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 <linux/mman.h>
  17 #include "internal.h"
  18
  19 #ifdef CONFIG_DEBUG_MEMORY_INIT
  20 int __meminitdata mminit_loglevel;
  21
  22 /* The zonelists are simply reported, validation is manual. */
  23 void __init mminit_verify_zonelist(void)
  24 {
  25         int nid;
  26
  27         if (mminit_loglevel < MMINIT_VERIFY)
  28                 return;
  29
  30         for_each_online_node(nid) {
  31                 pg_data_t *pgdat = NODE_DATA(nid);
  32                 struct zone *zone;
  33                 struct zoneref *z;
  34                 struct zonelist *zonelist;
  35                 int i, listid, zoneid;
  36
  37                 BUILD_BUG_ON(MAX_ZONELISTS > 2);
  38                 for (i = 0; i < MAX_ZONELISTS * MAX_NR_ZONES; i++) {
  39
  40                         /* Identify the zone and nodelist */
  41                         zoneid = i % MAX_NR_ZONES;
  42                         listid = i / MAX_NR_ZONES;
  43                         zonelist = &pgdat->node_zonelists[listid];
  44                         zone = &pgdat->node_zones[zoneid];
  45                         if (!populated_zone(zone))
  46                                 continue;
  47
  48                         /* Print information about the zonelist */
  49                         printk(KERN_DEBUG "mminit::zonelist %s %d:%s = ",
  50                                 listid > 0 ? "thisnode" : "general", nid,
  51                                 zone->name);
  52
  53                         /* Iterate the zonelist */
  54                         for_each_zone_zonelist(zone, z, zonelist, zoneid)
  55                                 pr_cont("%d:%s ", zone_to_nid(zone), zone->name);
  56                         pr_cont("\n");
  57                 }
  58         }
  59 }
  60
  61 void __init mminit_verify_pageflags_layout(void)
  62 {
  63         int shift, width;
  64         unsigned long or_mask, add_mask;
  65
  66         shift = 8 * sizeof(unsigned long);
  67         width = shift - SECTIONS_WIDTH - NODES_WIDTH - ZONES_WIDTH
  68                 - LAST_CPUPID_SHIFT - KASAN_TAG_WIDTH;
  69         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_widths",
  70                 "Section %d Node %d Zone %d Lastcpupid %d Kasantag %d Flags %d\n",
  71                 SECTIONS_WIDTH,
  72                 NODES_WIDTH,
  73                 ZONES_WIDTH,
  74                 LAST_CPUPID_WIDTH,
  75                 KASAN_TAG_WIDTH,
  76                 NR_PAGEFLAGS);
  77         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_shifts",
  78                 "Section %d Node %d Zone %d Lastcpupid %d Kasantag %d\n",
  79                 SECTIONS_SHIFT,
  80                 NODES_SHIFT,
  81                 ZONES_SHIFT,
  82                 LAST_CPUPID_SHIFT,
  83                 KASAN_TAG_WIDTH);
  84         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_pgshifts",
  85                 "Section %lu Node %lu Zone %lu Lastcpupid %lu Kasantag %lu\n",
  86                 (unsigned long)SECTIONS_PGSHIFT,
  87                 (unsigned long)NODES_PGSHIFT,
  88                 (unsigned long)ZONES_PGSHIFT,
  89                 (unsigned long)LAST_CPUPID_PGSHIFT,
  90                 (unsigned long)KASAN_TAG_PGSHIFT);
  91         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodezoneid",
  92                 "Node/Zone ID: %lu -> %lu\n",
  93                 (unsigned long)(ZONEID_PGOFF + ZONEID_SHIFT),
  94                 (unsigned long)ZONEID_PGOFF);
  95         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_usage",
  96                 "location: %d -> %d layout %d -> %d unused %d -> %d page-flags\n",
  97                 shift, width, width, NR_PAGEFLAGS, NR_PAGEFLAGS, 0);
