mm/mm_init.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * mm_init.c - Memory initialisation verification and debugging
   4  *
   5  * Copyright 2008 IBM Corporation, 2008
   6  * Author Mel Gorman <mel@csn.ul.ie>
   7  *
   8  */
   9 #include <linux/kernel.h>
  10 #include <linux/init.h>
  11 #include <linux/kobject.h>
  12 #include <linux/export.h>
  13 #include <linux/memory.h>
  14 #include <linux/notifier.h>
  15 #include <linux/sched.h>
  16 #include "internal.h"
  17
  18 #ifdef CONFIG_DEBUG_MEMORY_INIT
  19 int __meminitdata mminit_loglevel;
  20
  21 #ifndef SECTIONS_SHIFT
  22 #define SECTIONS_SHIFT  0
  23 #endif
  24
  25 /* The zonelists are simply reported, validation is manual. */
  26 void __init mminit_verify_zonelist(void)
  27 {
  28         int nid;
  29
  30         if (mminit_loglevel < MMINIT_VERIFY)
  31                 return;
  32
  33         for_each_online_node(nid) {
  34                 pg_data_t *pgdat = NODE_DATA(nid);
  35                 struct zone *zone;
  36                 struct zoneref *z;
  37                 struct zonelist *zonelist;
  38                 int i, listid, zoneid;
  39
  40                 BUILD_BUG_ON(MAX_ZONELISTS > 2);
  41                 for (i = 0; i < MAX_ZONELISTS * MAX_NR_ZONES; i++) {
  42
  43                         /* Identify the zone and nodelist */
  44                         zoneid = i % MAX_NR_ZONES;
  45                         listid = i / MAX_NR_ZONES;
  46                         zonelist = &pgdat->node_zonelists[listid];
  47                         zone = &pgdat->node_zones[zoneid];
  48                         if (!populated_zone(zone))
  49                                 continue;
  50
  51                         /* Print information about the zonelist */
  52                         printk(KERN_DEBUG "mminit::zonelist %s %d:%s = ",
  53                                 listid > 0 ? "thisnode" : "general", nid,
  54                                 zone->name);
  55
  56                         /* Iterate the zonelist */
  57                         for_each_zone_zonelist(zone, z, zonelist, zoneid)
  58                                 pr_cont("%d:%s ", zone_to_nid(zone), zone->name);
  59                         pr_cont("\n");
  60                 }
  61         }
  62 }
  63
  64 void __init mminit_verify_pageflags_layout(void)
  65 {
  66         int shift, width;
  67         unsigned long or_mask, add_mask;
  68
  69         shift = 8 * sizeof(unsigned long);
  70         width = shift - SECTIONS_WIDTH - NODES_WIDTH - ZONES_WIDTH - LAST_CPUPID_SHIFT;
  71         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_widths",
  72                 "Section %d Node %d Zone %d Lastcpupid %d Flags %d\n",
  73                 SECTIONS_WIDTH,
  74                 NODES_WIDTH,
  75                 ZONES_WIDTH,
  76                 LAST_CPUPID_WIDTH,
  77                 NR_PAGEFLAGS);
  78         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_shifts",
  79                 "Section %d Node %d Zone %d Lastcpupid %d\n",
  80                 SECTIONS_SHIFT,
  81                 NODES_SHIFT,
  82                 ZONES_SHIFT,
  83                 LAST_CPUPID_SHIFT);
  84         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_pgshifts",
  85                 "Section %lu Node %lu Zone %lu Lastcpupid %lu\n",
  86                 (unsigned long)SECTIONS_PGSHIFT,
  87                 (unsigned long)NODES_PGSHIFT,
  88                 (unsigned long)ZONES_PGSHIFT,
  89                 (unsigned long)LAST_CPUPID_PGSHIFT);
  90         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodezoneid",
