1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * mm_init.c - Memory initialisation verification and debugging
4 *
5 * Copyright 2008 IBM Corporation, 2008
6 * Author Mel Gorman <mel@csn.ul.ie>
7 *
8 */
9 #include <linux/kernel.h>
10 #include <linux/init.h>
11 #include <linux/kobject.h>
12 #include <linux/export.h>
13 #include <linux/memory.h>
14 #include <linux/notifier.h>
15 #include <linux/sched.h>
16 #include <linux/mman.h>
17 #include "internal.h"
18
19 #ifdef CONFIG_DEBUG_MEMORY_INIT
20 int __meminitdata mminit_loglevel;
21
22 #ifndef SECTIONS_SHIFT
23 #define SECTIONS_SHIFT 0
24 #endif
25
26 /* The zonelists are simply reported, validation is manual. */
mminit_verify_zonelist(void)27 void __init mminit_verify_zonelist(void)
28 {
29 int nid;
30
31 if (mminit_loglevel < MMINIT_VERIFY)
32 return;
33
34 for_each_online_node(nid) {
35 pg_data_t *pgdat = NODE_DATA(nid);
36 struct zone *zone;
37 struct zoneref *z;
38 struct zonelist *zonelist;
39 int i, listid, zoneid;
40
41 BUILD_BUG_ON(MAX_ZONELISTS > 2);
42 for (i = 0; i < MAX_ZONELISTS * MAX_NR_ZONES; i++) {
43
44 /* Identify the zone and nodelist */
45 zoneid = i % MAX_NR_ZONES;
46 listid = i / MAX_NR_ZONES;
47 zonelist = &pgdat->node_zonelists[listid];
48 zone = &pgdat->node_zones[zoneid];
49 if (!populated_zone(zone))
50 continue;
51
52 /* Print information about the zonelist */
53 printk(KERN_DEBUG "mminit::zonelist %s %d:%s = ",
54 listid > 0 ? "thisnode" : "general", nid,
55 zone->name);
56
57 /* Iterate the zonelist */
58 for_each_zone_zonelist(zone, z, zonelist, zoneid)
59 pr_cont("%d:%s ", zone_to_nid(zone), zone->name);
60 pr_cont("\n");
61 }
62 }
63 }
64
mminit_verify_pageflags_layout(void)65 void __init mminit_verify_pageflags_layout(void)
66 {
67 int shift, width;
68 unsigned long or_mask, add_mask;
69
70 shift = 8 * sizeof(unsigned long);
71 width = shift - SECTIONS_WIDTH - NODES_WIDTH - ZONES_WIDTH
72 - LAST_CPUPID_SHIFT - KASAN_TAG_WIDTH;
73 mminit_dprintk(MMINIT_TRACE, "pageflags_layout_widths",
74 "Section %d Node %d Zone %d Lastcpupid %d Kasantag %d Flags %d\n",
75 SECTIONS_WIDTH,
76 NODES_WIDTH,
77 ZONES_WIDTH,
78 LAST_CPUPID_WIDTH,
79 KASAN_TAG_WIDTH,
80 NR_PAGEFLAGS);
81 mminit_dprintk(MMINIT_TRACE, "pageflags_layout_shifts",
82 "Section %d Node %d Zone %d Lastcpupid %d Kasantag %d\n",
83 SECTIONS_SHIFT,
84 NODES_SHIFT,
85 ZONES_SHIFT,
86 LAST_CPUPID_SHIFT,
87 KASAN_TAG_WIDTH);
88 mminit_dprintk(MMINIT_TRACE, "pageflags_layout_pgshifts",
89 "Section %lu Node %lu Zone %lu Lastcpupid %lu Kasantag %lu\n",
90 (unsigned long)SECTIONS_PGSHIFT,
91 (unsigned long)NODES_PGSHIFT,
92 (unsigned long)ZONES_PGSHIFT,
93 (unsigned long)LAST_CPUPID_PGSHIFT,
94 (unsigned long)KASAN_TAG_PGSHIFT);
95 mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodezoneid",
96 "Node/Zone ID: %lu -> %lu\n",
97 (unsigned long)(ZONEID_PGOFF + ZONEID_SHIFT),
98 (unsigned long)ZONEID_PGOFF);
99 mminit_dprintk(MMINIT_TRACE, "pageflags_layout_usage",
100 "location: %d -> %d layout %d -> %d unused %d -> %d page-flags\n",
101 shift, width, width, NR_PAGEFLAGS, NR_PAGEFLAGS, 0);
102 #ifdef NODE_NOT_IN_PAGE_FLAGS
