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 "internal.h"
  15
  16#ifdef CONFIG_DEBUG_MEMORY_INIT
  17int mminit_loglevel;
  18
  19#ifndef SECTIONS_SHIFT
  20#define SECTIONS_SHIFT  0
  21#endif
  22
  23/* The zonelists are simply reported, validation is manual. */
  24void mminit_verify_zonelist(void)
  25{
  26        int nid;
  27
  28        if (mminit_loglevel < MMINIT_VERIFY)
  29                return;
  30
  31        for_each_online_node(nid) {
  32                pg_data_t *pgdat = NODE_DATA(nid);
  33                struct zone *zone;
  34                struct zoneref *z;
  35                struct zonelist *zonelist;
  36                int i, listid, zoneid;
  37
  38                BUG_ON(MAX_ZONELISTS > 2);
  39                for (i = 0; i < MAX_ZONELISTS * MAX_NR_ZONES; i++) {
  40
  41                        /* Identify the zone and nodelist */
  42                        zoneid = i % MAX_NR_ZONES;
  43                        listid = i / MAX_NR_ZONES;
  44                        zonelist = &pgdat->node_zonelists[listid];
  45                        zone = &pgdat->node_zones[zoneid];
  46                        if (!populated_zone(zone))
  47                                continue;
  48
  49                        /* Print information about the zonelist */
  50                        printk(KERN_DEBUG "mminit::zonelist %s %d:%s = ",
  51                                listid > 0 ? "thisnode" : "general", nid,
  52                                zone->name);
  53
  54                        /* Iterate the zonelist */
  55                        for_each_zone_zonelist(zone, z, zonelist, zoneid) {
  56#ifdef CONFIG_NUMA
  57                                printk(KERN_CONT "%d:%s ",
  58                                        zone->node, zone->name);
  59#else
  60                                printk(KERN_CONT "0:%s ", zone->name);
  61#endif /* CONFIG_NUMA */
  62                        }
  63                        printk(KERN_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
 133void __meminit mminit_verify_page_links(struct page *page, enum zone_type zone,
 134                        unsigned long nid, unsigned long pfn)
 135{
 136        BUG_ON(page_to_nid(page) != nid);
 137        BUG_ON(page_zonenum(page) != zone);
 138        BUG_ON(page_to_pfn(page) != pfn);
 139}
 140
 141static __init int set_mminit_loglevel(char *str)
 142{
 143        get_option(&str, &mminit_loglevel);
 144        return 0;
 145}
 146early_param("mminit_loglevel", set_mminit_loglevel);
 147#endif /* CONFIG_DEBUG_MEMORY_INIT */
 148
 149struct kobject *mm_kobj;
 150EXPORT_SYMBOL_GPL(mm_kobj);
 151
 152#ifdef CONFIG_SMP
 153s32 vm_committed_as_batch = 32;
 154
 155static void __meminit mm_compute_batch(void)
 156{
 157        u64 memsized_batch;
 158        s32 nr = num_present_cpus();
 159        s32 batch = max_t(s32, nr*2, 32);
 160
 161        /* batch size set to 0.4% of (total memory/#cpus), or max int32 */
 162        memsized_batch = min_t(u64, (totalram_pages/nr)/256, 0x7fffffff);
 163
 164        vm_committed_as_batch = max_t(s32, memsized_batch, batch);
 165}
 166
 167static int __meminit mm_compute_batch_notifier(struct notifier_block *self,
 168                                        unsigned long action, void *arg)
 169{
 170        switch (action) {
 171        case MEM_ONLINE:
 172        case MEM_OFFLINE:
 173                mm_compute_batch();
 174        default:
 175                break;
 176        }
 177        return NOTIFY_OK;
 178}
 179
 180static struct notifier_block compute_batch_nb __meminitdata = {
 181        .notifier_call = mm_compute_batch_notifier,
 182        .priority = IPC_CALLBACK_PRI, /* use lowest priority */
 183};
 184
 185static int __init mm_compute_batch_init(void)
 186{
 187        mm_compute_batch();
 188        register_hotmemory_notifier(&compute_batch_nb);
 189
 190        return 0;
 191}
 192
 193__initcall(mm_compute_batch_init);
 194
 195#endif
 196
 197static int __init mm_sysfs_init(void)
 198{
 199        mm_kobj = kobject_create_and_add("mm", kernel_kobj);
 200        if (!mm_kobj)
 201                return -ENOMEM;
 202
 203        return 0;
 204}
 205postcore_initcall(mm_sysfs_init);
 206