1// SPDX-License-Identifier: GPL-2.0-only 2/* 3 * linux/mm/vmstat.c 4 * 5 * Manages VM statistics 6 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds 7 * 8 * zoned VM statistics 9 * Copyright (C) 2006 Silicon Graphics, Inc., 10 * Christoph Lameter <christoph@lameter.com> 11 * Copyright (C) 2008-2014 Christoph Lameter 12 */ 13#include <linux/fs.h> 14#include <linux/mm.h> 15#include <linux/err.h> 16#include <linux/module.h> 17#include <linux/slab.h> 18#include <linux/cpu.h> 19#include <linux/cpumask.h> 20#include <linux/vmstat.h> 21#include <linux/proc_fs.h> 22#include <linux/seq_file.h> 23#include <linux/debugfs.h> 24#include <linux/sched.h> 25#include <linux/math64.h> 26#include <linux/writeback.h> 27#include <linux/compaction.h> 28#include <linux/mm_inline.h> 29#include <linux/page_owner.h> 30#include <linux/sched/isolation.h> 31 32#include "internal.h" 33 34#ifdef CONFIG_NUMA 35int sysctl_vm_numa_stat = ENABLE_NUMA_STAT; 36 37/* zero numa counters within a zone */ 38static void zero_zone_numa_counters(struct zone *zone) 39{ 40 int item, cpu; 41 42 for (item = 0; item < NR_VM_NUMA_EVENT_ITEMS; item++) { 43 atomic_long_set(&zone->vm_numa_event[item], 0); 44 for_each_online_cpu(cpu) { 45 per_cpu_ptr(zone->per_cpu_zonestats, cpu)->vm_numa_event[item] 46 = 0; 47 } 48 } 49} 50 51/* zero numa counters of all the populated zones */ 52static void zero_zones_numa_counters(void) 53{ 54 struct zone *zone; 55 56 for_each_populated_zone(zone) 57 zero_zone_numa_counters(zone); 58} 59 60/* zero global numa counters */ 61static void zero_global_numa_counters(void) 62{ 63 int item; 64 65 for (item = 0; item < NR_VM_NUMA_EVENT_ITEMS; item++) 66 atomic_long_set(&vm_numa_event[item], 0); 67} 68 69static void invalid_numa_statistics(void) 70{ 71 zero_zones_numa_counters(); 72 zero_global_numa_counters(); 73} 74 75static DEFINE_MUTEX(vm_numa_stat_lock); 76 77int sysctl_vm_numa_stat_handler(struct ctl_table *table, int write, 78 void *buffer, size_t *length, loff_t *ppos) 79{ 80 int ret, oldval; 81 82 mutex_lock(&vm_numa_stat_lock); 83 if (write) 84 oldval = sysctl_vm_numa_stat; 85 ret = proc_dointvec_minmax(table, write, buffer, length, ppos); 86 if (ret || !write) 87 goto out; 88 89 if (oldval == sysctl_vm_numa_stat) 90 goto out; 91 else if (sysctl_vm_numa_stat == ENABLE_NUMA_STAT) { 92 static_branch_enable(&vm_numa_stat_key); 93 pr_info("enable numa statistics\n"); 94 } else { 95 static_branch_disable(&vm_numa_stat_key); 96 invalid_numa_statistics(); 97 pr_info("disable numa statistics, and clear numa counters\n"); 98 } 99 100out: 101 mutex_unlock(&vm_numa_stat_lock); 102 return ret; 103} 104#endif 105 106#ifdef CONFIG_VM_EVENT_COUNTERS 107DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}}; 108EXPORT_PER_CPU_SYMBOL(vm_event_states); 109 110static void sum_vm_events(unsigned long *ret) 111{ 112 int cpu; 113 int i; 114 115 memset(ret, 0, NR_VM_EVENT_ITEMS * sizeof(unsigned long)); 116 117 for_each_online_cpu(cpu) { 118 struct vm_event_state *this = &per_cpu(vm_event_states, cpu); 119 120 for (i = 0; i < NR_VM_EVENT_ITEMS; i++) 121 ret[i] += this->event[i]; 122 } 123} 124 125/* 126 * Accumulate the vm event counters across all CPUs. 127 * The result is unavoidably approximate - it can change 128 * during and after execution of this function. 129*/ 130void all_vm_events(unsigned long *ret) 131{ 132 cpus_read_lock(); 133 sum_vm_events(ret); 134 cpus_read_unlock(); 135} 136EXPORT_SYMBOL_GPL(all_vm_events); 137 138/* 139 * Fold the foreign cpu events into our own. 140 * 141 * This is adding to the events on one processor 142 * but keeps the global counts constant. 143 */ 144void vm_events_fold_cpu(int cpu) 145{ 146 struct vm_event_state *fold_state = &per_cpu(vm_event_states, cpu); 147 int i; 148 149 for (i = 0; i < NR_VM_EVENT_ITEMS; i++) { 150 count_vm_events(i, fold_state->event[i]); 151 fold_state->event[i] = 0; 152 } 153} 154 155#endif /* CONFIG_VM_EVENT_COUNTERS */ 156 157/* 158 * Manage combined zone based / global counters 159 * 160 * vm_stat contains the global counters 161 */ 162atomic_long_t vm_zone_stat[NR_VM_ZONE_STAT_ITEMS] __cacheline_aligned_in_smp; 163atomic_long_t vm_node_stat[NR_VM_NODE_STAT_ITEMS] __cacheline_aligned_in_smp; 164atomic_long_t vm_numa_event[NR_VM_NUMA_EVENT_ITEMS] __cacheline_aligned_in_smp; 165EXPORT_SYMBOL(vm_zone_stat); 166EXPORT_SYMBOL(vm_node_stat); 167 168#ifdef CONFIG_NUMA 169static void fold_vm_zone_numa_events(struct zone *zone) 170{ 171 unsigned long zone_numa_events[NR_VM_NUMA_EVENT_ITEMS] = { 0, }; 172 int cpu; 173 enum numa_stat_item item; 174 175 for_each_online_cpu(cpu) { 176 struct per_cpu_zonestat *pzstats; 177 178 pzstats = per_cpu_ptr(zone->per_cpu_zonestats, cpu); 179 for (item = 0; item < NR_VM_NUMA_EVENT_ITEMS; item++) 180 zone_numa_events[item] += xchg(&pzstats->vm_numa_event[item], 0); 181 } 182 183 for (item = 0; item < NR_VM_NUMA_EVENT_ITEMS; item++) 184 zone_numa_event_add(zone_numa_events[item], zone, item); 185} 186 187void fold_vm_numa_events(void) 188{ 189 struct zone *zone; 190 191 for_each_populated_zone(zone) 192 fold_vm_zone_numa_events(zone); 193} 194#endif 195 196#ifdef CONFIG_SMP 197 198int calculate_pressure_threshold(struct zone *zone) 199{ 200 int threshold; 201 int watermark_distance; 202 203 /* 204 * As vmstats are not up to date, there is drift between the estimated 205 * and real values. For high thresholds and a high number of CPUs, it 206 * is possible for the min watermark to be breached while the estimated 207 * value looks fine. The pressure threshold is a reduced value such 208 * that even the maximum amount of drift will not accidentally breach 209 * the min watermark 210 */ 211 watermark_distance = low_wmark_pages(zone) - min_wmark_pages(zone); 212 threshold = max(1, (int)(watermark_distance / num_online_cpus())); 213 214 /* 215 * Maximum threshold is 125 216 */ 217 threshold = min(125, threshold); 218 219 return threshold; 220} 221 222int calculate_normal_threshold(struct zone *zone) 223{ 224 int threshold; 225 int mem; /* memory in 128 MB units */ 226 227 /* 228 * The threshold scales with the number of processors and the amount 229 * of memory per zone. More memory means that we can defer updates for 230 * longer, more processors could lead to more contention. 231 * fls() is used to have a cheap way of logarithmic scaling. 232 * 233 * Some sample thresholds: 234 * 235 * Threshold Processors (fls) Zonesize fls(mem)+1 236 * ------------------------------------------------------------------ 237 * 8 1 1 0.9-1 GB 4 238 * 16 2 2 0.9-1 GB 4 239 * 20 2 2 1-2 GB 5 240 * 24 2 2 2-4 GB 6 241 * 28 2 2 4-8 GB 7 242 * 32 2 2 8-16 GB 8 243 * 4 2 2 <128M 1 244 * 30 4 3 2-4 GB 5 245 * 48 4 3 8-16 GB 8 246 * 32 8 4 1-2 GB 4 247 * 32 8 4 0.9-1GB 4 248 * 10 16 5 <128M 1 249 * 40 16 5 900M 4 250 * 70 64 7 2-4 GB 5 251 * 84 64 7 4-8 GB 6 252 * 108 512 9 4-8 GB 6 253 * 125 1024 10 8-16 GB 8 254 * 125 1024 10 16-32 GB 9 255 */ 256 257 mem = zone_managed_pages(zone) >> (27 - PAGE_SHIFT); 258 259 threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem)); 260 261 /* 262 * Maximum threshold is 125 263 */ 264 threshold = min(125, threshold); 265 266 return threshold; 267} 268 269/* 270 * Refresh the thresholds for each zone. 271 */ 272void refresh_zone_stat_thresholds(void) 273{ 274 struct pglist_data *pgdat; 275 struct zone *zone; 276 int cpu; 277 int threshold; 278 279 /* Zero current pgdat thresholds */ 280 for_each_online_pgdat(pgdat) { 281 for_each_online_cpu(cpu) { 282 per_cpu_ptr(pgdat->per_cpu_nodestats, cpu)->stat_threshold = 0; 283 } 284 } 285 286 for_each_populated_zone(zone) { 287 struct pglist_data *pgdat = zone->zone_pgdat; 288 unsigned long max_drift, tolerate_drift; 289 290 threshold = calculate_normal_threshold(zone); 291 292 for_each_online_cpu(cpu) { 293 int pgdat_threshold; 294 295 per_cpu_ptr(zone->per_cpu_zonestats, cpu)->stat_threshold 296 = threshold; 297 298 /* Base nodestat threshold on the largest populated zone. */ 299 pgdat_threshold = per_cpu_ptr(pgdat->per_cpu_nodestats, cpu)->stat_threshold; 300 per_cpu_ptr(pgdat->per_cpu_nodestats, cpu)->stat_threshold 301 = max(threshold, pgdat_threshold); 302 } 303 304 /* 305 * Only set percpu_drift_mark if there is a danger that 306 * NR_FREE_PAGES reports the low watermark is ok when in fact 307 * the min watermark could be breached by an allocation 308 */ 309 tolerate_drift = low_wmark_pages(zone) - min_wmark_pages(zone); 310 max_drift = num_online_cpus() * threshold; 311 if (max_drift > tolerate_drift) 312 zone->percpu_drift_mark = high_wmark_pages(zone) + 313 max_drift; 314 } 315} 316 317void set_pgdat_percpu_threshold(pg_data_t *pgdat, 318 int (*calculate_pressure)(struct zone *)) 319{ 320 struct zone *zone; 321 int cpu; 322 int threshold; 323 int i; 324 325 for (i = 0; i < pgdat->nr_zones; i++) { 326 zone = &pgdat->node_zones[i]; 327 if (!zone->percpu_drift_mark) 328 continue; 329 330 threshold = (*calculate_pressure)(zone); 331 for_each_online_cpu(cpu) 332 per_cpu_ptr(zone->per_cpu_zonestats, cpu)->stat_threshold 333 = threshold; 334 } 335} 336 337/* 338 * For use when we know that interrupts are disabled, 339 * or when we know that preemption is disabled and that 340 * particular counter cannot be updated from interrupt context. 341 */ 342void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item, 343 long delta) 344{ 345 struct per_cpu_zonestat __percpu *pcp = zone->per_cpu_zonestats; 346 s8 __percpu *p = pcp->vm_stat_diff + item; 347 long x; 348 long t; 349 350 /* 351 * Accurate vmstat updates require a RMW. On !PREEMPT_RT kernels, 352 * atomicity is provided by IRQs being disabled -- either explicitly 353 * or via local_lock_irq. On PREEMPT_RT, local_lock_irq only disables 354 * CPU migrations and preemption potentially corrupts a counter so 355 * disable preemption. 356 */ 357 preempt_disable_nested(); 358 359 x = delta + __this_cpu_read(*p); 360 361 t = __this_cpu_read(pcp->stat_threshold); 362 363 if (unlikely(abs(x) > t)) { 364 zone_page_state_add(x, zone, item); 365 x = 0; 366 } 367 __this_cpu_write(*p, x); 368 369 preempt_enable_nested(); 370} 371EXPORT_SYMBOL(__mod_zone_page_state); 372 373void __mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item, 374 long delta) 375{ 376 struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats; 377 s8 __percpu *p = pcp->vm_node_stat_diff + item; 378 long x; 379 long t; 380 381 if (vmstat_item_in_bytes(item)) { 382 /* 383 * Only cgroups use subpage accounting right now; at 384 * the global level, these items still change in 385 * multiples of whole pages. Store them as pages 386 * internally to keep the per-cpu counters compact. 387 */ 388 VM_WARN_ON_ONCE(delta & (PAGE_SIZE - 1)); 389 delta >>= PAGE_SHIFT; 390 } 391 392 /* See __mod_node_page_state */ 393 preempt_disable_nested(); 394 395 x = delta + __this_cpu_read(*p); 396 397 t = __this_cpu_read(pcp->stat_threshold); 398 399 if (unlikely(abs(x) > t)) { 400 node_page_state_add(x, pgdat, item); 401 x = 0; 402 } 403 __this_cpu_write(*p, x); 404 405 preempt_enable_nested(); 406} 407EXPORT_SYMBOL(__mod_node_page_state); 408 409/* 410 * Optimized increment and decrement functions. 411 * 412 * These are only for a single page and therefore can take a struct page * 413 * argument instead of struct zone *. This allows the inclusion of the code 414 * generated for page_zone(page) into the optimized functions. 415 * 416 * No overflow check is necessary and therefore the differential can be 417 * incremented or decremented in place which may allow the compilers to 418 * generate better code. 419 * The increment or decrement is known and therefore one boundary check can 420 * be omitted. 421 * 422 * NOTE: These functions are very performance sensitive. Change only 423 * with care. 424 * 425 * Some processors have inc/dec instructions that are atomic vs an interrupt. 426 * However, the code must first determine the differential location in a zone 427 * based on the processor number and then inc/dec the counter. There is no 428 * guarantee without disabling preemption that the processor will not change 429 * in between and therefore the atomicity vs. interrupt cannot be exploited 430 * in a useful way here. 431 */ 432void __inc_zone_state(struct zone *zone, enum zone_stat_item item) 433{ 434 struct per_cpu_zonestat __percpu *pcp = zone->per_cpu_zonestats; 435 s8 __percpu *p = pcp->vm_stat_diff + item; 436 s8 v, t; 437 438 /* See __mod_node_page_state */ 439 preempt_disable_nested(); 440 441 v = __this_cpu_inc_return(*p); 442 t = __this_cpu_read(pcp->stat_threshold); 443 if (unlikely(v > t)) { 444 s8 overstep = t >> 1; 445 446 zone_page_state_add(v + overstep, zone, item); 447 __this_cpu_write(*p, -overstep); 448 } 449 450 preempt_enable_nested(); 451} 452 453void __inc_node_state(struct pglist_data *pgdat, enum node_stat_item item) 454{ 455 struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats; 456 s8 __percpu *p = pcp->vm_node_stat_diff + item; 457 s8 v, t; 458 459 VM_WARN_ON_ONCE(vmstat_item_in_bytes(item)); 460 461 /* See __mod_node_page_state */ 462 preempt_disable_nested(); 463 464 v = __this_cpu_inc_return(*p); 465 t = __this_cpu_read(pcp->stat_threshold); 466 if (unlikely(v > t)) { 467 s8 overstep = t >> 1; 468 469 node_page_state_add(v + overstep, pgdat, item); 470 __this_cpu_write(*p, -overstep); 471 } 472 473 preempt_enable_nested(); 474} 475 476void __inc_zone_page_state(struct page *page, enum zone_stat_item item) 477{ 478 __inc_zone_state(page_zone(page), item); 479} 480EXPORT_SYMBOL(__inc_zone_page_state); 481 482void __inc_node_page_state(struct page *page, enum node_stat_item item) 483{ 484 __inc_node_state(page_pgdat(page), item); 485} 486EXPORT_SYMBOL(__inc_node_page_state); 487 488void __dec_zone_state(struct zone *zone, enum zone_stat_item item) 489{ 490 struct per_cpu_zonestat __percpu *pcp = zone->per_cpu_zonestats; 491 s8 __percpu *p = pcp->vm_stat_diff + item; 492 s8 v, t; 493 494 /* See __mod_node_page_state */ 495 preempt_disable_nested(); 496 497 v = __this_cpu_dec_return(*p); 498 t = __this_cpu_read(pcp->stat_threshold); 499 if (unlikely(v < - t)) { 500 s8 overstep = t >> 1; 501 502 zone_page_state_add(v - overstep, zone, item); 503 __this_cpu_write(*p, overstep); 504 } 505 506 preempt_enable_nested(); 507} 508 509void __dec_node_state(struct pglist_data *pgdat, enum node_stat_item item) 510{ 511 struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats; 512 s8 __percpu *p = pcp->vm_node_stat_diff + item; 513 s8 v, t; 514 515 VM_WARN_ON_ONCE(vmstat_item_in_bytes(item)); 516 517 /* See __mod_node_page_state */ 518 preempt_disable_nested(); 519 520 v = __this_cpu_dec_return(*p); 521 t = __this_cpu_read(pcp->stat_threshold); 522 if (unlikely(v < - t)) { 523 s8 overstep = t >> 1; 524 525 node_page_state_add(v - overstep, pgdat, item); 526 __this_cpu_write(*p, overstep); 527 } 528 529 preempt_enable_nested(); 530} 531 532void __dec_zone_page_state(struct page *page, enum zone_stat_item item) 533{ 534 __dec_zone_state(page_zone(page), item); 535} 536EXPORT_SYMBOL(__dec_zone_page_state); 537 538void __dec_node_page_state(struct page *page, enum node_stat_item item) 539{ 540 __dec_node_state(page_pgdat(page), item); 541} 542EXPORT_SYMBOL(__dec_node_page_state); 543 544#ifdef CONFIG_HAVE_CMPXCHG_LOCAL 545/* 546 * If we have cmpxchg_local support then we do not need to incur the overhead 547 * that comes with local_irq_save/restore if we use this_cpu_cmpxchg. 548 * 549 * mod_state() modifies the zone counter state through atomic per cpu 550 * operations. 