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>

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 9a92718b1103aae45f8b0f68e7be7431f98a5f5c..ab2c0ff8c2e6ae4eebd1b2f715b1dcb11d593777 100644 (file)
--- 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