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 <linux/memory.h>
  13 #include <linux/notifier.h>
  14 #include "internal.h"
  15
  16 #ifdef CONFIG_DEBUG_MEMORY_INIT
  17 int mminit_loglevel;
  18
  19 #ifndef SECTIONS_SHIFT
  20 #define SECTIONS_SHIFT  0
  21 #endif
  22
  23 /* The zonelists are simply reported, validation is manual. */
  24 void mminit_verify_zonelist(void)
  25 {
  26         int nid;
  27
  28         if (mminit_loglevel < MMINIT_VERIFY)
  29                 return;
  30
  31         for_each_online_node(nid) {
  32                 pg_data_t *pgdat = NODE_DATA(nid);
  33                 struct zone *zone;
  34                 struct zoneref *z;
  35                 struct zonelist *zonelist;
  36                 int i, listid, zoneid;
  37
  38                 BUG_ON(MAX_ZONELISTS > 2);
  39                 for (i = 0; i < MAX_ZONELISTS * MAX_NR_ZONES; i++) {
  40
  41                         /* Identify the zone and nodelist */
  42                         zoneid = i % MAX_NR_ZONES;
  43                         listid = i / MAX_NR_ZONES;
  44                         zonelist = &pgdat->node_zonelists[listid];
  45                         zone = &pgdat->node_zones[zoneid];
  46                         if (!populated_zone(zone))
  47                                 continue;
  48
  49                         /* Print information about the zonelist */
  50                         printk(KERN_DEBUG "mminit::zonelist %s %d:%s = ",
  51                                 listid > 0 ? "thisnode" : "general", nid,
  52                                 zone->name);
  53
  54                         /* Iterate the zonelist */
  55                         for_each_zone_zonelist(zone, z, zonelist, zoneid) {
  56 #ifdef CONFIG_NUMA
  57                                 printk(KERN_CONT "%d:%s ",
  58                                         zone->node, zone->name);
  59 #else
  60                                 printk(KERN_CONT "0:%s ", zone->name);
  61 #endif /* CONFIG_NUMA */
  62                         }
  63                         printk(KERN_CONT "\n");
  64                 }
  65         }
  66 }
  67
  68 void __init mminit_verify_pageflags_layout(void)
  69 {
  70         int shift, width;
  71         unsigned long or_mask, add_mask;
  72
  73         shift = 8 * sizeof(unsigned long);
  74         width = shift - SECTIONS_WIDTH - NODES_WIDTH - ZONES_WIDTH - LAST_NID_SHIFT;
  75         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_widths",
  76                 "Section %d Node %d Zone %d Lastnid %d Flags %d\n",
  77                 SECTIONS_WIDTH,
  78                 NODES_WIDTH,
  79                 ZONES_WIDTH,
  80                 LAST_NID_WIDTH,
  81                 NR_PAGEFLAGS);
  82         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_shifts",
  83                 "Section %d Node %d Zone %d Lastnid %d\n",
  84                 SECTIONS_SHIFT,
  85                 NODES_SHIFT,
  86                 ZONES_SHIFT,
  87                 LAST_NID_SHIFT);
  88         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_pgshifts",
  89                 "Section %lu Node %lu Zone %lu Lastnid %lu\n",
  90                 (unsigned long)SECTIONS_PGSHIFT,
  91                 (unsigned long)NODES_PGSHIFT,
  92                 (unsigned long)ZONES_PGSHIFT,
  93                 (unsigned long)LAST_NID_PGSHIFT);
  94         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodezoneid",
  95                 "Node/Zone ID: %lu -> %lu\n",
  96                 (unsigned long)(ZONEID_PGOFF + ZONEID_SHIFT),
  97                 (unsigned long)ZONEID_PGOFF);
  98         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_usage",