  98 #ifdef NODE_NOT_IN_PAGE_FLAGS
  99         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodeflags",
 100                 "Node not in page flags");
 101 #endif
 102 #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
 103         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodeflags",
 104                 "Last cpupid not in page flags");
 105 #endif
 106
 107         if (SECTIONS_WIDTH) {
 108                 shift -= SECTIONS_WIDTH;
 109                 BUG_ON(shift != SECTIONS_PGSHIFT);
 110         }
 111         if (NODES_WIDTH) {
 112                 shift -= NODES_WIDTH;
 113                 BUG_ON(shift != NODES_PGSHIFT);
 114         }
 115         if (ZONES_WIDTH) {
 116                 shift -= ZONES_WIDTH;
 117                 BUG_ON(shift != ZONES_PGSHIFT);
 118         }
 119
 120         /* Check for bitmask overlaps */
 121         or_mask = (ZONES_MASK << ZONES_PGSHIFT) |
 122                         (NODES_MASK << NODES_PGSHIFT) |
 123                         (SECTIONS_MASK << SECTIONS_PGSHIFT);
 124         add_mask = (ZONES_MASK << ZONES_PGSHIFT) +
 125                         (NODES_MASK << NODES_PGSHIFT) +
 126                         (SECTIONS_MASK << SECTIONS_PGSHIFT);
 127         BUG_ON(or_mask != add_mask);
 128 }
 129
 130 static __init int set_mminit_loglevel(char *str)
 131 {
 132         get_option(&str, &mminit_loglevel);
 133         return 0;
 134 }
 135 early_param("mminit_loglevel", set_mminit_loglevel);
 136 #endif /* CONFIG_DEBUG_MEMORY_INIT */
 137
 138 struct kobject *mm_kobj;
 139 EXPORT_SYMBOL_GPL(mm_kobj);
 140
 141 #ifdef CONFIG_SMP
 142 s32 vm_committed_as_batch = 32;
 143
 144 void mm_compute_batch(int overcommit_policy)
 145 {
 146         u64 memsized_batch;
 147         s32 nr = num_present_cpus();
 148         s32 batch = max_t(s32, nr*2, 32);
 149         unsigned long ram_pages = totalram_pages();
 150
 151         /*
 152          * For policy OVERCOMMIT_NEVER, set batch size to 0.4% of
 153          * (total memory/#cpus), and lift it to 25% for other policies
 154          * to easy the possible lock contention for percpu_counter
 155          * vm_committed_as, while the max limit is INT_MAX
 156          */
 157         if (overcommit_policy == OVERCOMMIT_NEVER)
 158                 memsized_batch = min_t(u64, ram_pages/nr/256, INT_MAX);
 159         else
 160                 memsized_batch = min_t(u64, ram_pages/nr/4, INT_MAX);
 161
 162         vm_committed_as_batch = max_t(s32, memsized_batch, batch);
 163 }
 164
 165 static int __meminit mm_compute_batch_notifier(struct notifier_block *self,
 166                                         unsigned long action, void *arg)
 167 {
 168         switch (action) {
 169         case MEM_ONLINE:
 170         case MEM_OFFLINE:
 171                 mm_compute_batch(sysctl_overcommit_memory);
 172                 break;
 173         default:
 174                 break;
 175         }
 176         return NOTIFY_OK;
 177 }
 178
 179 static struct notifier_block compute_batch_nb __meminitdata = {
 180         .notifier_call = mm_compute_batch_notifier,
 181         .priority = IPC_CALLBACK_PRI, /* use lowest priority */
 182 };
 183
 184 static int __init mm_compute_batch_init(void)
 185 {
 186         mm_compute_batch(sysctl_overcommit_memory);
 187         register_hotmemory_notifier(&compute_batch_nb);
 188
 189         return 0;
 190 }
 191
 192 __initcall(mm_compute_batch_init);
 193
 194 #endif
 195
 196 static int __init mm_sysfs_init(void)
 197 {
 198         mm_kobj = kobject_create_and_add("mm", kernel_kobj);
 199         if (!mm_kobj)
 200                 return -ENOMEM;
 201
 202         return 0;
 203 }
 204 postcore_initcall(mm_sysfs_init);