103 mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodeflags",
104 "Node not in page flags");
105 #endif
106 #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
107 mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodeflags",
108 "Last cpupid not in page flags");
109 #endif
110
111 if (SECTIONS_WIDTH) {
112 shift -= SECTIONS_WIDTH;
113 BUG_ON(shift != SECTIONS_PGSHIFT);
114 }
115 if (NODES_WIDTH) {
116 shift -= NODES_WIDTH;
117 BUG_ON(shift != NODES_PGSHIFT);
118 }
119 if (ZONES_WIDTH) {
120 shift -= ZONES_WIDTH;
121 BUG_ON(shift != ZONES_PGSHIFT);
122 }
123
124 /* Check for bitmask overlaps */
125 or_mask = (ZONES_MASK << ZONES_PGSHIFT) |
126 (NODES_MASK << NODES_PGSHIFT) |
127 (SECTIONS_MASK << SECTIONS_PGSHIFT);
128 add_mask = (ZONES_MASK << ZONES_PGSHIFT) +
129 (NODES_MASK << NODES_PGSHIFT) +
130 (SECTIONS_MASK << SECTIONS_PGSHIFT);
131 BUG_ON(or_mask != add_mask);
132 }
133
set_mminit_loglevel(char * str)134 static __init int set_mminit_loglevel(char *str)
135 {
136 get_option(&str, &mminit_loglevel);
137 return 0;
138 }
139 early_param("mminit_loglevel", set_mminit_loglevel);
140 #endif /* CONFIG_DEBUG_MEMORY_INIT */
141
142 struct kobject *mm_kobj;
143 EXPORT_SYMBOL_GPL(mm_kobj);
144
145 #ifdef CONFIG_SMP
146 s32 vm_committed_as_batch = 32;
147
mm_compute_batch(int overcommit_policy)148 void mm_compute_batch(int overcommit_policy)
149 {
150 u64 memsized_batch;
151 s32 nr = num_present_cpus();
152 s32 batch = max_t(s32, nr*2, 32);
153 unsigned long ram_pages = totalram_pages();
154
155 /*
156 * For policy OVERCOMMIT_NEVER, set batch size to 0.4% of
157 * (total memory/#cpus), and lift it to 25% for other policies
158 * to easy the possible lock contention for percpu_counter
159 * vm_committed_as, while the max limit is INT_MAX
160 */
161 if (overcommit_policy == OVERCOMMIT_NEVER)
162 memsized_batch = min_t(u64, ram_pages/nr/256, INT_MAX);
163 else
164 memsized_batch = min_t(u64, ram_pages/nr/4, INT_MAX);
165
166 vm_committed_as_batch = max_t(s32, memsized_batch, batch);
167 }
168
mm_compute_batch_notifier(struct notifier_block * self,unsigned long action,void * arg)169 static int __meminit mm_compute_batch_notifier(struct notifier_block *self,
170 unsigned long action, void *arg)
171 {
172 switch (action) {
173 case MEM_ONLINE:
174 case MEM_OFFLINE:
175 mm_compute_batch(sysctl_overcommit_memory);
176 default:
177 break;
178 }
179 return NOTIFY_OK;
180 }
181
182 static struct notifier_block compute_batch_nb __meminitdata = {
183 .notifier_call = mm_compute_batch_notifier,
184 .priority = IPC_CALLBACK_PRI, /* use lowest priority */
185 };
186
mm_compute_batch_init(void)187 static int __init mm_compute_batch_init(void)
188 {
189 mm_compute_batch(sysctl_overcommit_memory);
190 register_hotmemory_notifier(&compute_batch_nb);
191
192 return 0;
193 }
194
195 __initcall(mm_compute_batch_init);
196
197 #endif
198
mm_sysfs_init(void)199 static int __init mm_sysfs_init(void)
200 {
201 mm_kobj = kobject_create_and_add("mm", kernel_kobj);
202 if (!mm_kobj)
203 return -ENOMEM;
204
205 return 0;
206 }
207 postcore_initcall(mm_sysfs_init);
208