Linux Kernel  3.7.1
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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 <[email protected]>
6  *
7  */
8 #include <linux/kernel.h>
9 #include <linux/init.h>
10 #include <linux/kobject.h>
11 #include <linux/export.h>
12 #include "internal.h"
13 
14 #ifdef CONFIG_DEBUG_MEMORY_INIT
15 int mminit_loglevel;
16 
17 #ifndef SECTIONS_SHIFT
18 #define SECTIONS_SHIFT 0
19 #endif
20 
21 /* The zonelists are simply reported, validation is manual. */
22 void mminit_verify_zonelist(void)
23 {
24  int nid;
25 
26  if (mminit_loglevel < MMINIT_VERIFY)
27  return;
28 
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 
66 void __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,
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 
124 void __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 
132 static __init int set_mminit_loglevel(char *str)
133 {
134  get_option(&str, &mminit_loglevel);
135  return 0;
136 }
137 early_param("mminit_loglevel", set_mminit_loglevel);
138 #endif /* CONFIG_DEBUG_MEMORY_INIT */
139 
140 struct kobject *mm_kobj;
141 EXPORT_SYMBOL_GPL(mm_kobj);
142 
143 static 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);