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_KSM 1397 "cow_ksm", 1398 #endif 1399 #ifdef CONFIG_ZSWAP 1400 "zswpin", 1401 "zswpout", 1402 #endif 1403 #ifdef CONFIG_X86 1404 "direct_map_level2_splits", 1405 "direct_map_level3_splits", 1406 #endif 1407 #endif /* CONFIG_VM_EVENT_COUNTERS || CONFIG_MEMCG */ 1408 }; 1409 #endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA || CONFIG_MEMCG */ 1410 1411 #if (defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)) || \ 1412 defined(CONFIG_PROC_FS) 1413 static void *frag_start(struct seq_file *m, loff_t *pos) 1414 { 1415 pg_data_t *pgdat; 1416 loff_t node = *pos; 1417 1418 for (pgdat = first_online_pgdat(); 1419 pgdat && node; 1420 pgdat = next_online_pgdat(pgdat)) 1421 --node; 1422 1423 return pgdat; 1424 } 1425 1426 static void *frag_next(struct seq_file *m, void *arg, loff_t *pos) 1427 { 1428 pg_data_t *pgdat = (pg_data_t *)arg; 1429 1430 (*pos)++; 1431 return next_online_pgdat(pgdat); 1432 } 1433 1434 static void frag_stop(struct seq_file *m, void *arg) 1435 { 1436 } 1437 1438 /* 1439 * Walk zones in a node and print using a callback. 1440 * If @assert_populated is true, only use callback for zones that are populated. 1441 */ 1442 static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat, 1443 bool assert_populated, bool nolock, 1444 void (*print)(struct seq_file *m, pg_data_t *, struct zone *)) 1445 { 1446 struct zone *zone; 1447 struct zone *node_zones = pgdat->node_zones; 1448 unsigned long flags; 1449 1450 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) { 1451 if (assert_populated && !populated_zone(zone)) 1452 continue; 1453 1454 if (!nolock) 1455 spin_lock_irqsave(&zone->lock, flags); 1456 print(m, pgdat, zone); 1457 if (!nolock) 1458 spin_unlock_irqrestore(&zone->lock, flags); 1459 } 1460 } 1461 #endif 1462 1463 #ifdef CONFIG_PROC_FS 1464 static void frag_show_print(struct seq_file *m, pg_data_t *pgdat, 1465 struct zone *zone) 1466 { 1467 int order; 1468 1469 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name); 1470 for (order = 0; order < MAX_ORDER; ++order) 1471 /* 1472 * Access to nr_free is lockless as nr_free is used only for 1473 * printing purposes. Use data_race to avoid KCSAN warning. 1474 */ 1475 seq_printf(m, "%6lu ", data_race(zone->free_area[order].nr_free)); 1476 seq_putc(m, '\n'); 1477 } 1478 1479 /* 1480 * This walks the free areas for each zone. 1481 */ 1482 static int frag_show(struct seq_file *m, void *arg) 1483 { 1484 pg_data_t *pgdat = (pg_data_t *)arg; 1485 walk_zones_in_node(m, pgdat, true, false, frag_show_print); 1486 return 0; 1487 } 1488 1489 static void pagetypeinfo_showfree_print(struct seq_file *m, 1490 pg_data_t *pgdat, struct zone *zone) 1491 { 1492 int order, mtype; 1493 1494 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) { 1495 seq_printf(m, "Node %4d, zone %8s, type %12s ", 1496 pgdat->node_id, 1497 zone->name, 1498 migratetype_names[mtype]); 1499 for (order = 0; order < MAX_ORDER; ++order) { 1500 unsigned long freecount = 0; 1501 struct free_area *area; 1502 struct list_head *curr; 1503 bool overflow = false; 1504 1505 area = &(zone->free_area[order]); 1506 1507 list_for_each(curr, &area->free_list[mtype]) { 1508 /* 1509 * Cap the free_list iteration because it might 1510 * be really large and we are under a spinlock 1511 * so a long time spent here could trigger a 1512 * hard lockup detector. Anyway this is a 1513 * debugging tool so knowing there is a handful 1514 * of pages of this order should be more than 1515 * sufficient. 