Line data Source code
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. */
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 :
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 :
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 :
148 1 : void mm_compute_batch(int overcommit_policy)
149 : {
150 1 : u64 memsized_batch;
151 1 : s32 nr = num_present_cpus();
152 1 : s32 batch = max_t(s32, nr*2, 32);
153 1 : 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 1 : if (overcommit_policy == OVERCOMMIT_NEVER)
162 0 : memsized_batch = min_t(u64, ram_pages/nr/256, INT_MAX);
163 : else
164 1 : memsized_batch = min_t(u64, ram_pages/nr/4, INT_MAX);
165 :
166 1 : vm_committed_as_batch = max_t(s32, memsized_batch, batch);
167 1 : }
168 :
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 : break;
177 : default:
178 : break;
179 : }
180 : return NOTIFY_OK;
181 : }
182 :
183 : static struct notifier_block compute_batch_nb __meminitdata = {
184 : .notifier_call = mm_compute_batch_notifier,
185 : .priority = IPC_CALLBACK_PRI, /* use lowest priority */
186 : };
187 :
188 1 : static int __init mm_compute_batch_init(void)
189 : {
190 1 : mm_compute_batch(sysctl_overcommit_memory);
191 1 : register_hotmemory_notifier(&compute_batch_nb);
192 :
193 1 : return 0;
194 : }
195 :
196 : __initcall(mm_compute_batch_init);
197 :
198 : #endif
199 :
200 1 : static int __init mm_sysfs_init(void)
201 : {
202 1 : mm_kobj = kobject_create_and_add("mm", kernel_kobj);
203 1 : if (!mm_kobj)
204 0 : return -ENOMEM;
205 :
206 : return 0;
207 : }
208 : postcore_initcall(mm_sysfs_init);
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