551 * 552 * Overstep mode specifies how overstep should handled: 553 * 0 No overstepping 554 * 1 Overstepping half of threshold 555 * -1 Overstepping minus half of threshold 556*/ 557static inline void mod_zone_state(struct zone *zone, 558 enum zone_stat_item item, long delta, int overstep_mode) 559{ 560 struct per_cpu_zonestat __percpu *pcp = zone->per_cpu_zonestats; 561 s8 __percpu *p = pcp->vm_stat_diff + item; 562 long n, t, z; 563 s8 o; 564 565 o = this_cpu_read(*p); 566 do { 567 z = 0; /* overflow to zone counters */ 568 569 /* 570 * The fetching of the stat_threshold is racy. We may apply 571 * a counter threshold to the wrong the cpu if we get 572 * rescheduled while executing here. However, the next 573 * counter update will apply the threshold again and 574 * therefore bring the counter under the threshold again. 575 * 576 * Most of the time the thresholds are the same anyways 577 * for all cpus in a zone. 578 */ 579 t = this_cpu_read(pcp->stat_threshold); 580 581 n = delta + (long)o; 582 583 if (abs(n) > t) { 584 int os = overstep_mode * (t >> 1) ; 585 586 /* Overflow must be added to zone counters */ 587 z = n + os; 588 n = -os; 589 } 590 } while (!this_cpu_try_cmpxchg(*p, &o, n)); 591 592 if (z) 593 zone_page_state_add(z, zone, item); 594} 595 596void mod_zone_page_state(struct zone *zone, enum zone_stat_item item, 597 long delta) 598{ 599 mod_zone_state(zone, item, delta, 0); 600} 601EXPORT_SYMBOL(mod_zone_page_state); 602 603void inc_zone_page_state(struct page *page, enum zone_stat_item item) 604{ 605 mod_zone_state(page_zone(page), item, 1, 1); 606} 607EXPORT_SYMBOL(inc_zone_page_state); 608 609void dec_zone_page_state(struct page *page, enum zone_stat_item item) 610{ 611 mod_zone_state(page_zone(page), item, -1, -1); 612} 613EXPORT_SYMBOL(dec_zone_page_state); 614 615static inline void mod_node_state(struct pglist_data *pgdat, 616 enum node_stat_item item, int delta, int overstep_mode) 617{ 618 struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats; 619 s8 __percpu *p = pcp->vm_node_stat_diff + item; 620 long n, t, z; 621 s8 o; 622 623 if (vmstat_item_in_bytes(item)) { 624 /* 625 * Only cgroups use subpage accounting right now; at 626 * the global level, these items still change in 627 * multiples of whole pages. Store them as pages 628 * internally to keep the per-cpu counters compact. 629 */ 630 VM_WARN_ON_ONCE(delta & (PAGE_SIZE - 1)); 631 delta >>= PAGE_SHIFT; 632 } 633 634 o = this_cpu_read(*p); 635 do { 636 z = 0; /* overflow to node counters */ 637 638 /* 639 * The fetching of the stat_threshold is racy. We may apply 640 * a counter threshold to the wrong the cpu if we get 641 * rescheduled while executing here. However, the next 642 * counter update will apply the threshold again and 643 * therefore bring the counter under the threshold again. 644 * 645 * Most of the time the thresholds are the same anyways 646 * for all cpus in a node. 647 */ 648 t = this_cpu_read(pcp->stat_threshold); 649 650 n = delta + (long)o; 651 652 if (abs(n) > t) { 653 int os = overstep_mode * (t >> 1) ; 654 655 /* Overflow must be added to node counters */ 656 z = n + os; 657 n = -os; 658 } 659 } while (!this_cpu_try_cmpxchg(*p, &o, n)); 660 661 if (z) 662 node_page_state_add(z, pgdat, item); 663} 664 665void mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item, 666 long delta) 667{ 668 mod_node_state(pgdat, item, delta, 0); 669} 670EXPORT_SYMBOL(mod_node_page_state); 671 672void inc_node_state(struct pglist_data *pgdat, enum node_stat_item item) 673{ 674 mod_node_state(pgdat, item, 1, 1); 675} 676 677void inc_node_page_state(struct page *page, enum node_stat_item item) 678{ 679 mod_node_state(page_pgdat(page), item, 1, 1); 680} 681EXPORT_SYMBOL(inc_node_page_state); 682 683void dec_node_page_state(struct page *page, enum node_stat_item item) 684{ 685 mod_node_state(page_pgdat(page), item, -1, -1); 686} 687EXPORT_SYMBOL(dec_node_page_state); 688#else 689/* 690 * Use interrupt disable to serialize counter updates 691 */ 692void mod_zone_page_state(struct zone *zone, enum zone_stat_item item, 693 long delta) 694{ 695 unsigned long flags; 696 697 local_irq_save(flags); 698 __mod_zone_page_state(zone, item, delta); 699 local_irq_restore(flags); 700} 701EXPORT_SYMBOL(mod_zone_page_state); 702 703void inc_zone_page_state(struct page *page, enum zone_stat_item item) 704{ 705 unsigned long flags; 706 struct zone *zone; 707 708 zone = page_zone(page); 709 local_irq_save(flags); 710 __inc_zone_state(zone, item); 711 local_irq_restore(flags); 712} 713EXPORT_SYMBOL(inc_zone_page_state); 714 715void dec_zone_page_state(struct page *page, enum zone_stat_item item) 716{ 717 unsigned long flags; 718 719 local_irq_save(flags); 720 __dec_zone_page_state(page, item); 721 local_irq_restore(flags); 722} 723EXPORT_SYMBOL(dec_zone_page_state); 724 725void inc_node_state(struct pglist_data *pgdat, enum node_stat_item item) 726{ 727 unsigned long flags; 728 729 local_irq_save(flags); 730 __inc_node_state(pgdat, item); 731 local_irq_restore(flags); 732} 733EXPORT_SYMBOL(inc_node_state); 734 735void mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item, 736 long delta) 737{ 738 unsigned long flags; 739 740 local_irq_save(flags); 741 __mod_node_page_state(pgdat, item, delta); 742 local_irq_restore(flags); 743} 744EXPORT_SYMBOL(mod_node_page_state); 745 746void inc_node_page_state(struct page *page, enum node_stat_item item) 747{ 748 unsigned long flags; 749 struct pglist_data *pgdat; 750 751 pgdat = page_pgdat(page); 752 local_irq_save(flags); 753 __inc_node_state(pgdat, item); 754 local_irq_restore(flags); 755} 756EXPORT_SYMBOL(inc_node_page_state); 757 758void dec_node_page_state(struct page *page, enum node_stat_item item) 759{ 760 unsigned long flags; 761 762 local_irq_save(flags); 763 __dec_node_page_state(page, item); 764 local_irq_restore(flags); 765} 766EXPORT_SYMBOL(dec_node_page_state); 767#endif 768 769/* 770 * Fold a differential into the global counters. 771 * Returns the number of counters updated. 772 */ 773static int fold_diff(int *zone_diff, int *node_diff) 774{ 775 int i; 776 int changes = 0; 777 778 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) 779 if (zone_diff[i]) { 780 atomic_long_add(zone_diff[i], &vm_zone_stat[i]); 781 changes++; 782 } 783 784 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) 785 if (node_diff[i]) { 786 atomic_long_add(node_diff[i], &vm_node_stat[i]); 787 changes++; 788 } 789 return changes; 790} 791 792/* 793 * Update the zone counters for the current cpu. 794 * 795 * Note that refresh_cpu_vm_stats strives to only access 796 * node local memory. The per cpu pagesets on remote zones are placed 797 * in the memory local to the processor using that pageset. So the 798 * loop over all zones will access a series of cachelines local to 799 * the processor. 800 * 801 * The call to zone_page_state_add updates the cachelines with the 802 * statistics in the remote zone struct as well as the global cachelines 803 * with the global counters. These could cause remote node cache line 804 * bouncing and will have to be only done when necessary. 805 * 806 * The function returns the number of global counters updated. 807 */ 808static int refresh_cpu_vm_stats(bool do_pagesets) 809{ 810 struct pglist_data *pgdat; 811 struct zone *zone; 812 int i; 813 int global_zone_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, }; 814 int global_node_diff[NR_VM_NODE_STAT_ITEMS] = { 0, }; 815 int changes = 0; 816 817 for_each_populated_zone(zone) { 818 struct per_cpu_zonestat __percpu *pzstats = zone->per_cpu_zonestats; 819 struct per_cpu_pages __percpu *pcp = zone->per_cpu_pageset; 820 821 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) { 822 int v; 823 824 v = this_cpu_xchg(pzstats->vm_stat_diff[i], 0); 825 if (v) { 826 827 atomic_long_add(v, &zone->vm_stat[i]); 828 global_zone_diff[i] += v; 829#ifdef CONFIG_NUMA 830 /* 3 seconds idle till flush */ 831 __this_cpu_write(pcp->expire, 3); 832#endif 833 } 834 } 835 836 if (do_pagesets) { 837 cond_resched(); 838 839 changes += decay_pcp_high(zone, this_cpu_ptr(pcp)); 840#ifdef CONFIG_NUMA 841 /* 842 * Deal with draining the remote pageset of this 843 * processor 844 * 845 * Check if there are pages remaining in this pageset 846 * if not then there is nothing to expire. 847 */ 848 if (!__this_cpu_read(pcp->expire) || 849 !