1516 */ 1517 if (++freecount >= 100000) { 1518 overflow = true; 1519 break; 1520 } 1521 } 1522 seq_printf(m, "%s%6lu ", overflow ? ">" : "", freecount); 1523 spin_unlock_irq(&zone->lock); 1524 cond_resched(); 1525 spin_lock_irq(&zone->lock); 1526 } 1527 seq_putc(m, '\n'); 1528 } 1529 } 1530 1531 /* Print out the free pages at each order for each migatetype */ 1532 static void pagetypeinfo_showfree(struct seq_file *m, void *arg) 1533 { 1534 int order; 1535 pg_data_t *pgdat = (pg_data_t *)arg; 1536 1537 /* Print header */ 1538 seq_printf(m, "%-43s ", "Free pages count per migrate type at order"); 1539 for (order = 0; order < MAX_ORDER; ++order) 1540 seq_printf(m, "%6d ", order); 1541 seq_putc(m, '\n'); 1542 1543 walk_zones_in_node(m, pgdat, true, false, pagetypeinfo_showfree_print); 1544 } 1545 1546 static void pagetypeinfo_showblockcount_print(struct seq_file *m, 1547 pg_data_t *pgdat, struct zone *zone) 1548 { 1549 int mtype; 1550 unsigned long pfn; 1551 unsigned long start_pfn = zone->zone_start_pfn; 1552 unsigned long end_pfn = zone_end_pfn(zone); 1553 unsigned long count[MIGRATE_TYPES] = { 0, }; 1554 1555 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) { 1556 struct page *page; 1557 1558 page = pfn_to_online_page(pfn); 1559 if (!page) 1560 continue; 1561 1562 if (page_zone(page) != zone) 1563 continue; 1564 1565 mtype = get_pageblock_migratetype(page); 1566 1567 if (mtype < MIGRATE_TYPES) 1568 count[mtype]++; 1569 } 1570 1571 /* Print counts */ 1572 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name); 1573 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) 1574 seq_printf(m, "%12lu ", count[mtype]); 1575 seq_putc(m, '\n'); 1576 } 1577 1578 /* Print out the number of pageblocks for each migratetype */ 1579 static void pagetypeinfo_showblockcount(struct seq_file *m, void *arg) 1580 { 1581 int mtype; 1582 pg_data_t *pgdat = (pg_data_t *)arg; 1583 1584 seq_printf(m, "\n%-23s", "Number of blocks type "); 1585 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) 1586 seq_printf(m, "%12s ", migratetype_names[mtype]); 1587 seq_putc(m, '\n'); 1588 walk_zones_in_node(m, pgdat, true, false, 1589 pagetypeinfo_showblockcount_print); 1590 } 1591 1592 /* 1593 * Print out the number of pageblocks for each migratetype that contain pages 1594 * of other types. This gives an indication of how well fallbacks are being 1595 * contained by rmqueue_fallback(). It requires information from PAGE_OWNER 1596 * to determine what is going on 1597 */ 1598 static void pagetypeinfo_showmixedcount(struct seq_file *m, pg_data_t *pgdat) 1599 { 1600 #ifdef CONFIG_PAGE_OWNER 1601 int mtype; 1602 1603 if (!static_branch_unlikely(&page_owner_inited)) 1604 return; 1605 1606 drain_all_pages(NULL); 1607 1608 seq_printf(m, "\n%-23s", "Number of mixed blocks "); 1609 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) 1610 seq_printf(m, "%12s ", migratetype_names[mtype]); 1611 seq_putc(m, '\n'); 1612 1613 walk_zones_in_node(m, pgdat, true, true, 1614 pagetypeinfo_showmixedcount_print); 1615 #endif /* CONFIG_PAGE_OWNER */ 1616 } 1617 1618 /* 1619 * This prints out statistics in relation to grouping pages by mobility. 