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