__this_cpu_read(pcp->count)) 850 continue; 851 852 /* 853 * We never drain zones local to this processor. 854 */ 855 if (zone_to_nid(zone) == numa_node_id()) { 856 __this_cpu_write(pcp->expire, 0); 857 continue; 858 } 859 860 if (__this_cpu_dec_return(pcp->expire)) { 861 changes++; 862 continue; 863 } 864 865 if (__this_cpu_read(pcp->count)) { 866 drain_zone_pages(zone, this_cpu_ptr(pcp)); 867 changes++; 868 } 869#endif 870 } 871 } 872 873 for_each_online_pgdat(pgdat) { 874 struct per_cpu_nodestat __percpu *p = pgdat->per_cpu_nodestats; 875 876 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) { 877 int v; 878 879 v = this_cpu_xchg(p->vm_node_stat_diff[i], 0); 880 if (v) { 881 atomic_long_add(v, &pgdat->vm_stat[i]); 882 global_node_diff[i] += v; 883 } 884 } 885 } 886 887 changes += fold_diff(global_zone_diff, global_node_diff); 888 return changes; 889} 890 891/* 892 * Fold the data for an offline cpu into the global array. 893 * There cannot be any access by the offline cpu and therefore 894 * synchronization is simplified. 895 */ 896void cpu_vm_stats_fold(int cpu) 897{ 898 struct pglist_data *pgdat; 899 struct zone *zone; 900 int i; 901 int global_zone_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, }; 902 int global_node_diff[NR_VM_NODE_STAT_ITEMS] = { 0, }; 903 904 for_each_populated_zone(zone) { 905 struct per_cpu_zonestat *pzstats; 906 907 pzstats = per_cpu_ptr(zone->per_cpu_zonestats, cpu); 908 909 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) { 910 if (pzstats->vm_stat_diff[i]) { 911 int v; 912 913 v = pzstats->vm_stat_diff[i]; 914 pzstats->vm_stat_diff[i] = 0; 915 atomic_long_add(v, &zone->vm_stat[i]); 916 global_zone_diff[i] += v; 917 } 918 } 919#ifdef CONFIG_NUMA 920 for (i = 0; i < NR_VM_NUMA_EVENT_ITEMS; i++) { 921 if (pzstats->vm_numa_event[i]) { 922 unsigned long v; 923 924 v = pzstats->vm_numa_event[i]; 925 pzstats->vm_numa_event[i] = 0; 926 zone_numa_event_add(v, zone, i); 927 } 928 } 929#endif 930 } 931 932 for_each_online_pgdat(pgdat) { 933 struct per_cpu_nodestat *p; 934 935 p = per_cpu_ptr(pgdat->per_cpu_nodestats, cpu); 936 937 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) 938 if (p->vm_node_stat_diff[i]) { 939 int v; 940 941 v = p->vm_node_stat_diff[i]; 942 p->vm_node_stat_diff[i] = 0; 943 atomic_long_add(v, &pgdat->vm_stat[i]); 944 global_node_diff[i] += v; 945 } 946 } 947 948 fold_diff(global_zone_diff, global_node_diff); 949} 950 951/* 952 * this is only called if !populated_zone(zone), which implies no other users of 953 * pset->vm_stat_diff[] exist. 954 */ 955void drain_zonestat(struct zone *zone, struct per_cpu_zonestat *pzstats) 956{ 957 unsigned long v; 958 int i; 959 960 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) { 961 if (pzstats->vm_stat_diff[i]) { 962 v = pzstats->vm_stat_diff[i]; 963 pzstats->vm_stat_diff[i] = 0; 964 zone_page_state_add(v, zone, i); 965 } 966 } 967 968#ifdef CONFIG_NUMA 969 for (i = 0; i < NR_VM_NUMA_EVENT_ITEMS; i++) { 970 if (pzstats->vm_numa_event[i]) { 971 v = pzstats->vm_numa_event[i]; 972 pzstats->vm_numa_event[i] = 0; 973 zone_numa_event_add(v, zone, i); 974 } 975 } 976#endif 977} 978#endif 979 980#ifdef CONFIG_NUMA 981/* 982 * Determine the per node value of a stat item. This function 983 * is called frequently in a NUMA machine, so try to be as 984 * frugal as possible. 985 */ 986unsigned long sum_zone_node_page_state(int node, 987 enum zone_stat_item item) 988{ 989 struct zone *zones = NODE_DATA(node)->node_zones; 990 int i; 991 unsigned long count = 0; 992 993 for (i = 0; i < MAX_NR_ZONES; i++) 994 count += zone_page_state(zones + i, item); 995 996 return count; 997} 998 999/* Determine the per node value of a numa stat item. */ 1000unsigned long sum_zone_numa_event_state(int node, 1001 enum numa_stat_item item) 1002{ 1003 struct zone *zones = NODE_DATA(node)->node_zones; 1004 unsigned long count = 0; 1005 int i; 1006 1007 for (i = 0; i < MAX_NR_ZONES; i++) 1008 count += zone_numa_event_state(zones + i, item); 1009 1010 return count; 1011} 1012 1013/* 1014 * Determine the per node value of a stat item. 1015 */ 1016unsigned long node_page_state_pages(struct pglist_data *pgdat, 1017 enum node_stat_item item) 1018{ 1019 long x = atomic_long_read(&pgdat->vm_stat[item]); 1020#ifdef CONFIG_SMP 1021 if (x < 0) 1022 x = 0; 1023#endif 1024 return x; 1025} 1026 1027unsigned long node_page_state(struct pglist_data *pgdat, 1028 enum node_stat_item item) 1029{ 1030 VM_WARN_ON_ONCE(vmstat_item_in_bytes(item)); 1031 1032 return node_page_state_pages(pgdat, item); 1033} 1034#endif 1035 1036#ifdef CONFIG_COMPACTION 1037 1038struct contig_page_info { 1039 unsigned long free_pages; 1040 unsigned long free_blocks_total; 1041 unsigned long free_blocks_suitable; 1042}; 1043 1044/* 1045 * Calculate the number of free pages in a zone, how many contiguous 1046 * pages are free and how many are large enough to satisfy an allocation of 1047 * the target size. Note that this function makes no attempt to estimate 1048 * how many suitable free blocks there *might* be if MOVABLE pages were 1049 * migrated. Calculating that is possible, but expensive and can be 1050 * figured out from userspace 1051 */ 1052static void fill_contig_page_info(struct zone *zone, 1053 unsigned int suitable_order, 1054 struct contig_page_info *info) 1055{ 1056 unsigned int order; 1057 1058 info->free_pages = 0; 1059 info->free_blocks_total = 0; 1060 info->free_blocks_suitable = 0; 1061 1062 for (order = 0; order < NR_PAGE_ORDERS; order++) { 1063 unsigned long blocks; 1064 1065 /* 1066 * Count number of free blocks. 1067 * 1068 * Access to nr_free is lockless as nr_free is used only for 1069 * diagnostic purposes. Use data_race to avoid KCSAN warning. 1070 */ 1071 blocks = data_race(zone->free_area[order].nr_free); 1072 info->free_blocks_total += blocks; 1073 1074 /* Count free base pages */ 1075 info->free_pages += blocks << order; 1076 1077 /* Count the suitable free blocks */ 1078 if (order >= suitable_order) 1079 info->free_blocks_suitable += blocks << 1080 (order - suitable_order); 1081 } 1082} 1083 1084/* 1085 * A fragmentation index only makes sense if an allocation of a requested 1086 * size would fail. If that is true, the fragmentation index indicates 1087 * whether external fragmentation or a lack of memory was the problem. 1088 * The value can be used to determine if page reclaim or compaction 1089 * should be used 1090 */ 1091static int __fragmentation_index(unsigned int order, struct contig_page_info *info) 1092{ 1093 unsigned long requested = 1UL << order; 1094 1095 if (WARN_ON_ONCE(order > MAX_PAGE_ORDER)) 1096 return 0; 1097 1098 if (!info->free_blocks_total) 1099 return 0; 1100 1101 /* Fragmentation index only makes sense when a request would fail */ 1102 if (info->free_blocks_suitable) 1103 return -1000; 1104 1105 /* 1106 * Index is between 0 and 1 so return within 3 decimal places 1107 * 1108 * 0 => allocation would fail due to lack of memory 1109 * 1 => allocation would fail due to fragmentation 1110 */ 1111 return 1000 - div_u64( (1000+(div_u64(info->free_pages * 1000ULL, requested))), info->free_blocks_total); 1112} 1113 1114/* 1115 * Calculates external fragmentation within a zone wrt the given order. 1116 * It is defined as the percentage of pages found in blocks of size 1117 * less than 1 << order. It returns values in range [0, 100]. 