1620 * It is expensive to collect so do not constantly read the file. 1621 */ 1622 static int pagetypeinfo_show(struct seq_file *m, void *arg) 1623 { 1624 pg_data_t *pgdat = (pg_data_t *)arg; 1625 1626 /* check memoryless node */ 1627 if (!node_state(pgdat->node_id, N_MEMORY)) 1628 return 0; 1629 1630 seq_printf(m, "Page block order: %d\n", pageblock_order); 1631 seq_printf(m, "Pages per block: %lu\n", pageblock_nr_pages); 1632 seq_putc(m, '\n'); 1633 pagetypeinfo_showfree(m, pgdat); 1634 pagetypeinfo_showblockcount(m, pgdat); 1635 pagetypeinfo_showmixedcount(m, pgdat); 1636 1637 return 0; 1638 } 1639 1640 static const struct seq_operations fragmentation_op = { 1641 .start = frag_start, 1642 .next = frag_next, 1643 .stop = frag_stop, 1644 .show = frag_show, 1645 }; 1646 1647 static const struct seq_operations pagetypeinfo_op = { 1648 .start = frag_start, 1649 .next = frag_next, 1650 .stop = frag_stop, 1651 .show = pagetypeinfo_show, 1652 }; 1653 1654 static bool is_zone_first_populated(pg_data_t *pgdat, struct zone *zone) 1655 { 1656 int zid; 1657 1658 for (zid = 0; zid < MAX_NR_ZONES; zid++) { 1659 struct zone *compare = &pgdat->node_zones[zid]; 1660 1661 if (populated_zone(compare)) 1662 return zone == compare; 1663 } 1664 1665 return false; 1666 } 1667 1668 static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat, 1669 struct zone *zone) 1670 { 1671 int i; 1672 seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name); 1673 if (is_zone_first_populated(pgdat, zone)) { 1674 seq_printf(m, "\n per-node stats"); 1675 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) { 1676 unsigned long pages = node_page_state_pages(pgdat, i); 1677 1678 if (vmstat_item_print_in_thp(i)) 1679 pages /= HPAGE_PMD_NR; 1680 seq_printf(m, "\n %-12s %lu", node_stat_name(i), 1681 pages); 1682 } 1683 } 1684 seq_printf(m, 1685 "\n pages free %lu" 1686 "\n boost %lu" 1687 "\n min %lu" 1688 "\n low %lu" 1689 "\n high %lu" 1690 "\n spanned %lu" 1691 "\n present %lu" 1692 "\n managed %lu" 1693 "\n cma %lu", 1694 zone_page_state(zone, NR_FREE_PAGES), 1695 zone->watermark_boost, 1696 min_wmark_pages(zone), 1697 low_wmark_pages(zone), 1698 high_wmark_pages(zone), 1699 zone->spanned_pages, 1700 zone->present_pages, 1701 zone_managed_pages(zone), 1702 zone_cma_pages(zone)); 1703 1704 seq_printf(m, 1705 "\n protection: (%ld", 1706 zone->lowmem_reserve[0]); 1707 for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++) 1708 seq_printf(m, ", %ld", zone->lowmem_reserve[i]); 1709 seq_putc(m, ')'); 1710 1711 /* If unpopulated, no other information is useful */ 1712 if (!populated_zone(zone)) { 1713 seq_putc(m, '\n'); 1714 return; 1715 } 1716 1717 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) 1718 seq_printf(m, "\n %-12s %lu", zone_stat_name(i), 1719 zone_page_state(zone, i)); 1720 1721 #ifdef CONFIG_NUMA 1722 for (i = 0; i < NR_VM_NUMA_EVENT_ITEMS; i++) 1723 seq_printf(m, "\n %-12s %lu", numa_stat_name(i), 1724 zone_numa_event_state(zone, i)); 1725 #endif 1726 1727 seq_printf(m, "\n pagesets"); 1728 for_each_online_cpu(i) { 1729 struct per_cpu_pages *pcp; 1730 struct per_cpu_zonestat __maybe_unused *pzstats; 1731 1732 pcp = per_cpu_ptr(zone->per_cpu_pageset, i); 1733 seq_printf(m, 1734 "\n cpu: %i" 1735 "\n count: %i" 1736 "\n high: %i" 1737 "\n batch: %i", 1738 i, 1739 pcp->count, 1740 pcp->high, 1741 pcp->batch); 1742 #ifdef CONFIG_SMP 1743 pzstats = per_cpu_ptr(zone->per_cpu_zonestats, i); 1744 seq_printf(m, "\n vm stats