xref: /openbmc/linux/mm/mm_init.c (revision 0c874100)
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 <linux/sched.h>
15 #include "internal.h"
16 
17 #ifdef CONFIG_DEBUG_MEMORY_INIT
18 int __meminitdata mminit_loglevel;
19 
20 #ifndef SECTIONS_SHIFT
21 #define SECTIONS_SHIFT	0
22 #endif
23 
24 /* The zonelists are simply reported, validation is manual. */
25 void __init mminit_verify_zonelist(void)
26 {
27 	int nid;
28 
29 	if (mminit_loglevel < MMINIT_VERIFY)
30 		return;
31 
32 	for_each_online_node(nid) {
33 		pg_data_t *pgdat = NODE_DATA(nid);
34 		struct zone *zone;
35 		struct zoneref *z;
36 		struct zonelist *zonelist;
37 		int i, listid, zoneid;
38 
39 		BUG_ON(MAX_ZONELISTS > 2);
40 		for (i = 0; i < MAX_ZONELISTS * MAX_NR_ZONES; i++) {
41 
42 			/* Identify the zone and nodelist */
43 			zoneid = i % MAX_NR_ZONES;
44 			listid = i / MAX_NR_ZONES;
45 			zonelist = &pgdat->node_zonelists[listid];
46 			zone = &pgdat->node_zones[zoneid];
47 			if (!populated_zone(zone))
48 				continue;
49 
50 			/* Print information about the zonelist */
51 			printk(KERN_DEBUG "mminit::zonelist %s %d:%s = ",
52 				listid > 0 ? "thisnode" : "general", nid,
53 				zone->name);
54 
55 			/* Iterate the zonelist */
56 			for_each_zone_zonelist(zone, z, zonelist, zoneid)
57 				pr_cont("%d:%s ", zone_to_nid(zone), zone->name);
58 			pr_cont("\n");
59 		}
60 	}
61 }
62 
63 void __init mminit_verify_pageflags_layout(void)
64 {
65 	int shift, width;
66 	unsigned long or_mask, add_mask;
67 
68 	shift = 8 * sizeof(unsigned long);
69 	width = shift - SECTIONS_WIDTH - NODES_WIDTH - ZONES_WIDTH - LAST_CPUPID_SHIFT;
70 	mminit_dprintk(MMINIT_TRACE, "pageflags_layout_widths",
71 		"Section %d Node %d Zone %d Lastcpupid %d Flags %d\n",
72 		SECTIONS_WIDTH,
73 		NODES_WIDTH,
74 		ZONES_WIDTH,
75 		LAST_CPUPID_WIDTH,
76 		NR_PAGEFLAGS);
77 	mminit_dprintk(MMINIT_TRACE, "pageflags_layout_shifts",
78 		"Section %d Node %d Zone %d Lastcpupid %d\n",
79 		SECTIONS_SHIFT,
80 		NODES_SHIFT,
81 		ZONES_SHIFT,
82 		LAST_CPUPID_SHIFT);
83 	mminit_dprintk(MMINIT_TRACE, "pageflags_layout_pgshifts",
84 		"Section %lu Node %lu Zone %lu Lastcpupid %lu\n",
85 		(unsigned long)SECTIONS_PGSHIFT,
86 		(unsigned long)NODES_PGSHIFT,
87 		(unsigned long)ZONES_PGSHIFT,
88 		(unsigned long)LAST_CPUPID_PGSHIFT);
89 	mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodezoneid",
90 		"Node/Zone ID: %lu -> %lu\n",
91 		(unsigned long)(ZONEID_PGOFF + ZONEID_SHIFT),
92 		(unsigned long)ZONEID_PGOFF);
93 	mminit_dprintk(MMINIT_TRACE, "pageflags_layout_usage",
94 		"location: %d -> %d layout %d -> %d unused %d -> %d page-flags\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 #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
101 	mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodeflags",
102 		"Last cpupid not in page flags");
103 #endif
104 
105 	if (SECTIONS_WIDTH) {
106 		shift -= SECTIONS_WIDTH;
107 		BUG_ON(shift != SECTIONS_PGSHIFT);
108 	}
109 	if (NODES_WIDTH) {
110 		shift -= NODES_WIDTH;
111 		BUG_ON(shift != NODES_PGSHIFT);
112 	}
113 	if (ZONES_WIDTH) {
114 		shift -= ZONES_WIDTH;
115 		BUG_ON(shift != ZONES_PGSHIFT);
116 	}
117 
118 	/* Check for bitmask overlaps */
119 	or_mask = (ZONES_MASK << ZONES_PGSHIFT) |
120 			(NODES_MASK << NODES_PGSHIFT) |
121 			(SECTIONS_MASK << SECTIONS_PGSHIFT);
122 	add_mask = (ZONES_MASK << ZONES_PGSHIFT) +
123 			(NODES_MASK << NODES_PGSHIFT) +
124 			(SECTIONS_MASK << SECTIONS_PGSHIFT);
125 	BUG_ON(or_mask != add_mask);
126 }
127 
128 static __init int set_mminit_loglevel(char *str)
129 {
130 	get_option(&str, &mminit_loglevel);
131 	return 0;
132 }
133 early_param("mminit_loglevel", set_mminit_loglevel);
134 #endif /* CONFIG_DEBUG_MEMORY_INIT */
135 
136 struct kobject *mm_kobj;
137 EXPORT_SYMBOL_GPL(mm_kobj);
138 
139 #ifdef CONFIG_SMP
140 s32 vm_committed_as_batch = 32;
141 
142 static void __meminit mm_compute_batch(void)
143 {
144 	u64 memsized_batch;
145 	s32 nr = num_present_cpus();
146 	s32 batch = max_t(s32, nr*2, 32);
147 
148 	/* batch size set to 0.4% of (total memory/#cpus), or max int32 */
149 	memsized_batch = min_t(u64, (totalram_pages/nr)/256, 0x7fffffff);
150 
151 	vm_committed_as_batch = max_t(s32, memsized_batch, batch);
152 }
153 
154 static int __meminit mm_compute_batch_notifier(struct notifier_block *self,
155 					unsigned long action, void *arg)
156 {
157 	switch (action) {
158 	case MEM_ONLINE:
159 	case MEM_OFFLINE:
160 		mm_compute_batch();
161 	default:
162 		break;
163 	}
164 	return NOTIFY_OK;
165 }
166 
167 static struct notifier_block compute_batch_nb __meminitdata = {
168 	.notifier_call = mm_compute_batch_notifier,
169 	.priority = IPC_CALLBACK_PRI, /* use lowest priority */
170 };
171 
172 static int __init mm_compute_batch_init(void)
173 {
174 	mm_compute_batch();
175 	register_hotmemory_notifier(&compute_batch_nb);
176 
177 	return 0;
178 }
179 
180 __initcall(mm_compute_batch_init);
181 
182 #endif
183 
184 static int __init mm_sysfs_init(void)
185 {
186 	mm_kobj = kobject_create_and_add("mm", kernel_kobj);
187 	if (!mm_kobj)
188 		return -ENOMEM;
189 
190 	return 0;
191 }
192 postcore_initcall(mm_sysfs_init);
193