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                                 pr_cont("%d:%s ", zone_to_nid(zone), zone->name);
  58                         pr_cont("\n");
  59                 }
  60         }
  61 }
  62
  63 void __init mminit_verify_pageflags_layout(void)
  64 {
  65         int shift, width;
  66         unsigned long or_mask, add_mask;
  67
  68         shift = 8 * sizeof(unsigned long);
  69         width = shift - SECTIONS_WIDTH - NODES_WIDTH - ZONES_WIDTH - LAST_CPUPID_SHIFT;
  70         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_widths",
  71                 "Section %d Node %d Zone %d Lastcpupid %d Flags %d\n",
  72                 SECTIONS_WIDTH,
  73                 NODES_WIDTH,
  74                 ZONES_WIDTH,
  75                 LAST_CPUPID_WIDTH,
  76                 NR_PAGEFLAGS);
  77         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_shifts",
  78                 "Section %d Node %d Zone %d Lastcpupid %d\n",
  79                 SECTIONS_SHIFT,
  80                 NODES_SHIFT,
  81                 ZONES_SHIFT,
  82                 LAST_CPUPID_SHIFT);
  83         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_pgshifts",
  84                 "Section %lu Node %lu Zone %lu Lastcpupid %lu\n",
  85                 (unsigned long)SECTIONS_PGSHIFT,
  86                 (unsigned long)NODES_PGSHIFT,
  87                 (unsigned long)ZONES_PGSHIFT,
  88                 (unsigned long)LAST_CPUPID_PGSHIFT);
  89         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodezoneid",
  90                 "Node/Zone ID: %lu -> %lu\n",
  91                 (unsigned long)(ZONEID_PGOFF + ZONEID_SHIFT),
  92                 (unsigned long)ZONEID_PGOFF);
  93         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_usage",
  94                 "location: %d -> %d layout %d -> %d unused %d -> %d page-flags\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 #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
 101         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodeflags",
 102                 "Last cpupid not in page flags");
 103 #endif
 104
 105         if (SECTIONS_WIDTH) {
 106                 shift -= SECTIONS_WIDTH;
 107                 BUG_ON(shift != SECTIONS_PGSHIFT);
 108         }
 109         if (NODES_WIDTH) {
 110                 shift -= NODES_WIDTH;
 111                 BUG_ON(shift != NODES_PGSHIFT);
 112         }
 113         if (ZONES_WIDTH) {
 114                 shift -= ZONES_WIDTH;
 115                 BUG_ON(shift != ZONES_PGSHIFT);
 116         }
 117
 118         /* Check for bitmask overlaps */
 119         or_mask = (ZONES_MASK << ZONES_PGSHIFT) |
 120                         (NODES_MASK << NODES_PGSHIFT) |
 121                         (SECTIONS_MASK << SECTIONS_PGSHIFT);
 122         add_mask = (ZONES_MASK << ZONES_PGSHIFT) +
 123                         (NODES_MASK << NODES_PGSHIFT) +
 124                         (SECTIONS_MASK << SECTIONS_PGSHIFT);
 125         BUG_ON(or_mask != add_mask);
 126 }
 127
 128 static __init int set_mminit_loglevel(char *str)
 129 {
 130         get_option(&str, &mminit_loglevel);
 131         return 0;
 132 }
 133 early_param("mminit_loglevel", set_mminit_loglevel);
 134 #endif /* CONFIG_DEBUG_MEMORY_INIT */
 135
 136 struct kobject *mm_kobj;
 137 EXPORT_SYMBOL_GPL(mm_kobj);
 138
 139 #ifdef CONFIG_SMP
 140 s32 vm_committed_as_batch = 32;
 141
 142 static void __meminit mm_compute_batch(void)
 143 {
 144         u64 memsized_batch;
 145         s32 nr = num_present_cpus();
 146         s32 batch = max_t(s32, nr*2, 32);
 147
 148         /* batch size set to 0.4% of (total memory/#cpus), or max int32 */
 149         memsized_batch = min_t(u64, (totalram_pages()/nr)/256, 0x7fffffff);
 150
 151         vm_committed_as_batch = max_t(s32, memsized_batch, batch);
 152 }
 153
 154 static int __meminit mm_compute_batch_notifier(struct notifier_block *self,
 155                                         unsigned long action, void *arg)
 156 {
 157         switch (action) {
 158         case MEM_ONLINE:
 159         case MEM_OFFLINE:
 160                 mm_compute_batch();
 161         default:
 162                 break;
 163         }
 164         return NOTIFY_OK;
 165 }
 166
 167 static struct notifier_block compute_batch_nb __meminitdata = {
 168         .notifier_call = mm_compute_batch_notifier,
 169         .priority = IPC_CALLBACK_PRI, /* use lowest priority */
 170 };
 171
 172 static int __init mm_compute_batch_init(void)
 173 {
 174         mm_compute_batch();
 175         register_hotmemory_notifier(&compute_batch_nb);
 176
 177         return 0;
 178 }
 179
 180 __initcall(mm_compute_batch_init);
 181
 182 #endif
 183
 184 static int __init mm_sysfs_init(void)
 185 {
 186         mm_kobj = kobject_create_and_add("mm", kernel_kobj);
 187         if (!mm_kobj)
 188                 return -ENOMEM;
 189
 190         return 0;
 191 }
 192 postcore_initcall(mm_sysfs_init);