mm/mm_init.c

   1 /*
   2  * mm_init.c - Memory initialisation verification and debugging
   3  *
   4  * Copyright 2008 IBM Corporation, 2008
   5  * Author Mel Gorman <mel@csn.ul.ie>
   6  *
   7  */
   8 #include <linux/kernel.h>
   9 #include <linux/init.h>
  10 #include <linux/kobject.h>
  11 #include <linux/export.h>
  12 #include "internal.h"
  13
  14 #ifdef CONFIG_DEBUG_MEMORY_INIT
  15 int mminit_loglevel;
  16
  17 #ifndef SECTIONS_SHIFT
  18 #define SECTIONS_SHIFT  0
  19 #endif
  20
  21 /* The zonelists are simply reported, validation is manual. */
  22 void mminit_verify_zonelist(void)
  23 {
  24         int nid;
  25
  26         if (mminit_loglevel < MMINIT_VERIFY)
  27                 return;
  28
  29         for_each_online_node(nid) {
  30                 pg_data_t *pgdat = NODE_DATA(nid);
  31                 struct zone *zone;
  32                 struct zoneref *z;
  33                 struct zonelist *zonelist;
  34                 int i, listid, zoneid;
  35
  36                 BUG_ON(MAX_ZONELISTS > 2);
  37                 for (i = 0; i < MAX_ZONELISTS * MAX_NR_ZONES; i++) {
  38
  39                         /* Identify the zone and nodelist */
  40                         zoneid = i % MAX_NR_ZONES;
  41                         listid = i / MAX_NR_ZONES;
  42                         zonelist = &pgdat->node_zonelists[listid];
  43                         zone = &pgdat->node_zones[zoneid];
  44                         if (!populated_zone(zone))
  45                                 continue;
  46
  47                         /* Print information about the zonelist */
  48                         printk(KERN_DEBUG "mminit::zonelist %s %d:%s = ",
  49                                 listid > 0 ? "thisnode" : "general", nid,
  50                                 zone->name);
  51
  52                         /* Iterate the zonelist */
  53                         for_each_zone_zonelist(zone, z, zonelist, zoneid) {
  54 #ifdef CONFIG_NUMA
  55                                 printk(KERN_CONT "%d:%s ",
  56                                         zone->node, zone->name);
  57 #else
  58                                 printk(KERN_CONT "0:%s ", zone->name);
  59 #endif /* CONFIG_NUMA */
  60                         }
  61                         printk(KERN_CONT "\n");
  62                 }
  63         }
  64 }
  65
  66 void __init mminit_verify_pageflags_layout(void)
  67 {
  68         int shift, width;
  69         unsigned long or_mask, add_mask;
  70
  71         shift = 8 * sizeof(unsigned long);
  72         width = shift - SECTIONS_WIDTH - NODES_WIDTH - ZONES_WIDTH;
  73         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_widths",
  74                 "Section %d Node %d Zone %d Flags %d\n",
  75                 SECTIONS_WIDTH,
  76                 NODES_WIDTH,
  77                 ZONES_WIDTH,
  78                 NR_PAGEFLAGS);
  79         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_shifts",
  80                 "Section %d Node %d Zone %d\n",
  81                 SECTIONS_SHIFT,
  82                 NODES_SHIFT,
  83                 ZONES_SHIFT);
  84         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_offsets",
  85                 "Section %lu Node %lu Zone %lu\n",
  86                 (unsigned long)SECTIONS_PGSHIFT,
  87                 (unsigned long)NODES_PGSHIFT,
  88                 (unsigned long)ZONES_PGSHIFT);
  89         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_zoneid",
  90                 "Zone ID: %lu -> %lu\n",
  91                 (unsigned long)ZONEID_PGOFF,
  92                 (unsigned long)(ZONEID_PGOFF + ZONEID_SHIFT));
  93         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_usage",
  94                 "location: %d -> %d unused %d -> %d flags %d -> %d\n",
  95                 shift, width, width, NR_PAGEFLAGS, NR_PAGEFLAGS, 0);
  96 #ifdef NODE_NOT_IN_PAGE_FLAGS
  97         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodeflags",
  98                 "Node not in page flags");
  99 #endif
 100
 101         if (SECTIONS_WIDTH) {
 102                 shift -= SECTIONS_WIDTH;
 103                 BUG_ON(shift != SECTIONS_PGSHIFT);
 104         }
 105         if (NODES_WIDTH) {
 106                 shift -= NODES_WIDTH;
 107                 BUG_ON(shift != NODES_PGSHIFT);
 108         }
 109         if (ZONES_WIDTH) {
 110                 shift -= ZONES_WIDTH;
 111                 BUG_ON(shift != ZONES_PGSHIFT);
 112         }
 113
 114         /* Check for bitmask overlaps */
 115         or_mask = (ZONES_MASK << ZONES_PGSHIFT) |
 116                         (NODES_MASK << NODES_PGSHIFT) |
 117                         (SECTIONS_MASK << SECTIONS_PGSHIFT);
 118         add_mask = (ZONES_MASK << ZONES_PGSHIFT) +
 119                         (NODES_MASK << NODES_PGSHIFT) +
 120                         (SECTIONS_MASK << SECTIONS_PGSHIFT);
 121         BUG_ON(or_mask != add_mask);
 122 }
 123
 124 void __meminit mminit_verify_page_links(struct page *page, enum zone_type zone,
 125                         unsigned long nid, unsigned long pfn)
 126 {
 127         BUG_ON(page_to_nid(page) != nid);
 128         BUG_ON(page_zonenum(page) != zone);
 129         BUG_ON(page_to_pfn(page) != pfn);
 130 }
 131
 132 static __init int set_mminit_loglevel(char *str)
 133 {
 134         get_option(&str, &mminit_loglevel);
 135         return 0;
 136 }
 137 early_param("mminit_loglevel", set_mminit_loglevel);
 138 #endif /* CONFIG_DEBUG_MEMORY_INIT */
 139
 140 struct kobject *mm_kobj;
 141 EXPORT_SYMBOL_GPL(mm_kobj);
 142
 143 static int __init mm_sysfs_init(void)
 144 {
 145         mm_kobj = kobject_create_and_add("mm", kernel_kobj);
 146         if (!mm_kobj)
 147                 return -ENOMEM;
 148
 149         return 0;
 150 }
 151
 152 __initcall(mm_sysfs_init);