  99                 "location: %d -> %d layout %d -> %d unused %d -> %d page-flags\n",
 100                 shift, width, width, NR_PAGEFLAGS, NR_PAGEFLAGS, 0);
 101 #ifdef NODE_NOT_IN_PAGE_FLAGS
 102         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodeflags",
 103                 "Node not in page flags");
 104 #endif
 105 #ifdef LAST_NID_NOT_IN_PAGE_FLAGS
 106         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodeflags",
 107                 "Last nid not in page flags");
 108 #endif
 109
 110         if (SECTIONS_WIDTH) {
 111                 shift -= SECTIONS_WIDTH;
 112                 BUG_ON(shift != SECTIONS_PGSHIFT);
 113         }
 114         if (NODES_WIDTH) {
 115                 shift -= NODES_WIDTH;
 116                 BUG_ON(shift != NODES_PGSHIFT);
 117         }
 118         if (ZONES_WIDTH) {
 119                 shift -= ZONES_WIDTH;
 120                 BUG_ON(shift != ZONES_PGSHIFT);
 121         }
 122
 123         /* Check for bitmask overlaps */
 124         or_mask = (ZONES_MASK << ZONES_PGSHIFT) |
 125                         (NODES_MASK << NODES_PGSHIFT) |
 126                         (SECTIONS_MASK << SECTIONS_PGSHIFT);
 127         add_mask = (ZONES_MASK << ZONES_PGSHIFT) +
 128                         (NODES_MASK << NODES_PGSHIFT) +
 129                         (SECTIONS_MASK << SECTIONS_PGSHIFT);
 130         BUG_ON(or_mask != add_mask);
 131 }
 132
 133 void __meminit mminit_verify_page_links(struct page *page, enum zone_type zone,
 134                         unsigned long nid, unsigned long pfn)
 135 {
 136         BUG_ON(page_to_nid(page) != nid);
 137         BUG_ON(page_zonenum(page) != zone);
 138         BUG_ON(page_to_pfn(page) != pfn);
 139 }
 140
 141 static __init int set_mminit_loglevel(char *str)
 142 {
 143         get_option(&str, &mminit_loglevel);
 144         return 0;
 145 }
 146 early_param("mminit_loglevel", set_mminit_loglevel);
 147 #endif /* CONFIG_DEBUG_MEMORY_INIT */
 148
 149 struct kobject *mm_kobj;
 150 EXPORT_SYMBOL_GPL(mm_kobj);
 151
 152 #ifdef CONFIG_SMP
 153 s32 vm_committed_as_batch = 32;
 154
 155 static void __meminit mm_compute_batch(void)
 156 {
 157         u64 memsized_batch;
 158         s32 nr = num_present_cpus();
 159         s32 batch = max_t(s32, nr*2, 32);
 160
 161         /* batch size set to 0.4% of (total memory/#cpus), or max int32 */
 162         memsized_batch = min_t(u64, (totalram_pages/nr)/256, 0x7fffffff);
 163
 164         vm_committed_as_batch = max_t(s32, memsized_batch, batch);
 165 }
 166
 167 static int __meminit mm_compute_batch_notifier(struct notifier_block *self,
 168                                         unsigned long action, void *arg)
 169 {
 170         switch (action) {
 171         case MEM_ONLINE:
 172         case MEM_OFFLINE:
 173                 mm_compute_batch();
 174         default:
 175                 break;
 176         }
 177         return NOTIFY_OK;
 178 }
 179
 180 static struct notifier_block compute_batch_nb __meminitdata = {
 181         .notifier_call = mm_compute_batch_notifier,
 182         .priority = IPC_CALLBACK_PRI, /* use lowest priority */
 183 };
 184
 185 static int __init mm_compute_batch_init(void)
 186 {
 187         mm_compute_batch();
 188         register_hotmemory_notifier(&compute_batch_nb);
 189
 190         return 0;
 191 }
 192
 193 __initcall(mm_compute_batch_init);
 194
 195 #endif
 196
 197 static int __init mm_sysfs_init(void)
 198 {
 199         mm_kobj = kobject_create_and_add("mm", kernel_kobj);
 200         if (!mm_kobj)
 201                 return -ENOMEM;
 202
 203         return 0;
 204 }
 205
 206 __initcall(mm_sysfs_init);