Root/mm/mm_init.c

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/module.h>
12#include "internal.h"
13
14#ifdef CONFIG_DEBUG_MEMORY_INIT
15int mminit_loglevel;
16
17#ifndef SECTIONS_SHIFT
18#define SECTIONS_SHIFT 0
19#endif
20
21/* The zonelists are simply reported, validation is manual. */
22void mminit_verify_zonelist(void)
23{
24    int nid;
25
26    if (mminit_loglevel < MMINIT_VERIFY)
27        return;
28
29    for_each_online_node(nid) {
30        pg_data_t *pgdat = NODE_DATA(nid);
31        struct zone *zone;
32        struct zoneref *z;
33        struct zonelist *zonelist;
34        int i, listid, zoneid;
35
36        BUG_ON(MAX_ZONELISTS > 2);
37        for (i = 0; i < MAX_ZONELISTS * MAX_NR_ZONES; i++) {
38
39            /* Identify the zone and nodelist */
40            zoneid = i % MAX_NR_ZONES;
41            listid = i / MAX_NR_ZONES;
42            zonelist = &pgdat->node_zonelists[listid];
43            zone = &pgdat->node_zones[zoneid];
44            if (!populated_zone(zone))
45                continue;
46
47            /* Print information about the zonelist */
48            printk(KERN_DEBUG "mminit::zonelist %s %d:%s = ",
49                listid > 0 ? "thisnode" : "general", nid,
50                zone->name);
51
52            /* Iterate the zonelist */
53            for_each_zone_zonelist(zone, z, zonelist, zoneid) {
54#ifdef CONFIG_NUMA
55                printk(KERN_CONT "%d:%s ",
56                    zone->node, zone->name);
57#else
58                printk(KERN_CONT "0:%s ", zone->name);
59#endif /* CONFIG_NUMA */
60            }
61            printk(KERN_CONT "\n");
62        }
63    }
64}
65
66void __init mminit_verify_pageflags_layout(void)
67{
68    int shift, width;
69    unsigned long or_mask, add_mask;
70
71    shift = 8 * sizeof(unsigned long);
72    width = shift - SECTIONS_WIDTH - NODES_WIDTH - ZONES_WIDTH;
73    mminit_dprintk(MMINIT_TRACE, "pageflags_layout_widths",
74        "Section %d Node %d Zone %d Flags %d\n",
75        SECTIONS_WIDTH,
76        NODES_WIDTH,
77        ZONES_WIDTH,
78        NR_PAGEFLAGS);
79    mminit_dprintk(MMINIT_TRACE, "pageflags_layout_shifts",
80        "Section %d Node %d Zone %d\n",
81        SECTIONS_SHIFT,
82        NODES_SHIFT,
83        ZONES_SHIFT);
84    mminit_dprintk(MMINIT_TRACE, "pageflags_layout_offsets",
85        "Section %lu Node %lu Zone %lu\n",
86        (unsigned long)SECTIONS_PGSHIFT,
87        (unsigned long)NODES_PGSHIFT,
88        (unsigned long)ZONES_PGSHIFT);
89    mminit_dprintk(MMINIT_TRACE, "pageflags_layout_zoneid",
90        "Zone ID: %lu -> %lu\n",
91        (unsigned long)ZONEID_PGOFF,
92        (unsigned long)(ZONEID_PGOFF + ZONEID_SHIFT));
93    mminit_dprintk(MMINIT_TRACE, "pageflags_layout_usage",
94        "location: %d -> %d unused %d -> %d flags %d -> %d\n",
95        shift, width, width, NR_PAGEFLAGS, NR_PAGEFLAGS, 0);
96#ifdef NODE_NOT_IN_PAGE_FLAGS
97    mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodeflags",
98        "Node not in page flags");
99#endif
100
101    if (SECTIONS_WIDTH) {
102        shift -= SECTIONS_WIDTH;
103        BUG_ON(shift != SECTIONS_PGSHIFT);
104    }
105    if (NODES_WIDTH) {
106        shift -= NODES_WIDTH;
107        BUG_ON(shift != NODES_PGSHIFT);
108    }
109    if (ZONES_WIDTH) {
110        shift -= ZONES_WIDTH;
111        BUG_ON(shift != ZONES_PGSHIFT);
112    }
113
114    /* Check for bitmask overlaps */
115    or_mask = (ZONES_MASK << ZONES_PGSHIFT) |
116            (NODES_MASK << NODES_PGSHIFT) |
117            (SECTIONS_MASK << SECTIONS_PGSHIFT);
118    add_mask = (ZONES_MASK << ZONES_PGSHIFT) +
119            (NODES_MASK << NODES_PGSHIFT) +
120            (SECTIONS_MASK << SECTIONS_PGSHIFT);
121    BUG_ON(or_mask != add_mask);
122}
123
124void __meminit mminit_verify_page_links(struct page *page, enum zone_type zone,
125            unsigned long nid, unsigned long pfn)
126{
127    BUG_ON(page_to_nid(page) != nid);
128    BUG_ON(page_zonenum(page) != zone);
129    BUG_ON(page_to_pfn(page) != pfn);
130}
131
132static __init int set_mminit_loglevel(char *str)
133{
134    get_option(&str, &mminit_loglevel);
135    return 0;
136}
137early_param("mminit_loglevel", set_mminit_loglevel);
138#endif /* CONFIG_DEBUG_MEMORY_INIT */
139
140struct kobject *mm_kobj;
141EXPORT_SYMBOL_GPL(mm_kobj);
142
143static int __init mm_sysfs_init(void)
144{
145    mm_kobj = kobject_create_and_add("mm", kernel_kobj);
146    if (!mm_kobj)
147        return -ENOMEM;
148
149    return 0;
150}
151
152__initcall(mm_sysfs_init);
153

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