1 files changed, 15 insertions, 3 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 078cf920208a..b0cd81c32de6 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -201,13 +201,25 @@ static int shrink_slab(unsigned long scanned, gfp_t gfp_mask,
         list_for_each_entry(shrinker, &shrinker_list, list) {
                 unsigned long long delta;
                 unsigned long total_scan;
+                unsigned long max_pass = (*shrinker->shrinker)(0, gfp_mask);
 
                 delta = (4 * scanned) / shrinker->seeks;
-                delta *= (*shrinker->shrinker)(0, gfp_mask);
+                delta *= max_pass;
                 do_div(delta, lru_pages + 1);
                 shrinker->nr += delta;
-                if (shrinker->nr < 0)
-                        shrinker->nr = LONG_MAX;        /* It wrapped! */
+                if (shrinker->nr < 0) {
+                        printk(KERN_ERR "%s: nr=%ld\n",
+                                        __FUNCTION__, shrinker->nr);
+                        shrinker->nr = max_pass;
+                }
+
+                /*
+                 * Avoid risking looping forever due to too large nr value:
+                 * never try to free more than twice the estimate number of
+                 * freeable entries.
+                 */
+                if (shrinker->nr > max_pass * 2)
+                        shrinker->nr = max_pass * 2;
 
                 total_scan = shrinker->nr;
                 shrinker->nr = 0;