1118 */ 1119unsigned int extfrag_for_order(struct zone *zone, unsigned int order) 1120{ 1121 struct contig_page_info info; 1122 1123 fill_contig_page_info(zone, order, &info); 1124 if (info.free_pages == 0) 1125 return 0; 1126 1127 return div_u64((info.free_pages - 1128 (info.free_blocks_suitable << order)) * 100, 1129 info.free_pages); 1130} 1131 1132/* Same as __fragmentation index but allocs contig_page_info on stack */ 1133int fragmentation_index(struct zone *zone, unsigned int order) 1134{ 1135 struct contig_page_info info; 1136 1137 fill_contig_page_info(zone, order, &info); 1138 return __fragmentation_index(order, &info); 1139} 1140#endif 1141 1142#if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS) || \ 1143 defined(CONFIG_NUMA) || defined(CONFIG_MEMCG) 1144#ifdef CONFIG_ZONE_DMA 1145#define TEXT_FOR_DMA(xx) xx "_dma", 1146#else 1147#define TEXT_FOR_DMA(xx) 1148#endif 1149 1150#ifdef CONFIG_ZONE_DMA32 1151#define TEXT_FOR_DMA32(xx) xx "_dma32", 1152#else 1153#define TEXT_FOR_DMA32(xx) 1154#endif 1155 1156#ifdef CONFIG_HIGHMEM 1157#define TEXT_FOR_HIGHMEM(xx) xx "_high", 1158#else 1159#define TEXT_FOR_HIGHMEM(xx) 1160#endif 1161 1162#ifdef CONFIG_ZONE_DEVICE 1163#define TEXT_FOR_DEVICE(xx) xx "_device", 1164#else 1165#define TEXT_FOR_DEVICE(xx) 1166#endif 1167 1168#define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \ 1169 TEXT_FOR_HIGHMEM(xx) xx "_movable", \ 1170 TEXT_FOR_DEVICE(xx) 1171 1172const char * const vmstat_text[] = { 1173 /* enum zone_stat_item counters */ 1174 "nr_free_pages", 1175 "nr_zone_inactive_anon", 1176 "nr_zone_active_anon", 1177 "nr_zone_inactive_file", 1178 "nr_zone_active_file", 1179 "nr_zone_unevictable", 1180 "nr_zone_write_pending", 1181 "nr_mlock", 1182 "nr_bounce", 1183#if IS_ENABLED(CONFIG_ZSMALLOC) 1184 "nr_zspages", 1185#endif 1186 "nr_free_cma", 1187#ifdef CONFIG_UNACCEPTED_MEMORY 1188 "nr_unaccepted", 1189#endif 1190 1191 /* enum numa_stat_item counters */ 1192#ifdef CONFIG_NUMA 1193 "numa_hit", 1194 "numa_miss", 1195 "numa_foreign", 1196 "numa_interleave", 1197 "numa_local", 1198 "numa_other", 1199#endif 1200 1201 /* enum node_stat_item counters */ 1202 "nr_inactive_anon", 1203 "nr_active_anon", 1204 "nr_inactive_file", 1205 "nr_active_file", 1206 "nr_unevictable", 1207 "nr_slab_reclaimable", 1208 "nr_slab_unreclaimable", 1209 "nr_isolated_anon", 1210 "nr_isolated_file", 1211 "workingset_nodes", 1212 "workingset_refault_anon", 1213 "workingset_refault_file", 1214 "workingset_activate_anon", 1215 "workingset_activate_file", 1216 "workingset_restore_anon", 1217 "workingset_restore_file", 1218 "workingset_nodereclaim", 1219 "nr_anon_pages", 1220 "nr_mapped", 1221 "nr_file_pages", 1222 "nr_dirty", 1223 "nr_writeback", 1224 "nr_writeback_temp", 1225 "nr_shmem", 1226 "nr_shmem_hugepages", 1227 "nr_shmem_pmdmapped", 1228 "nr_file_hugepages", 1229 "nr_file_pmdmapped", 1230 "nr_anon_transparent_hugepages", 1231 "nr_vmscan_write", 1232 "nr_vmscan_immediate_reclaim", 1233 "nr_dirtied", 1234 "nr_written", 1235 "nr_throttled_written", 1236 "nr_kernel_misc_reclaimable", 1237 "nr_foll_pin_acquired", 1238 "nr_foll_pin_released", 1239 "nr_kernel_stack", 1240#if IS_ENABLED(CONFIG_SHADOW_CALL_STACK) 1241 "nr_shadow_call_stack", 1242#endif 1243 "nr_page_table_pages", 1244 "nr_sec_page_table_pages", 1245#ifdef CONFIG_SWAP 1246 "nr_swapcached", 1247#endif 1248#ifdef CONFIG_NUMA_BALANCING 1249 "pgpromote_success", 1250 "pgpromote_candidate", 1251#endif 1252 "pgdemote_kswapd", 1253 "pgdemote_direct", 1254 "pgdemote_khugepaged", 1255 1256 /* enum writeback_stat_item counters */ 1257 "nr_dirty_threshold", 1258 "nr_dirty_background_threshold", 1259 1260#if defined(CONFIG_VM_EVENT_COUNTERS) || defined(CONFIG_MEMCG) 1261 /* enum vm_event_item counters */ 1262 "pgpgin", 1263 "pgpgout", 1264 "pswpin", 1265 "pswpout", 1266 1267 TEXTS_FOR_ZONES("pgalloc") 1268 TEXTS_FOR_ZONES("allocstall") 1269 TEXTS_FOR_ZONES("pgskip") 1270 1271 "pgfree", 1272 "pgactivate", 1273 "pgdeactivate", 1274 "pglazyfree", 1275 1276 "pgfault", 1277 "pgmajfault", 1278 "pglazyfreed", 1279 1280 "pgrefill", 1281 "pgreuse", 1282 "pgsteal_kswapd", 1283 "pgsteal_direct", 1284 "pgsteal_khugepaged", 1285 "pgscan_kswapd", 1286 "pgscan_direct", 1287 "pgscan_khugepaged", 1288 "pgscan_direct_throttle", 1289 "pgscan_anon", 1290 "pgscan_file", 1291 "pgsteal_anon", 1292 "pgsteal_file", 1293 1294#ifdef CONFIG_NUMA 1295 "zone_reclaim_failed", 1296#endif 1297 "pginodesteal", 1298 "slabs_scanned", 1299 "kswapd_inodesteal", 1300 "kswapd_low_wmark_hit_quickly", 1301 "kswapd_high_wmark_hit_quickly", 1302 "pageoutrun", 1303 1304 "pgrotated", 1305 1306 "drop_pagecache", 1307 "drop_slab", 1308 "oom_kill", 1309 1310#ifdef CONFIG_NUMA_BALANCING 1311 "numa_pte_updates", 1312 "numa_huge_pte_updates", 1313 "numa_hint_faults", 1314 "numa_hint_faults_local", 1315 "numa_pages_migrated", 1316#endif 1317#ifdef CONFIG_MIGRATION 1318 "pgmigrate_success", 1319 "pgmigrate_fail", 1320 "thp_migration_success", 1321 "thp_migration_fail", 1322 "thp_migration_split", 1323#endif 1324#ifdef CONFIG_COMPACTION 1325 "compact_migrate_scanned", 1326 "compact_free_scanned", 1327 "compact_isolated", 1328 "compact_stall", 1329 "compact_fail", 1330 "compact_success", 1331 "compact_daemon_wake", 1332 "compact_daemon_migrate_scanned", 1333 "compact_daemon_free_scanned", 1334#endif 1335 1336#ifdef CONFIG_HUGETLB_PAGE 1337 "htlb_buddy_alloc_success", 1338 "htlb_buddy_alloc_fail", 1339#endif 1340#ifdef CONFIG_CMA 1341 "cma_alloc_success", 1342 "cma_alloc_fail", 1343#endif 1344 "unevictable_pgs_culled", 1345 "unevictable_pgs_scanned", 1346 "unevictable_pgs_rescued", 1347 "unevictable_pgs_mlocked", 1348 "unevictable_pgs_munlocked", 1349 "unevictable_pgs_cleared", 1350 "unevictable_pgs_stranded", 1351 1352#ifdef CONFIG_TRANSPARENT_HUGEPAGE 1353 "thp_fault_alloc", 1354 "thp_fault_fallback", 1355 "thp_fault_fallback_charge", 1356 "thp_collapse_alloc", 1357 "thp_collapse_alloc_failed", 1358 "thp_file_alloc", 1359 "thp_file_fallback", 1360 "thp_file_fallback_charge", 1361 "thp_file_mapped", 1362 "thp_split_page", 1363 "thp_split_page_failed", 1364 "thp_deferred_split_page", 1365 "thp_split_pmd", 1366 "thp_scan_exceed_none_pte", 1367 "thp_scan_exceed_swap_pte", 1368 "thp_scan_exceed_share_pte", 1369#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD 1370 "thp_split_pud", 1371#endif 1372 "thp_zero_page_alloc", 1373 "thp_zero_page_alloc_failed", 1374 "thp_swpout", 1375 "thp_swpout_fallback", 1376#endif 1377#ifdef CONFIG_MEMORY_BALLOON 1378 "balloon_inflate", 1379 "balloon_deflate", 1380#ifdef CONFIG_BALLOON_COMPACTION 1381 "balloon_migrate", 1382#endif 1383#endif /* CONFIG_MEMORY_BALLOON */ 1384#ifdef CONFIG_DEBUG_TLBFLUSH 1385 "nr_tlb_remote_flush", 1386 "nr_tlb_remote_flush_received", 1387 "nr_tlb_local_flush_all", 1388 "nr_tlb_local_flush_one", 1389#endif /* CONFIG_DEBUG_TLBFLUSH */ 1390 1391#ifdef CONFIG_SWAP 1392 "swap_ra", 1393 "swap_ra_hit", 1394#ifdef CONFIG_KSM 1395 "ksm_swpin_copy", 1396#endif 1397#endif 1398#ifdef CONFIG_KSM 1399 "cow_ksm", 1400#endif 1401#ifdef CONFIG_ZSWAP 1402 "zswpin", 1403 "zswpout", 1404 "zswpwb", 1405#endif 1406#ifdef CONFIG_X86 1407 "direct_map_level2_splits", 1408 "direct_map_level3_splits", 1409#endif 1410#ifdef CONFIG_PER_VMA_LOCK_STATS 1411 "vma_lock_success", 1412 "vma_lock_abort", 1413 "vma_lock_retry", 1414 "vma_lock_miss", 1415#endif 1416#endif /* CONFIG_VM_EVENT_COUNTERS || CONFIG_MEMCG */ 1417}; 1418#endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA || CONFIG_MEMCG */ 1419 1420#if (defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)) || \ 1421 defined(CONFIG_PROC_FS) 1422static void *frag_start(struct seq_file *m, loff_t *pos) 1423{ 1424 pg_data_t *pgdat; 1425 loff_t node = *pos; 1426 1427 for (pgdat = first_online_pgdat(); 1428 pgdat && node; 1429 pgdat = next_online_pgdat(pgdat)) 1430 --node; 1431 1432 return pgdat; 1433} 1434 1435static void *frag_next(struct seq_file *m, void *arg, loff_t *pos) 1436{ 1437 pg_data_t *pgdat = (pg_data_t *)arg; 1438 1439 (*pos)++; 1440 return next_online_pgdat(pgdat); 1441} 1442 1443static void frag_stop(struct seq_file *m, void *arg) 1444{ 1445} 1446 1447/* 1448 * Walk zones in a node and print using a callback. 1449 * If @assert_populated is true, only use callback for zones that are populated. 