linux/mm/mm_init.c
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   1/*
   2 * mm_init.c - Memory initialisation verification and debugging
   3 *
   4 * Copyright 2008 IBM Corporation, 2008
   5 * Author Mel Gorman <mel@csn.ul.ie>
   6 *
   7 */
   8#include <linux/kernel.h>
   9#include <linux/init.h>
  10#include <linux/kobject.h>
  11#include <linux/export.h>
  12#include <linux/memory.h>
  13#include <linux/notifier.h>
  14#include <linux/sched.h>
  15#include "internal.h"
  16
  17#ifdef CONFIG_DEBUG_MEMORY_INIT
  18int __meminitdata mminit_loglevel;
  19
  20#ifndef SECTIONS_SHIFT
  21#define SECTIONS_SHIFT  0
  22#endif
  23
  24/* The zonelists are simply reported, validation is manual. */
  25void __init mminit_verify_zonelist(void)
  26{
  27        int nid;
  28
  29        if (mminit_loglevel < MMINIT_VERIFY)
  30                return;
  31
  32        for_each_online_node(nid) {
  33                pg_data_t *pgdat = NODE_DATA(nid);
  34                struct zone *zone;
  35                struct zoneref *z;
  36                struct zonelist *zonelist;
  37                int i, listid, zoneid;
  38
  39                BUG_ON(MAX_ZONELISTS > 2);
  40                for (i = 0; i < MAX_ZONELISTS * MAX_NR_ZONES; i++) {
  41
  42                        /* Identify the zone and nodelist */
  43                        zoneid = i % MAX_NR_ZONES;
  44                        listid = i / MAX_NR_ZONES;
  45                        zonelist = &pgdat->node_zonelists[listid];
  46                        zone = &pgdat->node_zones[zoneid];
  47                        if (!populated_zone(zone))
  48                                continue;
  49
  50                        /* Print information about the zonelist */
  51                        printk(KERN_DEBUG "mminit::zonelist %s %d:%s = ",
  52                                listid > 0 ? "thisnode" : "general", nid,
  53                                zone->name);
  54
  55                        /* Iterate the zonelist */
  56                        for_each_zone_zonelist(zone, z, zonelist, zoneid) {
  57#ifdef CONFIG_NUMA
  58                                pr_cont("%d:%s ", zone->node, zone->name);
  59#else
  60                                pr_cont("0:%s ", zone->name);
  61#endif /* CONFIG_NUMA */
  62                        }
  63                        pr_cont("\n");
  64                }
  65        }
  66}
  67
  68void __init mminit_verify_pageflags_layout(void)
  69{
  70        int shift, width;
  71        unsigned long or_mask, add_mask;
  72
  73        shift = 8 * sizeof(unsigned long);
  74        width = shift - SECTIONS_WIDTH - NODES_WIDTH - ZONES_WIDTH - LAST_CPUPID_SHIFT;
  75        mminit_dprintk(MMINIT_TRACE, "pageflags_layout_widths",
  76                "Section %d Node %d Zone %d Lastcpupid %d Flags %d\n",
  77                SECTIONS_WIDTH,
  78                NODES_WIDTH,
  79                ZONES_WIDTH,
  80                LAST_CPUPID_WIDTH,
  81                NR_PAGEFLAGS);
  82        mminit_dprintk(MMINIT_TRACE, "pageflags_layout_shifts",
  83                "Section %d Node %d Zone %d Lastcpupid %d\n",
  84                SECTIONS_SHIFT,
  85                NODES_SHIFT,
  86                ZONES_SHIFT,
  87                LAST_CPUPID_SHIFT);
  88        mminit_dprintk(MMINIT_TRACE, "pageflags_layout_pgshifts",
  89                "Section %lu Node %lu Zone %lu Lastcpupid %lu\n",
  90                (unsigned long)SECTIONS_PGSHIFT,
  91                (unsigned long)NODES_PGSHIFT,
  92                (unsigned long)ZONES_PGSHIFT,
  93                (unsigned long)LAST_CPUPID_PGSHIFT);
