LXR linux/mm/mm

   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
  20int __meminitdata mminit_loglevel;
  21
  22#ifndef SECTIONS_SHIFT
  23#define SECTIONS_SHIFT  0
  24#endif
  25
  26/* The zonelists are simply reported, validation is manual. */
  27void __init mminit_verify_zonelist(void)
  28{
  29        int nid;
  30
  31        if (mminit_loglevel < MMINIT_VERIFY)
  32                return;
  33
  34        for_each_online_node(nid) {
  35                pg_data_t *pgdat = NODE_DATA(nid);
  36                struct zone *zone;
  37                struct zoneref *z;
  38                struct zonelist *zonelist;
  39                int i, listid, zoneid;
  40
  41                BUILD_BUG_ON(MAX_ZONELISTS > 2);
  42                for (i = 0; i < MAX_ZONELISTS * MAX_NR_ZONES; i++) {
  43
  44                        /* Identify the zone and nodelist */
  45                        zoneid = i % MAX_NR_ZONES;
  46                        listid = i / MAX_NR_ZONES;
  47                        zonelist = &pgdat->node_zonelists[listid];
  48                        zone = &pgdat->node_zones[zoneid];
  49                        if (!populated_zone(zone))
  50                                continue;
  51
  52                        /* Print information about the zonelist */
  53                        printk(KERN_DEBUG "mminit::zonelist %s %d:%s = ",
  54                                listid > 0 ? "thisnode" : "general", nid,
  55                                zone->name);
  56
  57                        /* Iterate the zonelist */
  58                        for_each_zone_zonelist(zone, z, zonelist, zoneid)
  59                                pr_cont("%d:%s ", zone_to_nid(zone), zone->name);
  60                        pr_cont("\n");
  61                }
  62        }
  63}
  64
  65void __init mminit_verify_pageflags_layout(void)
  66{
  67        int shift, width;
  68        unsigned long or_mask, add_mask;
  69
  70        shift = 8 * sizeof(unsigned long);
  71        width = shift - SECTIONS_WIDTH - NODES_WIDTH - ZONES_WIDTH
  72                - LAST_CPUPID_SHIFT - KASAN_TAG_WIDTH;
  73        mminit_dprintk(MMINIT_TRACE, "pageflags_layout_widths",
  74                "Section %d Node %d Zone %d Lastcpupid %d Kasantag %d Flags %d\n",
  75                SECTIONS_WIDTH,
  76                NODES_WIDTH,
  77                ZONES_WIDTH,
  78                LAST_CPUPID_WIDTH,
  79                KASAN_TAG_WIDTH,
  80                NR_PAGEFLAGS);
  81        mminit_dprintk(MMINIT_TRACE, "pageflags_layout_shifts",
  82                "Section %d Node %d Zone %d Lastcpupid %d Kasantag %d\n",
  83                SECTIONS_SHIFT,
  84                NODES_SHIFT,
  85                ZONES_SHIFT,
  86                LAST_CPUPID_SHIFT,
  87                KASAN_TAG_WIDTH);
  88        mminit_dprintk(MMINIT_TRACE, "pageflags_layout_pgshifts",
  89                "Section %lu Node %lu Zone %lu Lastcpupid %lu Kasantag %lu\n",
  90                (unsigned long)SECTIONS_PGSHIFT,
  91                (unsigned long)NODES_PGSHIFT,
  92                (unsigned long)ZONES_PGSHIFT,
  93                (unsigned long)LAST_CPUPID_PGSHIFT,
  94                (unsigned long)KASAN_TAG_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
 134static __init int set_mminit_loglevel(char *str)
 135{
 136        get_option(&str, &mminit_loglevel);
 137        return 0;
 138}
 139early_param("mminit_loglevel", set_mminit_loglevel);
 140#endif /* CONFIG_DEBUG_MEMORY_INIT */
 141
 142struct kobject *mm_kobj;
 143EXPORT_SYMBOL_GPL(mm_kobj);
 144
 145#ifdef CONFIG_SMP
 146s32 vm_committed_as_batch = 32;
 147
 148void mm_compute_batch(int overcommit_policy)
 149{
 150        u64 memsized_batch;
 151        s32 nr = num_present_cpus();
 152        s32 batch = max_t(s32, nr*2, 32);
 153        unsigned long ram_pages = totalram_pages();
 154
 155        /*
 156         * For policy OVERCOMMIT_NEVER, set batch size to 0.4% of
 157         * (total memory/#cpus), and lift it to 25% for other policies
 158         * to easy the possible lock contention for percpu_counter
 159         * vm_committed_as, while the max limit is INT_MAX
 160         */
 161        if (overcommit_policy == OVERCOMMIT_NEVER)
 162                memsized_batch = min_t(u64, ram_pages/nr/256, INT_MAX);
 163        else
 164                memsized_batch = min_t(u64, ram_pages/nr/4, INT_MAX);
 165
 166        vm_committed_as_batch = max_t(s32, memsized_batch, batch);
 167}
 168
 169static int __meminit mm_compute_batch_notifier(struct notifier_block *self,
 170                                        unsigned long action, void *arg)
 171{
 172        switch (action) {
 173        case MEM_ONLINE:
 174        case MEM_OFFLINE:
 175                mm_compute_batch(sysctl_overcommit_memory);
 176        default:
 177                break;
 178        }
 179        return NOTIFY_OK;
 180}
 181
 182static struct notifier_block compute_batch_nb __meminitdata = {
 183        .notifier_call = mm_compute_batch_notifier,
 184        .priority = IPC_CALLBACK_PRI, /* use lowest priority */
 185};
 186
 187static int __init mm_compute_batch_init(void)
 188{
 189        mm_compute_batch(sysctl_overcommit_memory);
 190        register_hotmemory_notifier(&compute_batch_nb);
 191
 192        return 0;
 193}
 194
 195__initcall(mm_compute_batch_init);
 196
 197#endif
 198
 199static int __init mm_sysfs_init(void)
 200{
 201        mm_kobj = kobject_create_and_add("mm", kernel_kobj);
 202        if (!mm_kobj)
 203                return -ENOMEM;
 204
 205        return 0;
 206}
 207postcore_initcall(mm_sysfs_init);
 208