  91                 "Node/Zone ID: %lu -> %lu\n",
  92                 (unsigned long)(ZONEID_PGOFF + ZONEID_SHIFT),
  93                 (unsigned long)ZONEID_PGOFF);
  94         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_usage",
  95                 "location: %d -> %d layout %d -> %d unused %d -> %d page-flags\n",
  96                 shift, width, width, NR_PAGEFLAGS, NR_PAGEFLAGS, 0);
  97 #ifdef NODE_NOT_IN_PAGE_FLAGS
  98         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodeflags",
  99                 "Node not in page flags");
 100 #endif
 101 #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
 102         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodeflags",
 103                 "Last cpupid not in page flags");
 104 #endif
 105
 106         if (SECTIONS_WIDTH) {
 107                 shift -= SECTIONS_WIDTH;
 108                 BUG_ON(shift != SECTIONS_PGSHIFT);
 109         }
 110         if (NODES_WIDTH) {
 111                 shift -= NODES_WIDTH;
 112                 BUG_ON(shift != NODES_PGSHIFT);
 113         }
 114         if (ZONES_WIDTH) {
 115                 shift -= ZONES_WIDTH;
 116                 BUG_ON(shift != ZONES_PGSHIFT);
 117         }
 118
 119         /* Check for bitmask overlaps */
 120         or_mask = (ZONES_MASK << ZONES_PGSHIFT) |
 121                         (NODES_MASK << NODES_PGSHIFT) |
 122                         (SECTIONS_MASK << SECTIONS_PGSHIFT);
 123         add_mask = (ZONES_MASK << ZONES_PGSHIFT) +
 124                         (NODES_MASK << NODES_PGSHIFT) +
 125                         (SECTIONS_MASK << SECTIONS_PGSHIFT);
 126         BUG_ON(or_mask != add_mask);
 127 }
 128
 129 static __init int set_mminit_loglevel(char *str)
 130 {
 131         get_option(&str, &mminit_loglevel);
 132         return 0;
 133 }
 134 early_param("mminit_loglevel", set_mminit_loglevel);
 135 #endif /* CONFIG_DEBUG_MEMORY_INIT */
 136
 137 struct kobject *mm_kobj;
 138 EXPORT_SYMBOL_GPL(mm_kobj);
 139
 140 #ifdef CONFIG_SMP
 141 s32 vm_committed_as_batch = 32;
 142
 143 static void __meminit mm_compute_batch(void)
 144 {
 145         u64 memsized_batch;
 146         s32 nr = num_present_cpus();
 147         s32 batch = max_t(s32, nr*2, 32);
 148
 149         /* batch size set to 0.4% of (total memory/#cpus), or max int32 */
 150         memsized_batch = min_t(u64, (totalram_pages()/nr)/256, 0x7fffffff);
 151
 152         vm_committed_as_batch = max_t(s32, memsized_batch, batch);
 153 }
 154
 155 static int __meminit mm_compute_batch_notifier(struct notifier_block *self,
 156                                         unsigned long action, void *arg)
 157 {
 158         switch (action) {
 159         case MEM_ONLINE:
 160         case MEM_OFFLINE:
 161                 mm_compute_batch();
 162         default:
 163                 break;
 164         }
 165         return NOTIFY_OK;
 166 }
 167
 168 static struct notifier_block compute_batch_nb __meminitdata = {
 169         .notifier_call = mm_compute_batch_notifier,
 170         .priority = IPC_CALLBACK_PRI, /* use lowest priority */
 171 };
 172
 173 static int __init mm_compute_batch_init(void)
 174 {
 175         mm_compute_batch();
 176         register_hotmemory_notifier(&compute_batch_nb);
 177
 178         return 0;
 179 }
 180
 181 __initcall(mm_compute_batch_init);
 182
 183 #endif
 184
 185 static int __init mm_sysfs_init(void)
 186 {
 187         mm_kobj = kobject_create_and_add("mm", kernel_kobj);
 188         if (!mm_kobj)
 189                 return -ENOMEM;
 190
 191         return 0;
 192 }
 193 postcore_initcall(mm_sysfs_init);