  94        mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodezoneid",
  95                "Node/Zone ID: %lu -> %lu\n",
  96                (unsigned long)(ZONEID_PGOFF + ZONEID_SHIFT),
  97                (unsigned long)ZONEID_PGOFF);
  98        mminit_dprintk(MMINIT_TRACE, "pageflags_layout_usage",
  99                "location: %d -> %d layout %d -> %d unused %d -> %d page-flags\n",
 100                shift, width, width, NR_PAGEFLAGS, NR_PAGEFLAGS, 0);
 101#ifdef NODE_NOT_IN_PAGE_FLAGS
 102        mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodeflags",
 103                "Node not in page flags");
 104#endif
 105#ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
 106        mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodeflags",
 107                "Last cpupid not in page flags");
 108#endif
 109
 110        if (SECTIONS_WIDTH) {
 111                shift -= SECTIONS_WIDTH;
 112                BUG_ON(shift != SECTIONS_PGSHIFT);
 113        }
 114        if (NODES_WIDTH) {
 115                shift -= NODES_WIDTH;
 116                BUG_ON(shift != NODES_PGSHIFT);
 117        }
 118        if (ZONES_WIDTH) {
 119                shift -= ZONES_WIDTH;
 120                BUG_ON(shift != ZONES_PGSHIFT);
 121        }
 122
 123        /* Check for bitmask overlaps */
 124        or_mask = (ZONES_MASK << ZONES_PGSHIFT) |
 125                        (NODES_MASK << NODES_PGSHIFT) |
 126                        (SECTIONS_MASK << SECTIONS_PGSHIFT);
 127        add_mask = (ZONES_MASK << ZONES_PGSHIFT) +
 128                        (NODES_MASK << NODES_PGSHIFT) +
 129                        (SECTIONS_MASK << SECTIONS_PGSHIFT);
 130        BUG_ON(or_mask != add_mask);
 131}
 132
 133static __init int set_mminit_loglevel(char *str)
 134{
 135        get_option(&str, &mminit_loglevel);
 136        return 0;
 137}
 138early_param("mminit_loglevel", set_mminit_loglevel);
 139#endif /* CONFIG_DEBUG_MEMORY_INIT */
 140
 141struct kobject *mm_kobj;
 142EXPORT_SYMBOL_GPL(mm_kobj);
 143
 144#ifdef CONFIG_SMP
 145s32 vm_committed_as_batch = 32;
 146
 147static void __meminit mm_compute_batch(void)
 148{
 149        u64 memsized_batch;
 150        s32 nr = num_present_cpus();
 151        s32 batch = max_t(s32, nr*2, 32);
 152
 153        /* batch size set to 0.4% of (total memory/#cpus), or max int32 */
 154        memsized_batch = min_t(u64, (totalram_pages/nr)/256, 0x7fffffff);
 155
 156        vm_committed_as_batch = max_t(s32, memsized_batch, batch);
 157}
 158
 159static int __meminit mm_compute_batch_notifier(struct notifier_block *self,
 160                                        unsigned long action, void *arg)
 161{
 162        switch (action) {
 163        case MEM_ONLINE:
 164        case MEM_OFFLINE:
 165                mm_compute_batch();
 166        default:
 167                break;
 168        }
 169        return NOTIFY_OK;
 170}
 171
 172static struct notifier_block compute_batch_nb __meminitdata = {
 173        .notifier_call = mm_compute_batch_notifier,
 174        .priority = IPC_CALLBACK_PRI, /* use lowest priority */
 175};
 176
 177static int __init mm_compute_batch_init(void)
 178{
 179        mm_compute_batch();
 180        register_hotmemory_notifier(&compute_batch_nb);
 181
 182        return 0;
 183}
 184
 185__initcall(mm_compute_batch_init);
 186
 187#endif
 188
 189static int __init mm_sysfs_init(void)
 190{
 191        mm_kobj = kobject_create_and_add("mm", kernel_kobj);
 192        if (!mm_kobj)
 193                return -ENOMEM;
 194
 195        return 0;
 196}
 197postcore_initcall(mm_sysfs_init);
 198