1450 */ 1451static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat, 1452 bool assert_populated, bool nolock, 1453 void (*print)(struct seq_file *m, pg_data_t *, struct zone *)) 1454{ 1455 struct zone *zone; 1456 struct zone *node_zones = pgdat->node_zones; 1457 unsigned long flags; 1458 1459 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) { 1460 if (assert_populated && !populated_zone(zone)) 1461 continue; 1462 1463 if (!nolock) 1464 spin_lock_irqsave(&zone->lock, flags); 1465 print(m, pgdat, zone); 1466 if (!nolock) 1467 spin_unlock_irqrestore(&zone->lock, flags); 1468 } 1469} 1470#endif 1471 1472#ifdef CONFIG_PROC_FS 1473static void frag_show_print(struct seq_file *m, pg_data_t *pgdat, 1474 struct zone *zone) 1475{ 1476 int order; 1477 1478 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name); 1479 for (order = 0; order < NR_PAGE_ORDERS; ++order) 1480 /* 1481 * Access to nr_free is lockless as nr_free is used only for 1482 * printing purposes. Use data_race to avoid KCSAN warning. 1483 */ 1484 seq_printf(m, "%6lu ", data_race(zone->free_area[order].nr_free)); 1485 seq_putc(m, '\n'); 1486} 1487 1488/* 1489 * This walks the free areas for each zone. 1490 */ 1491static int frag_show(struct seq_file *m, void *arg) 1492{ 1493 pg_data_t *pgdat = (pg_data_t *)arg; 1494 walk_zones_in_node(m, pgdat, true, false, frag_show_print); 1495 return 0; 1496} 1497 1498static void pagetypeinfo_showfree_print(struct seq_file *m, 1499 pg_data_t *pgdat, struct zone *zone) 1500{ 1501 int order, mtype; 1502 1503 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) { 1504 seq_printf(m, "Node %4d, zone %8s, type %12s ", 1505 pgdat->node_id, 1506 zone->name, 1507 migratetype_names[mtype]); 1508 for (order = 0; order < NR_PAGE_ORDERS; ++order) { 1509 unsigned long freecount = 0; 1510 struct free_area *area; 1511 struct list_head *curr; 1512 bool overflow = false; 1513 1514 area = &(zone->free_area[order]); 1515 1516 list_for_each(curr, &area->free_list[mtype]) { 1517 /* 1518 * Cap the free_list iteration because it might 1519 * be really large and we are under a spinlock 1520 * so a long time spent here could trigger a 1521 * hard lockup detector. Anyway this is a 1522 * debugging tool so knowing there is a handful 1523 * of pages of this order should be more than 1524 * sufficient. 1525 */ 1526 if (++freecount >= 100000) { 1527 overflow = true; 1528 break; 1529 } 1530 } 1531 seq_printf(m, "%s%6lu ", overflow ? ">" : "", freecount); 1532 spin_unlock_irq(&zone->lock); 1533 cond_resched(); 1534 spin_lock_irq(&zone->lock); 1535 } 1536 seq_putc(m, '\n'); 1537 } 1538} 1539 1540/* Print out the free pages at each order for each migatetype */ 1541static void pagetypeinfo_showfree(struct seq_file *m, void *arg) 1542{ 1543 int order; 1544 pg_data_t *pgdat = (pg_data_t *)arg; 1545 1546 /* Print header */ 1547 seq_printf(m, "%-43s ", "Free pages count per migrate type at order"); 1548 for (order = 0; order < NR_PAGE_ORDERS; ++order) 1549 seq_printf(m, "%6d ", order); 1550 seq_putc(m, '\n'); 1551 1552 walk_zones_in_node(m, pgdat, true, false, pagetypeinfo_showfree_print); 1553} 1554 1555static void pagetypeinfo_showblockcount_print(struct seq_file *m, 1556 pg_data_t *pgdat, struct zone *zone) 1557{ 1558 int mtype; 1559 unsigned long pfn; 1560 unsigned long start_pfn = zone->zone_start_pfn; 1561 unsigned long end_pfn = zone_end_pfn(zone); 1562 unsigned long count[MIGRATE_TYPES] = { 0, }; 1563 1564 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) { 1565 struct page *page; 1566 1567 page = pfn_to_online_page(pfn); 1568 if (!page) 1569 continue; 1570 1571 if (page_zone(page) != zone) 1572 continue; 1573 1574 mtype = get_pageblock_migratetype(page); 1575 1576 if (mtype < MIGRATE_TYPES) 1577 count[mtype]++; 1578 } 1579 1580 /* Print counts */ 1581 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name); 1582 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) 1583 seq_printf(m, "%12lu ", count[mtype]); 1584 seq_putc(m, '\n'); 1585} 1586 1587/* Print out the number of pageblocks for each migratetype */ 1588static void pagetypeinfo_showblockcount(struct seq_file *m, void *arg) 1589{ 1590 int mtype; 1591 pg_data_t *pgdat = (pg_data_t *)arg; 1592 1593 seq_printf(m, "\n%-23s", "Number of blocks type "); 1594 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) 1595 seq_printf(m, "%12s ", migratetype_names[mtype]); 1596 seq_putc(m, '\n'); 1597 walk_zones_in_node(m, pgdat, true, false, 1598 pagetypeinfo_showblockcount_print); 1599} 1600 1601/* 1602 * Print out the number of pageblocks for each migratetype that contain pages 1603 * of other types. This gives an indication of how well fallbacks are being 1604 * contained by rmqueue_fallback(). It requires information from PAGE_OWNER 1605 * to determine what is going on 1606 */ 1607static void pagetypeinfo_showmixedcount(struct seq_file *m, pg_data_t *pgdat) 1608{ 1609#ifdef CONFIG_PAGE_OWNER 1610 int mtype; 1611 1612 if (!static_branch_unlikely(&page_owner_inited)) 1613 return; 1614 1615 drain_all_pages(NULL); 1616 1617 seq_printf(m, "\n%-23s", "Number of mixed blocks "); 1618 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) 1619 seq_printf(m, "%12s ", migratetype_names[mtype]); 1620 seq_putc(m, '\n'); 1621 1622 walk_zones_in_node(m, pgdat, true, true, 1623 pagetypeinfo_showmixedcount_print); 1624#endif /* CONFIG_PAGE_OWNER */ 1625} 1626 1627/* 1628 * This prints out statistics in relation to grouping pages by mobility. 1629 * It is expensive to collect so do not constantly read the file. 1630 */ 1631static int pagetypeinfo_show(struct seq_file *m, void *arg) 1632{ 1633 pg_data_t *pgdat = (pg_data_t *)arg; 1634 1635 /* check memoryless node */ 1636 if (!node_state(pgdat->node_id, N_MEMORY)) 1637 return 0; 1638 1639 seq_printf(m, "Page block order: %d\n", pageblock_order); 1640 seq_printf(m, "Pages per block: %lu\n", pageblock_nr_pages); 1641 seq_putc(m, '\n'); 1642 pagetypeinfo_showfree(m, pgdat); 1643 pagetypeinfo_showblockcount(m, pgdat); 1644 pagetypeinfo_showmixedcount(m, pgdat); 1645 1646 return 0; 1647} 1648 1649static const struct seq_operations fragmentation_op = { 1650 .start = frag_start, 1651 .next = frag_next, 1652 .stop = frag_stop, 1653 .show = frag_show, 1654}; 1655 1656static const struct seq_operations pagetypeinfo_op = { 1657 .start = frag_start, 1658 .next = frag_next, 1659 .stop = frag_stop, 1660 .show = pagetypeinfo_show, 1661}; 1662 1663static bool is_zone_first_populated(pg_data_t *pgdat, struct zone *zone) 1664{ 1665 int zid; 1666 1667 for (zid = 0; zid < MAX_NR_ZONES; zid++) { 1668 struct zone *compare = &pgdat->node_zones[zid]; 1669 1670 if (populated_zone(compare)) 1671 return zone == compare; 1672 } 1673 1674 return false; 1675} 1676 1677static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat, 1678 struct zone *zone) 1679{ 1680 int i; 1681 seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name); 1682 if (is_zone_first_populated(pgdat, zone)) { 1683 seq_printf(m, "\n per-node stats"); 1684 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) { 1685 unsigned long pages = node_page_state_pages(pgdat, i); 1686 1687 if (vmstat_item_print_in_thp(i)) 1688 pages /= HPAGE_PMD_NR; 1689 seq_printf(m, "\n %-12s %lu", node_stat_name(i), 1690 pages); 1691 } 1692 } 1693 seq_printf(m, 1694 "\n pages free %lu" 1695 "\n boost %lu" 1696 "\n min %lu" 1697 "\n low %lu" 1698 "\n high %lu" 1699 "\n spanned %lu" 1700 "\n present %lu" 1701 "\n managed %lu" 1702 "\n cma %lu", 1703 zone_page_state(zone, NR_FREE_PAGES), 1704 zone->watermark_boost, 1705 min_wmark_pages(zone), 1706 low_wmark_pages(zone), 1707 high_wmark_pages(zone), 1708 zone->spanned_pages, 1709 zone->present_pages, 1710 zone_managed_pages(zone), 1711 zone_cma_pages(zone)); 1712 1713 seq_printf(m, 1714 "\n protection: (%ld", 1715 zone->lowmem_reserve[0]); 1716 for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++) 1717 seq_printf(m, ", %ld", zone->lowmem_reserve[i]); 1718 seq_putc(m, ')'); 1719 1720 /* If unpopulated, no other information is useful */ 1721 if (!populated_zone(zone)) { 1722 seq_putc(m, '\n'); 1723 return; 1724 } 1725 1726 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) 1727 seq_printf(m, "\n %-12s %lu", zone_stat_name(i), 1728 zone_page_state(zone, i)); 1729 1730#ifdef CONFIG_NUMA 