vmscan.c: fix invalid strict_strtoul() check in write_scan_unevictable_node()

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

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 7b0573f..ac644fe 100644 (file)
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -866,7 +866,15 @@ static unsigned long shrink_page_list(struct list_head *page_list,
                         */
                        if (page_is_file_cache(page) &&
                                        (!current_is_kswapd() || priority >= DEF_PRIORITY - 2)) {
-                               inc_zone_page_state(page, NR_VMSCAN_WRITE_SKIP);
+                               /*
+                                * Immediately reclaim when written back.
+                                * Similar in principal to deactivate_page()
+                                * except we already have the page isolated
+                                * and know it's dirty
+                                */
+                               inc_zone_page_state(page, NR_VMSCAN_IMMEDIATE);
+                               SetPageReclaim(page);
+
                                goto keep_locked;
                        }
 
@@ -2740,6 +2748,8 @@ out:
 
                        /* If balanced, clear the congested flag */
                        zone_clear_flag(zone, ZONE_CONGESTED);
+                       if (i <= *classzone_idx)
+                               balanced += zone->present_pages;
                }
        }
 
@@ -2813,7 +2823,9 @@ static void kswapd_try_to_sleep(pg_data_t *pgdat, int order, int classzone_idx)
 static int kswapd(void *p)
 {
        unsigned long order, new_order;
+       unsigned balanced_order;
        int classzone_idx, new_classzone_idx;
+       int balanced_classzone_idx;
        pg_data_t *pgdat = (pg_data_t*)p;
        struct task_struct *tsk = current;
 
@@ -2844,7 +2856,9 @@ static int kswapd(void *p)
        set_freezable();
 
        order = new_order = 0;
+       balanced_order = 0;
        classzone_idx = new_classzone_idx = pgdat->nr_zones - 1;
+       balanced_classzone_idx = classzone_idx;
        for ( ; ; ) {
                int ret;
 
@@ -2853,7 +2867,8 @@ static int kswapd(void *p)
                 * new request of a similar or harder type will succeed soon
                 * so consider going to sleep on the basis we reclaimed at
                 */
-               if (classzone_idx >= new_classzone_idx && order == new_order) {
+               if (balanced_classzone_idx >= new_classzone_idx &&
+                                       balanced_order == new_order) {
                        new_order = pgdat->kswapd_max_order;
                        new_classzone_idx = pgdat->classzone_idx;
                        pgdat->kswapd_max_order =  0;
@@ -2868,9 +2883,12 @@ static int kswapd(void *p)
                        order = new_order;
                        classzone_idx = new_classzone_idx;
                } else {
-                       kswapd_try_to_sleep(pgdat, order, classzone_idx);
+                       kswapd_try_to_sleep(pgdat, balanced_order,
+                                               balanced_classzone_idx);
                        order = pgdat->kswapd_max_order;
                        classzone_idx = pgdat->classzone_idx;
+                       new_order = order;
+                       new_classzone_idx = classzone_idx;
                        pgdat->kswapd_max_order = 0;
                        pgdat->classzone_idx = pgdat->nr_zones - 1;
                }
@@ -2885,7 +2903,9 @@ static int kswapd(void *p)
                 */
                if (!ret) {
                        trace_mm_vmscan_kswapd_wake(pgdat->node_id, order);
-                       order = balance_pgdat(pgdat, order, &classzone_idx);
+                       balanced_classzone_idx = classzone_idx;
+                       balanced_order = balance_pgdat(pgdat, order,
+                                               &balanced_classzone_idx);
                }
        }
        return 0;
@@ -3500,8 +3520,8 @@ static ssize_t write_scan_unevictable_node(struct sys_device *dev,
        unsigned long res;
        unsigned long req = strict_strtoul(buf, 10, &res);
 
-       if (!req)
-               return 1;       /* zero is no-op */
+       if (req || !res)
+               return 1; /* Invalid input or zero is no-op */
 
        for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
                if (!populated_zone(zone))