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. */ 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 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 } 129 130 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; 143 144 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 } 164 165 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 }; 183 184 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 195 196 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