threshold: %d", 1745 pzstats->stat_threshold); 1746 #endif 1747 } 1748 seq_printf(m, 1749 "\n node_unreclaimable: %u" 1750 "\n start_pfn: %lu", 1751 pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES, 1752 zone->zone_start_pfn); 1753 seq_putc(m, '\n'); 1754 } 1755 1756 /* 1757 * Output information about zones in @pgdat. All zones are printed regardless 1758 * of whether they are populated or not: lowmem_reserve_ratio operates on the 1759 * set of all zones and userspace would not be aware of such zones if they are 1760 * suppressed here (zoneinfo displays the effect of lowmem_reserve_ratio). 1761 */ 1762 static int zoneinfo_show(struct seq_file *m, void *arg) 1763 { 1764 pg_data_t *pgdat = (pg_data_t *)arg; 1765 walk_zones_in_node(m, pgdat, false, false, zoneinfo_show_print); 1766 return 0; 1767 } 1768 1769 static const struct seq_operations zoneinfo_op = { 1770 .start = frag_start, /* iterate over all zones. The same as in 1771 * fragmentation. */ 1772 .next = frag_next, 1773 .stop = frag_stop, 1774 .show = zoneinfo_show, 1775 }; 1776 1777 #define NR_VMSTAT_ITEMS (NR_VM_ZONE_STAT_ITEMS + \ 1778 NR_VM_NUMA_EVENT_ITEMS + \ 1779 NR_VM_NODE_STAT_ITEMS + \ 1780 NR_VM_WRITEBACK_STAT_ITEMS + \ 1781 (IS_ENABLED(CONFIG_VM_EVENT_COUNTERS) ? \ 1782 NR_VM_EVENT_ITEMS : 0)) 1783 1784 static void *vmstat_start(struct seq_file *m, loff_t *pos) 1785 { 1786 unsigned long *v; 1787 int i; 1788 1789 if (*pos >= NR_VMSTAT_ITEMS) 1790 return NULL; 1791 1792 BUILD_BUG_ON(ARRAY_SIZE(vmstat_text) < NR_VMSTAT_ITEMS); 1793 fold_vm_numa_events(); 1794 v = kmalloc_array(NR_VMSTAT_ITEMS, sizeof(unsigned long), GFP_KERNEL); 1795 m->private = v; 1796 if (!v) 1797 return ERR_PTR(-ENOMEM); 1798 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) 1799 v[i] = global_zone_page_state(i); 1800 v += NR_VM_ZONE_STAT_ITEMS; 1801 1802 #ifdef CONFIG_NUMA 1803 for (i = 0; i < NR_VM_NUMA_EVENT_ITEMS; i++) 1804 v[i] = global_numa_event_state(i); 1805 v += NR_VM_NUMA_EVENT_ITEMS; 1806 #endif 1807 1808 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) { 1809 v[i] = global_node_page_state_pages(i); 1810 if (vmstat_item_print_in_thp(i)) 1811 v[i] /= HPAGE_PMD_NR; 1812 } 1813 v += NR_VM_NODE_STAT_ITEMS; 1814 1815 global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD, 1816 v + NR_DIRTY_THRESHOLD); 1817 v += NR_VM_WRITEBACK_STAT_ITEMS; 1818 1819 #ifdef CONFIG_VM_EVENT_COUNTERS 1820 all_vm_events(v); 1821 v[PGPGIN] /= 2; /* sectors -> kbytes */ 1822 v[PGPGOUT] /= 2; 1823 #endif 1824 return (unsigned long *)m->private + *pos; 1825 } 1826 1827 static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos) 1828 { 1829 (*pos)++; 1830 if (*pos >= NR_VMSTAT_ITEMS) 1831 return NULL; 1832 return (unsigned long *)m->private + *pos; 1833 } 1834 1835 static int vmstat_show(struct seq_file *m, void *arg) 1836 { 1837 unsigned long *l = arg; 1838 unsigned long off = l - (unsigned long *)m->private; 1839 1840 seq_puts(m, vmstat_text[off]); 1841 seq_put_decimal_ull(m, " ", *l); 1842 seq_putc(m, '\n'); 1843 1844 if (off == NR_VMSTAT_ITEMS - 1) { 1845 /* 1846 * We've come to the end - add any deprecated counters to avoid 1847 * breaking userspace which might depend on them being present. 