mm/page_alloc.c: recalculate some of node threshold when on/offline memory

Some of node threshold depends on number of managed pages in the node.
When memory is going on/offline, it can be changed and we need to adjust
them.

Add recalculation to appropriate places and clean-up related functions
for better maintenance.

Link: http://lkml.kernel.org/r/1470724248-26780-2-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 35 insertions, 15 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 9a92718b1103..ab2c0ff8c2e6 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4757,6 +4757,8 @@ int local_memory_node(int node)
 }
 #endif
 
+static void setup_min_unmapped_ratio(void);
+static void setup_min_slab_ratio(void);
 #else   /* CONFIG_NUMA */
 
 static void set_zonelist_order(void)
@@ -5878,9 +5880,6 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat)
                 zone->managed_pages = is_highmem_idx(j) ? realsize : freesize;
 #ifdef CONFIG_NUMA
                 zone->node = nid;
-                pgdat->min_unmapped_pages += (freesize*sysctl_min_unmapped_ratio)
-                                                / 100;
-                pgdat->min_slab_pages += (freesize * sysctl_min_slab_ratio) / 100;
 #endif
                 zone->name = zone_names[j];
                 zone->zone_pgdat = pgdat;
@@ -6801,6 +6800,12 @@ int __meminit init_per_zone_wmark_min(void)
         setup_per_zone_wmarks();
         refresh_zone_stat_thresholds();
         setup_per_zone_lowmem_reserve();
+
+#ifdef CONFIG_NUMA
+        setup_min_unmapped_ratio();
+        setup_min_slab_ratio();
+#endif
+
         return 0;
 }
 core_initcall(init_per_zone_wmark_min)
@@ -6842,16 +6847,10 @@ int watermark_scale_factor_sysctl_handler(struct ctl_table *table, int write,
 }
 
 #ifdef CONFIG_NUMA
-int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
-        void __user *buffer, size_t *length, loff_t *ppos)
+static void setup_min_unmapped_ratio(void)
 {
-        struct pglist_data *pgdat;
+        pg_data_t *pgdat;
         struct zone *zone;
-        int rc;
-
-        rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
-        if (rc)
-                return rc;
 
         for_each_online_pgdat(pgdat)
                 pgdat->min_unmapped_pages = 0;
@@ -6859,26 +6858,47 @@ int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
         for_each_zone(zone)
                 zone->zone_pgdat->min_unmapped_pages += (zone->managed_pages *
                                 sysctl_min_unmapped_ratio) / 100;
-        return 0;
 }
 
-int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
+
+int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
         void __user *buffer, size_t *length, loff_t *ppos)
 {
-        struct pglist_data *pgdat;
-        struct zone *zone;
         int rc;
 
         rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
         if (rc)
                 return rc;
 
+        setup_min_unmapped_ratio();
+
+        return 0;
+}
+
+static void setup_min_slab_ratio(void)
+{
+        pg_data_t *pgdat;
+        struct zone *zone;
+
         for_each_online_pgdat(pgdat)
                 pgdat->min_slab_pages = 0;
 
         for_each_zone(zone)
                 zone->zone_pgdat->min_slab_pages += (zone->managed_pages *
                                 sysctl_min_slab_ratio) / 100;
+}
+
+int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
+        void __user *buffer, size_t *length, loff_t *ppos)
+{
+        int rc;
+
+        rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
+        if (rc)
+                return rc;
+
+        setup_min_slab_ratio();
+
         return 0;
 }
 #endif