHMEM
 /**
  * check_move_unevictable_page - check page for evictability and move to appropriate zone lru list
  * @page: page to check evictability and move to appropriate lru list
@@ -3363,6 +3364,8 @@ int page_evictable(struct page *page, struct vm_area_struct *vma)
  *
  * Restrictions: zone->lru_lock must be held, page must be on LRU and must
  * have PageUnevictable set.
+ *
+ * This function is only used for SysV IPC SHM_UNLOCK.
  */
 static void check_move_unevictable_page(struct page *page, struct zone *zone)
 {
@@ -3396,6 +3399,8 @@ retry:
  *
  * Scan all pages in mapping.  Check unevictable pages for
  * evictability and move them to the appropriate zone lru list.
+ *
+ * This function is only used for SysV IPC SHM_UNLOCK.
  */
 void scan_mapping_unevictable_pages(struct address_space *mapping)
 {
@@ -3441,9 +3446,14 @@ void scan_mapping_unevictable_pages(struct address_space *mapping)
                pagevec_release(&pvec);
 
                count_vm_events(UNEVICTABLE_PGSCANNED, pg_scanned);
+               cond_resched();
        }
-
 }
+#else
+void scan_mapping_unevictable_pages(struct address_space *mapping)
+{
+}
+#endif /* CONFIG_SHMEM */
 
 static void warn_scan_unevictable_pages(void)
 {