root/mm/mm_init.c

DEFINITIONS

1. mminit_verify_zonelist
2. mminit_verify_pageflags_layout
3. mminit_verify_page_links
4. set_mminit_loglevel
5. mm_sysfs_init

/*
 * mm_init.c - Memory initialisation verification and debugging
 *
 * Copyright 2008 IBM Corporation, 2008
 * Author Mel Gorman <mel@csn.ul.ie>
 *
 */
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/kobject.h>
#include <linux/module.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);