mm_init.c

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/*
 * mm_init.c - Memory initialisation verification and debugging
 *
 * Copyright 2008 IBM Corporation, 2008
 * Author Mel Gorman <[email protected]>
 *
 */
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/kobject.h>
#include <linux/export.h>
#include "internal.h"

#ifdef CONFIG_DEBUG_MEMORY_INIT
int mminit_loglevel;

#ifndef SECTIONS_SHIFT
#define SECTIONS_SHIFT  0
#endif

/* The zonelists are simply reported, validation is manual. */
void mminit_verify_zonelist(void)
{
    int nid;

    if (mminit_loglevel < MMINIT_VERIFY)
        return;

    for_each_online_node(nid) {
        pg_data_t *pgdat = NODE_DATA(nid);
        struct zone *zone;
        struct zoneref *z;
        struct zonelist *zonelist;
        int i, listid, zoneid;

        BUG_ON(MAX_ZONELISTS > 2);
        for (i = 0; i < MAX_ZONELISTS * MAX_NR_ZONES; i++) {

            /* Identify the zone and nodelist */
            zoneid = i % MAX_NR_ZONES;
            listid = i / MAX_NR_ZONES;
            zonelist = &pgdat->node_zonelists[listid];
            zone = &pgdat->node_zones[zoneid];
            if (!populated_zone(zone))
                continue;

            /* Print information about the zonelist */
            printk(KERN_DEBUG "mminit::zonelist %s %d:%s = ",
                listid > 0 ? "thisnode" : "general", nid,
                zone->name);

            /* Iterate the zonelist */
            for_each_zone_zonelist(zone, z, zonelist, zoneid) {
#ifdef CONFIG_NUMA
                printk(KERN_CONT "%d:%s ",
                    zone->node, zone->name);
#else
                printk(KERN_CONT "0:%s ", zone->name);
#endif /* CONFIG_NUMA */
            }
            printk(KERN_CONT "\n");
        }
    }
}

void __init mminit_verify_pageflags_layout(void)
{
    int shift, width;
    unsigned long or_mask, add_mask;

    shift = 8 * sizeof(unsigned long);
    width = shift - SECTIONS_WIDTH - NODES_WIDTH - ZONES_WIDTH;
    mminit_dprintk(MMINIT_TRACE, "pageflags_layout_widths",
        "Section %d Node %d Zone %d Flags %d\n",
        SECTIONS_WIDTH,
        NODES_WIDTH,
        ZONES_WIDTH,
        NR_PAGEFLAGS);
    mminit_dprintk(MMINIT_TRACE, "pageflags_layout_shifts",
        "Section %d Node %d Zone %d\n",
        SECTIONS_SHIFT,
        NODES_SHIFT,
        ZONES_SHIFT);
    mminit_dprintk(MMINIT_TRACE, "pageflags_layout_offsets",
        "Section %lu Node %lu Zone %lu\n",
        (unsigned long)SECTIONS_PGSHIFT,
        (unsigned long)NODES_PGSHIFT,
        (unsigned long)ZONES_PGSHIFT);
    mminit_dprintk(MMINIT_TRACE, "pageflags_layout_zoneid",
        "Zone ID: %lu -> %lu\n",
        (unsigned long)ZONEID_PGOFF,
        (unsigned long)(ZONEID_PGOFF + ZONEID_SHIFT));
    mminit_dprintk(MMINIT_TRACE, "pageflags_layout_usage",
        "location: %d -> %d unused %d -> %d flags %d -> %d\n",
        shift, width, width, NR_PAGEFLAGS, NR_PAGEFLAGS, 0);
#ifdef NODE_NOT_IN_PAGE_FLAGS
    mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodeflags",
        "Node not in page flags");
#endif

    if (SECTIONS_WIDTH) {
        shift -= SECTIONS_WIDTH;
        BUG_ON(shift != SECTIONS_PGSHIFT);
    }
    if (NODES_WIDTH) {
        shift -= NODES_WIDTH;
        BUG_ON(shift != NODES_PGSHIFT);
    }
    if (ZONES_WIDTH) {
        shift -= ZONES_WIDTH;
        BUG_ON(shift != ZONES_PGSHIFT);
    }

    /* Check for bitmask overlaps */
    or_mask = (ZONES_MASK << ZONES_PGSHIFT) |
            (NODES_MASK << NODES_PGSHIFT) |
            (SECTIONS_MASK << SECTIONS_PGSHIFT);
    add_mask = (ZONES_MASK << ZONES_PGSHIFT) +
            (NODES_MASK << NODES_PGSHIFT) +
            (SECTIONS_MASK << SECTIONS_PGSHIFT);
    BUG_ON(or_mask != add_mask);
}

void __meminit mminit_verify_page_links(struct page *page, enum zone_type zone,
            unsigned long nid, unsigned long pfn)
{
    BUG_ON(page_to_nid(page) != nid);
    BUG_ON(page_zonenum(page) != zone);
    BUG_ON(page_to_pfn(page) != pfn);
}

static __init int set_mminit_loglevel(char *str)
{
    get_option(&str, &mminit_loglevel);
    return 0;
}
early_param("mminit_loglevel", set_mminit_loglevel);
#endif /* CONFIG_DEBUG_MEMORY_INIT */

struct kobject *mm_kobj;
EXPORT_SYMBOL_GPL(mm_kobj);

static int __init mm_sysfs_init(void)
{
    mm_kobj = kobject_create_and_add("mm", kernel_kobj);
    if (!mm_kobj)
        return -ENOMEM;

    return 0;
}

__initcall(mm_sysfs_init);