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