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