1731 for (i = 0; i < NR_VM_NUMA_EVENT_ITEMS; i++) 1732 seq_printf(m, "\n %-12s %lu", numa_stat_name(i), 1733 zone_numa_event_state(zone, i)); 1734#endif 1735 1736 seq_printf(m, "\n pagesets"); 1737 for_each_online_cpu(i) { 1738 struct per_cpu_pages *pcp; 1739 struct per_cpu_zonestat __maybe_unused *pzstats; 1740 1741 pcp = per_cpu_ptr(zone->per_cpu_pageset, i); 1742 seq_printf(m, 1743 "\n cpu: %i" 1744 "\n count: %i" 1745 "\n high: %i" 1746 "\n batch: %i", 1747 i, 1748 pcp->count, 1749 pcp->high, 1750 pcp->batch); 1751#ifdef CONFIG_SMP 1752 pzstats = per_cpu_ptr(zone->per_cpu_zonestats, i); 1753 seq_printf(m, "\n vm stats threshold: %d", 1754 pzstats->stat_threshold); 1755#endif 1756 } 1757 seq_printf(m, 1758 "\n node_unreclaimable: %u" 1759 "\n start_pfn: %lu", 1760 pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES, 1761 zone->zone_start_pfn); 1762 seq_putc(m, '\n'); 1763} 1764 1765/* 1766 * Output information about zones in @pgdat. All zones are printed regardless 1767 * of whether they are populated or not: lowmem_reserve_ratio operates on the 1768 * set of all zones and userspace would not be aware of such zones if they are 1769 * suppressed here (zoneinfo displays the effect of lowmem_reserve_ratio). 1770 */ 1771static int zoneinfo_show(struct seq_file *m, void *arg) 1772{ 1773 pg_data_t *pgdat = (pg_data_t *)arg; 1774 walk_zones_in_node(m, pgdat, false, false, zoneinfo_show_print); 1775 return 0; 1776} 1777 1778static const struct seq_operations zoneinfo_op = { 1779 .start = frag_start, /* iterate over all zones. The same as in 1780 * fragmentation. */ 1781 .next = frag_next, 1782 .stop = frag_stop, 1783 .show = zoneinfo_show, 1784}; 1785 1786#define NR_VMSTAT_ITEMS (NR_VM_ZONE_STAT_ITEMS + \ 1787 NR_VM_NUMA_EVENT_ITEMS + \ 1788 NR_VM_NODE_STAT_ITEMS + \ 1789 NR_VM_WRITEBACK_STAT_ITEMS + \ 1790 (IS_ENABLED(CONFIG_VM_EVENT_COUNTERS) ? \ 1791 NR_VM_EVENT_ITEMS : 0)) 1792 1793static void *vmstat_start(struct seq_file *m, loff_t *pos) 1794{ 1795 unsigned long *v; 1796 int i; 1797 1798 if (*pos >= NR_VMSTAT_ITEMS) 1799 return NULL; 1800 1801 BUILD_BUG_ON(ARRAY_SIZE(vmstat_text) < NR_VMSTAT_ITEMS); 1802 fold_vm_numa_events(); 1803 v = kmalloc_array(NR_VMSTAT_ITEMS, sizeof(unsigned long), GFP_KERNEL); 1804 m->private = v; 1805 if (!v) 1806 return ERR_PTR(-ENOMEM); 1807 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) 1808 v[i] = global_zone_page_state(i); 1809 v += NR_VM_ZONE_STAT_ITEMS; 1810 1811#ifdef CONFIG_NUMA 1812 for (i = 0; i < NR_VM_NUMA_EVENT_ITEMS; i++) 1813 v[i] = global_numa_event_state(i); 1814 v += NR_VM_NUMA_EVENT_ITEMS; 1815#endif 1816 1817 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) { 1818 v[i] = global_node_page_state_pages(i); 1819 if (vmstat_item_print_in_thp(i)) 1820 v[i] /= HPAGE_PMD_NR; 1821 } 1822 v += NR_VM_NODE_STAT_ITEMS; 1823 1824 global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD, 1825 v + NR_DIRTY_THRESHOLD); 1826 v += NR_VM_WRITEBACK_STAT_ITEMS; 1827 1828#ifdef CONFIG_VM_EVENT_COUNTERS 1829 all_vm_events(v); 1830 v[PGPGIN] /= 2; /* sectors -> kbytes */ 1831 v[PGPGOUT] /= 2; 1832#endif 1833 return (unsigned long *)m->private + *pos; 1834} 1835 1836static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos) 1837{ 1838 (*pos)++; 1839 if (*pos >= NR_VMSTAT_ITEMS) 1840 return NULL; 1841 return (unsigned long *)m->private + *pos; 1842} 1843 1844static int vmstat_show(struct seq_file *m, void *arg) 1845{ 1846 unsigned long *l = arg; 1847 unsigned long off = l - (unsigned long *)m->private; 1848 1849 seq_puts(m, vmstat_text[off]); 1850 seq_put_decimal_ull(m, " ", *l); 1851 seq_putc(m, '\n'); 1852 1853 if (off == NR_VMSTAT_ITEMS - 1) { 1854 /* 1855 * We've come to the end - add any deprecated counters to avoid 1856 * breaking userspace which might depend on them being present. 1857 */ 1858 seq_puts(m, "nr_unstable 0\n"); 1859 } 1860 return 0; 1861} 1862 1863static void vmstat_stop(struct seq_file *m, void *arg) 1864{ 1865 kfree(m->private); 1866 m->private = NULL; 1867} 1868 1869static const struct seq_operations vmstat_op = { 1870 .start = vmstat_start, 1871 .next = vmstat_next, 1872 .stop = vmstat_stop, 1873 .show = vmstat_show, 1874}; 1875#endif /* CONFIG_PROC_FS */ 1876 1877#ifdef CONFIG_SMP 1878static DEFINE_PER_CPU(struct delayed_work, vmstat_work); 1879int sysctl_stat_interval __read_mostly = HZ; 1880 1881#ifdef CONFIG_PROC_FS 1882static void refresh_vm_stats(struct work_struct *work) 1883{ 1884 refresh_cpu_vm_stats(true); 1885} 1886 1887int vmstat_refresh(struct ctl_table *table, int write, 1888 void *buffer, size_t *lenp, loff_t *ppos) 1889{ 1890 long val; 1891 int err; 1892 int i; 1893 1894 /* 1895 * The regular update, every sysctl_stat_interval, may come later 1896 * than expected: leaving a significant amount in per_cpu buckets. 1897 * This is particularly misleading when checking a quantity of HUGE 1898 * pages, immediately after running a test. /proc/sys/vm/stat_refresh, 1899 * which can equally be echo'ed to or cat'ted from (by root), 1900 * can be used to update the stats just before reading them. 1901 * 1902 * Oh, and since global_zone_page_state() etc. are so careful to hide 1903 * transiently negative values, report an error here if any of 1904 * the stats is negative, so we know to go looking for imbalance. 1905 */ 1906 err = schedule_on_each_cpu(refresh_vm_stats); 1907 if (err) 1908 return err; 1909 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) { 1910 /* 1911 * Skip checking stats known to go negative occasionally. 1912 */ 1913 switch (i) { 1914 case NR_ZONE_WRITE_PENDING: 1915 case NR_FREE_CMA_PAGES: 1916 continue; 1917 } 1918 val = atomic_long_read(&vm_zone_stat[i]); 1919 if (val < 0) { 1920 pr_warn("%s: %s %ld\n", 1921 __func__, zone_stat_name(i), val); 1922 } 1923 } 1924 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) { 1925 /* 1926 * Skip checking stats known to go negative occasionally. 1927 */ 1928 switch (i) { 1929 case NR_WRITEBACK: 1930 continue; 1931 } 1932 val = atomic_long_read(&vm_node_stat[i]); 1933 if (val < 0) { 1934 pr_warn("%s: %s %ld\n", 1935 __func__, node_stat_name(i), val); 1936 } 1937 } 1938 if (write) 1939 *ppos += *lenp; 1940 else 1941 *lenp = 0; 1942 return 0; 1943} 1944#endif /* CONFIG_PROC_FS */ 1945 1946static void vmstat_update(struct work_struct *w) 1947{ 1948 if (refresh_cpu_vm_stats(true)) { 1949 /* 1950 * Counters were updated so we expect more updates 1951 * to occur in the future. Keep on running the 1952 * update worker thread. 1953 */ 1954 queue_delayed_work_on(smp_processor_id(), mm_percpu_wq, 1955 this_cpu_ptr(&vmstat_work), 1956 round_jiffies_relative(sysctl_stat_interval)); 1957 } 1958} 1959 1960/* 1961 * Check if the diffs for a certain cpu indicate that 1962 * an update is needed. 1963 */ 1964static bool need_update(int cpu) 1965{ 1966 pg_data_t *last_pgdat = NULL; 1967 struct zone *zone; 1968 1969 for_each_populated_zone(zone) { 1970 struct per_cpu_zonestat *pzstats = per_cpu_ptr(zone->per_cpu_zonestats, cpu); 1971 struct per_cpu_nodestat *n; 1972 1973 /* 1974 * The fast way of checking if there are any vmstat diffs. 1975 */ 1976 if (memchr_inv(pzstats->vm_stat_diff, 0, sizeof(pzstats->vm_stat_diff))) 1977 return true; 1978 1979 if (last_pgdat == zone->zone_pgdat) 1980 continue; 1981 last_pgdat = zone->zone_pgdat; 1982 n = per_cpu_ptr(zone->zone_pgdat->per_cpu_nodestats, cpu); 1983 if (memchr_inv(n->vm_node_stat_diff, 0, sizeof(n->vm_node_stat_diff))) 1984 return true; 1985 } 1986 return false; 1987} 1988 1989/* 1990 * Switch off vmstat processing and then fold all the remaining differentials 1991 * until the diffs stay at zero. The function is used by NOHZ and can only be 1992 * invoked when tick processing is not active. 