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 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 } 168 169 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 static int __init mm_compute_batch_init(void) 189 { 190 mm_compute_batch(sysctl_overcommit_memory); 191 register_hotmemory_notifier(&compute_batch_nb); 192 193 return 0; 194 } 195 196 __initcall(mm_compute_batch_init); 197 198 #endif 199 200 static int __init mm_sysfs_init(void) 201 { 202 mm_kobj = kobject_create_and_add("mm", kernel_kobj); 203 if (!mm_kobj) 204 return -ENOMEM; 205 206 return 0; 207 } 208 postcore_initcall(mm_sysfs_init); 209