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 - LRU_GEN_WIDTH - LRU_REFS_WIDTH;
69 mminit_dprintk(MMINIT_TRACE, "pageflags_layout_widths",
70 "Section %d Node %d Zone %d Lastcpupid %d Kasantag %d Gen %d Tier %d Flags %d\n",
71 SECTIONS_WIDTH,
72 NODES_WIDTH,
73 ZONES_WIDTH,
74 LAST_CPUPID_WIDTH,
75 KASAN_TAG_WIDTH,
76 LRU_GEN_WIDTH,
77 LRU_REFS_WIDTH,
78 NR_PAGEFLAGS);
79 mminit_dprintk(MMINIT_TRACE, "pageflags_layout_shifts",
80 "Section %d Node %d Zone %d Lastcpupid %d Kasantag %d\n",
81 SECTIONS_SHIFT,
82 NODES_SHIFT,
83 ZONES_SHIFT,
84 LAST_CPUPID_SHIFT,
85 KASAN_TAG_WIDTH);
86 mminit_dprintk(MMINIT_TRACE, "pageflags_layout_pgshifts",
87 "Section %lu Node %lu Zone %lu Lastcpupid %lu Kasantag %lu\n",
88 (unsigned long)SECTIONS_PGSHIFT,
89 (unsigned long)NODES_PGSHIFT,
90 (unsigned long)ZONES_PGSHIFT,
91 (unsigned long)LAST_CPUPID_PGSHIFT,
92 (unsigned long)KASAN_TAG_PGSHIFT);
93 mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodezoneid",
94 "Node/Zone ID: %lu -> %lu\n",
95 (unsigned long)(ZONEID_PGOFF + ZONEID_SHIFT),
96 (unsigned long)ZONEID_PGOFF);
97 mminit_dprintk(MMINIT_TRACE, "pageflags_layout_usage",
98 "location: %d -> %d layout %d -> %d unused %d -> %d page-flags\n",
99 shift, width, width, NR_PAGEFLAGS, NR_PAGEFLAGS, 0);
100 #ifdef NODE_NOT_IN_PAGE_FLAGS
101 mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodeflags",
102 "Node not in page flags");
103 #endif
104 #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
105 mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodeflags",
106 "Last cpupid not in page flags");
107 #endif
108
109 if (SECTIONS_WIDTH) {
110 shift -= SECTIONS_WIDTH;
111 BUG_ON(shift != SECTIONS_PGSHIFT);
112 }
113 if (NODES_WIDTH) {
114 shift -= NODES_WIDTH;
115 BUG_ON(shift != NODES_PGSHIFT);
116 }
117 if (ZONES_WIDTH) {
118 shift -= ZONES_WIDTH;
119 BUG_ON(shift != ZONES_PGSHIFT);
120 }
121
122 /* Check for bitmask overlaps */
123 or_mask = (ZONES_MASK << ZONES_PGSHIFT) |
124 (NODES_MASK << NODES_PGSHIFT) |
125 (SECTIONS_MASK << SECTIONS_PGSHIFT);
126 add_mask = (ZONES_MASK << ZONES_PGSHIFT) +
127 (NODES_MASK << NODES_PGSHIFT) +
128 (SECTIONS_MASK << SECTIONS_PGSHIFT);
129 BUG_ON(or_mask != add_mask);
130 }
131
set_mminit_loglevel(char * str)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 #ifdef CONFIG_SMP
144 s32 vm_committed_as_batch = 32;
145
mm_compute_batch(int overcommit_policy)146 void mm_compute_batch(int overcommit_policy)
147 {
148 u64 memsized_batch;
149 s32 nr = num_present_cpus();
150 s32 batch = max_t(s32, nr*2, 32);
151 unsigned long ram_pages = totalram_pages();
152
153 /*
154 * For policy OVERCOMMIT_NEVER, set batch size to 0.4% of
155 * (total memory/#cpus), and lift it to 25% for other policies
156 * to easy the possible lock contention for percpu_counter
157 * vm_committed_as, while the max limit is INT_MAX
158 */
159 if (overcommit_policy == OVERCOMMIT_NEVER)
160 memsized_batch = min_t(u64, ram_pages/nr/256, INT_MAX);
161 else
162 memsized_batch = min_t(u64, ram_pages/nr/4, INT_MAX);
163
164 vm_committed_as_batch = max_t(s32, memsized_batch, batch);
165 }
166
mm_compute_batch_notifier(struct notifier_block * self,unsigned long action,void * arg)167 static int __meminit mm_compute_batch_notifier(struct notifier_block *self,
168 unsigned long action, void *arg)
169 {
170 switch (action) {
171 case MEM_ONLINE:
172 case MEM_OFFLINE:
173 mm_compute_batch(sysctl_overcommit_memory);
174 break;
175 default:
176 break;
177 }
178 return NOTIFY_OK;
179 }
180
181 static struct notifier_block compute_batch_nb __meminitdata = {
182 .notifier_call = mm_compute_batch_notifier,
183 .priority = IPC_CALLBACK_PRI, /* use lowest priority */
184 };
185
mm_compute_batch_init(void)186 static int __init mm_compute_batch_init(void)
187 {
188 mm_compute_batch(sysctl_overcommit_memory);
189 register_hotmemory_notifier(&compute_batch_nb);
190
191 return 0;
192 }
193
194 __initcall(mm_compute_batch_init);
195
196 #endif
197
mm_sysfs_init(void)198 static int __init mm_sysfs_init(void)
199 {
200 mm_kobj = kobject_create_and_add("mm", kernel_kobj);
201 if (!mm_kobj)
202 return -ENOMEM;
203
204 return 0;
205 }
206 postcore_initcall(mm_sysfs_init);
207
