linux/mm/mm_init.c
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   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
  19int __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. */
  26void __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                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
  64void __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
 129static __init int set_mminit_loglevel(char *str)
 130{
 131        get_option(&str, &mminit_loglevel);
 132        return 0;
 133}
 134early_param("mminit_loglevel", set_mminit_loglevel);
 135#endif /* CONFIG_DEBUG_MEMORY_INIT */
 136
 137struct kobject *mm_kobj;
 138EXPORT_SYMBOL_GPL(mm_kobj);
 139
 140#ifdef CONFIG_SMP
 141s32 vm_committed_as_batch = 32;
 142
 143static 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
 155static 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
 168static struct notifier_block compute_batch_nb __meminitdata = {
 169        .notifier_call = mm_compute_batch_notifier,
 170        .priority = IPC_CALLBACK_PRI, /* use lowest priority */
 171};
 172
 173static 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
 185static 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}
 193postcore_initcall(mm_sysfs_init);
 194