1993 */ 1994void quiet_vmstat(void) 1995{ 1996 if (system_state != SYSTEM_RUNNING) 1997 return; 1998 1999 if (!delayed_work_pending(this_cpu_ptr(&vmstat_work))) 2000 return; 2001 2002 if (!need_update(smp_processor_id())) 2003 return; 2004 2005 /* 2006 * Just refresh counters and do not care about the pending delayed 2007 * vmstat_update. It doesn't fire that often to matter and canceling 2008 * it would be too expensive from this path. 2009 * vmstat_shepherd will take care about that for us. 2010 */ 2011 refresh_cpu_vm_stats(false); 2012} 2013 2014/* 2015 * Shepherd worker thread that checks the 2016 * differentials of processors that have their worker 2017 * threads for vm statistics updates disabled because of 2018 * inactivity. 2019 */ 2020static void vmstat_shepherd(struct work_struct *w); 2021 2022static DECLARE_DEFERRABLE_WORK(shepherd, vmstat_shepherd); 2023 2024static void vmstat_shepherd(struct work_struct *w) 2025{ 2026 int cpu; 2027 2028 cpus_read_lock(); 2029 /* Check processors whose vmstat worker threads have been disabled */ 2030 for_each_online_cpu(cpu) { 2031 struct delayed_work *dw = &per_cpu(vmstat_work, cpu); 2032 2033 /* 2034 * In kernel users of vmstat counters either require the precise value and 2035 * they are using zone_page_state_snapshot interface or they can live with 2036 * an imprecision as the regular flushing can happen at arbitrary time and 2037 * cumulative error can grow (see calculate_normal_threshold). 2038 * 2039 * From that POV the regular flushing can be postponed for CPUs that have 2040 * been isolated from the kernel interference without critical 2041 * infrastructure ever noticing. Skip regular flushing from vmstat_shepherd 2042 * for all isolated CPUs to avoid interference with the isolated workload. 2043 */ 2044 if (cpu_is_isolated(cpu)) 2045 continue; 2046 2047 if (!delayed_work_pending(dw) && need_update(cpu)) 2048 queue_delayed_work_on(cpu, mm_percpu_wq, dw, 0); 2049 2050 cond_resched(); 2051 } 2052 cpus_read_unlock(); 2053 2054 schedule_delayed_work(&shepherd, 2055 round_jiffies_relative(sysctl_stat_interval)); 2056} 2057 2058static void __init start_shepherd_timer(void) 2059{ 2060 int cpu; 2061 2062 for_each_possible_cpu(cpu) 2063 INIT_DEFERRABLE_WORK(per_cpu_ptr(&vmstat_work, cpu), 2064 vmstat_update); 2065 2066 schedule_delayed_work(&shepherd, 2067 round_jiffies_relative(sysctl_stat_interval)); 2068} 2069 2070static void __init init_cpu_node_state(void) 2071{ 2072 int node; 2073 2074 for_each_online_node(node) { 2075 if (!cpumask_empty(cpumask_of_node(node))) 2076 node_set_state(node, N_CPU); 2077 } 2078} 2079 2080static int vmstat_cpu_online(unsigned int cpu) 2081{ 2082 refresh_zone_stat_thresholds(); 2083 2084 if (!node_state(cpu_to_node(cpu), N_CPU)) { 2085 node_set_state(cpu_to_node(cpu), N_CPU); 2086 } 2087 2088 return 0; 2089} 2090 2091static int vmstat_cpu_down_prep(unsigned int cpu) 2092{ 2093 cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu)); 2094 return 0; 2095} 2096 2097static int vmstat_cpu_dead(unsigned int cpu) 2098{ 2099 const struct cpumask *node_cpus; 2100 int node; 2101 2102 node = cpu_to_node(cpu); 2103 2104 refresh_zone_stat_thresholds(); 2105 node_cpus = cpumask_of_node(node); 2106 if (!cpumask_empty(node_cpus)) 2107 return 0; 2108 2109 node_clear_state(node, N_CPU); 2110 2111 return 0; 2112} 2113 2114#endif 2115 2116struct workqueue_struct *mm_percpu_wq; 2117 2118void __init init_mm_internals(void) 2119{ 2120 int ret __maybe_unused; 2121 2122 mm_percpu_wq = alloc_workqueue("mm_percpu_wq", WQ_MEM_RECLAIM, 0); 2123 2124#ifdef CONFIG_SMP 2125 ret = cpuhp_setup_state_nocalls(CPUHP_MM_VMSTAT_DEAD, "mm/vmstat:dead", 2126 NULL, vmstat_cpu_dead); 2127 if (ret < 0) 2128 pr_err("vmstat: failed to register 'dead' hotplug state\n"); 2129 2130 ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "mm/vmstat:online", 2131 vmstat_cpu_online, 2132 vmstat_cpu_down_prep); 2133 if (ret < 0) 2134 pr_err("vmstat: failed to register 'online' hotplug state\n"); 2135 2136 cpus_read_lock(); 2137 init_cpu_node_state(); 2138 cpus_read_unlock(); 2139 2140 start_shepherd_timer(); 2141#endif 2142#ifdef CONFIG_PROC_FS 2143 proc_create_seq("buddyinfo", 0444, NULL, &fragmentation_op); 2144 proc_create_seq("pagetypeinfo", 0400, NULL, &pagetypeinfo_op); 2145 proc_create_seq("vmstat", 0444, NULL, &vmstat_op); 2146 proc_create_seq("zoneinfo", 0444, NULL, &zoneinfo_op); 2147#endif 2148} 2149 2150#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION) 2151 2152/* 2153 * Return an index indicating how much of the available free memory is 2154 * unusable for an allocation of the requested size. 2155 */ 2156static int unusable_free_index(unsigned int order, 2157 struct contig_page_info *info) 2158{ 2159 /* No free memory is interpreted as all free memory is unusable */ 2160 if (info->free_pages == 0) 2161 return 1000; 2162 2163 /* 2164 * Index should be a value between 0 and 1. Return a value to 3 2165 * decimal places. 2166 * 2167 * 0 => no fragmentation 2168 * 1 => high fragmentation 2169 */ 2170 return div_u64((info->free_pages - (info->free_blocks_suitable << order)) * 1000ULL, info->free_pages); 2171 2172} 2173 2174static void unusable_show_print(struct seq_file *m, 2175 pg_data_t *pgdat, struct zone *zone) 2176{ 2177 unsigned int order; 2178 int index; 2179 struct contig_page_info info; 2180 2181 seq_printf(m, "Node %d, zone %8s ", 2182 pgdat->node_id, 2183 zone->name); 2184 for (order = 0; order < NR_PAGE_ORDERS; ++order) { 2185 fill_contig_page_info(zone, order, &info); 2186 index = unusable_free_index(order, &info); 2187 seq_printf(m, "%d.%03d ", index / 1000, index % 1000); 2188 } 2189 2190 seq_putc(m, '\n'); 2191} 2192 2193/* 2194 * Display unusable free space index 2195 * 2196 * The unusable free space index measures how much of the available free 2197 * memory cannot be used to satisfy an allocation of a given size and is a 2198 * value between 0 and 1. The higher the value, the more of free memory is 2199 * unusable and by implication, the worse the external fragmentation is. This 2200 * can be expressed as a percentage by multiplying by 100. 2201 */ 2202static int unusable_show(struct seq_file *m, void *arg) 2203{ 2204 pg_data_t *pgdat = (pg_data_t *)arg; 2205 2206 /* check memoryless node */ 2207 if (!node_state(pgdat->node_id, N_MEMORY)) 2208 return 0; 2209 2210 walk_zones_in_node(m, pgdat, true, false, unusable_show_print); 2211 2212 return 0; 2213} 2214 2215static const struct seq_operations unusable_sops = { 2216 .start = frag_start, 2217 .next = frag_next, 2218 .stop = frag_stop, 2219 .show = unusable_show, 2220}; 2221 2222DEFINE_SEQ_ATTRIBUTE(unusable); 2223 2224static void extfrag_show_print(struct seq_file *m, 2225 pg_data_t *pgdat, struct zone *zone) 2226{ 2227 unsigned int order; 2228 int index; 2229 2230 /* Alloc on stack as interrupts are disabled for zone walk */ 2231 struct contig_page_info info; 2232 2233 seq_printf(m, "Node %d, zone %8s ", 2234 pgdat->node_id, 2235 zone->name); 2236 for (order = 0; order < NR_PAGE_ORDERS; ++order) { 2237 fill_contig_page_info(zone, order, &info); 2238 index = __fragmentation_index(order, &info); 2239 seq_printf(m, "%2d.%03d ", index / 1000, index % 1000); 2240 } 2241 2242 seq_putc(m, '\n'); 2243} 2244 2245/* 2246 * Display fragmentation index for orders that allocations would fail for 2247 */ 2248static int extfrag_show(struct seq_file *m, void *arg) 2249{ 2250 pg_data_t *pgdat = (pg_data_t *)arg; 2251 2252 walk_zones_in_node(m, pgdat, true, false, extfrag_show_print); 2253 2254 return 0; 2255} 2256 2257static const struct seq_operations extfrag_sops = { 2258 .start = frag_start, 2259 .next = frag_next, 2260 .stop = frag_stop, 2261 .show = extfrag_show, 2262}; 2263 2264DEFINE_SEQ_ATTRIBUTE(extfrag); 2265 2266static int __init extfrag_debug_init(void) 2267{ 2268 struct dentry *extfrag_debug_root; 2269 2270 extfrag_debug_root = debugfs_create_dir("extfrag", NULL); 2271 2272 debugfs_create_file("unusable_index", 0444, extfrag_debug_root, NULL, 2273 &unusable_fops); 2274 2275 debugfs_create_file("extfrag_index", 0444, extfrag_debug_root, NULL, 2276 &extfrag_fops); 2277 2278 return 0; 2279} 2280 2281module_init(extfrag_debug_init); 2282#endif 2283