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/* The zonelists are simply reported, validation is manual. */
  23void __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
  61void __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
 130static __init int set_mminit_loglevel(char *str)
 131{
 132        get_option(&str, &mminit_loglevel);
 133        return 0;
 134}
 135early_param("mminit_loglevel", set_mminit_loglevel);
 136#endif /* CONFIG_DEBUG_MEMORY_INIT */
 137
 138struct kobject *mm_kobj;
 139EXPORT_SYMBOL_GPL(mm_kobj);
 140
 141#ifdef CONFIG_SMP
 142s32 vm_committed_as_batch = 32;
 143
 144void 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
 165static 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
 179static struct notifier_block compute_batch_nb __meminitdata = {
 180        .notifier_call = mm_compute_batch_notifier,
 181        .priority = IPC_CALLBACK_PRI, /* use lowest priority */
 182};
 183
 184static 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
 196static 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}
 204postcore_initcall(mm_sysfs_init);
 205