1848 */ 1849 seq_puts(m, "nr_unstable 0\n"); 1850 } 1851 return 0; 1852 } 1853 1854 static void vmstat_stop(struct seq_file *m, void *arg) 1855 { 1856 kfree(m->private); 1857 m->private = NULL; 1858 } 1859 1860 static const struct seq_operations vmstat_op = { 1861 .start = vmstat_start, 1862 .next = vmstat_next, 1863 .stop = vmstat_stop, 1864 .show = vmstat_show, 1865 }; 1866 #endif /* CONFIG_PROC_FS */ 1867 1868 #ifdef CONFIG_SMP 1869 static DEFINE_PER_CPU(struct delayed_work, vmstat_work); 1870 int sysctl_stat_interval __read_mostly = HZ; 1871 1872 #ifdef CONFIG_PROC_FS 1873 static void refresh_vm_stats(struct work_struct *work) 1874 { 1875 refresh_cpu_vm_stats(true); 1876 } 1877 1878 int vmstat_refresh(struct ctl_table *table, int write, 1879 void *buffer, size_t *lenp, loff_t *ppos) 1880 { 1881 long val; 1882 int err; 1883 int i; 1884 1885 /* 1886 * The regular update, every sysctl_stat_interval, may come later 1887 * than expected: leaving a significant amount in per_cpu buckets. 1888 * This is particularly misleading when checking a quantity of HUGE 1889 * pages, immediately after running a test. /proc/sys/vm/stat_refresh, 1890 * which can equally be echo'ed to or cat'ted from (by root), 1891 * can be used to update the stats just before reading them. 1892 * 1893 * Oh, and since global_zone_page_state() etc. are so careful to hide 1894 * transiently negative values, report an error here if any of 1895 * the stats is negative, so we know to go looking for imbalance. 1896 */ 1897 err = schedule_on_each_cpu(refresh_vm_stats); 1898 if (err) 1899 return err; 1900 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) { 1901 /* 1902 * Skip checking stats known to go negative occasionally. 1903 */ 1904 switch (i) { 1905 case NR_ZONE_WRITE_PENDING: 1906 case NR_FREE_CMA_PAGES: 1907 continue; 1908 } 1909 val = atomic_long_read(&vm_zone_stat[i]); 1910 if (val < 0) { 1911 pr_warn("%s: %s %ld\n", 1912 __func__, zone_stat_name(i), val); 1913 } 1914 } 1915 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) { 1916 /* 1917 * Skip checking stats known to go negative occasionally. 1918 */ 1919 switch (i) { 1920 case NR_WRITEBACK: 1921 continue; 1922 } 1923 val = atomic_long_read(&vm_node_stat[i]); 1924 if (val < 0) { 1925 pr_warn("%s: %s %ld\n", 1926 __func__, node_stat_name(i), val); 1927 } 1928 } 1929 if (write) 1930 *ppos += *lenp; 1931 else 1932 *lenp = 0; 1933 return 0; 1934 } 1935 #endif /* CONFIG_PROC_FS */ 1936 1937 static void vmstat_update(struct work_struct *w) 1938 { 1939 if (refresh_cpu_vm_stats(true)) { 1940 /* 1941 * Counters were updated so we expect more updates 1942 * to occur in the future. Keep on running the 1943 * update worker thread. 1944 */ 1945 queue_delayed_work_on(smp_processor_id(), mm_percpu_wq, 1946 this_cpu_ptr(&vmstat_work), 1947 round_jiffies_relative(sysctl_stat_interval)); 1948 } 1949 } 1950 1951 /* 1952 * Check if the diffs for a certain cpu indicate that 1953 * an update is needed. 1954 */ 1955 static bool need_update(int cpu) 1956 { 1957 pg_data_t *last_pgdat = NULL; 1958 struct zone *zone; 1959 1960 for_each_populated_zone(zone) { 1961 struct per_cpu_zonestat *pzstats = per_cpu_ptr(zone->per_cpu_zonestats, cpu); 1962 struct per_cpu_nodestat *n; 1963 1964 /* 1965 * The fast way of checking if there are any vmstat diffs. 1966 */ 1967 if (memchr_inv(pzstats->vm_stat_diff, 0, sizeof(pzstats->vm_stat_diff))) 1968 return true; 1969 1970 if (last_pgdat == zone->zone_pgdat) 1971 continue; 1972 last_pgdat = zone->zone_pgdat; 1973 n = per_cpu_ptr(zone->zone_pgdat->per_cpu_nodestats, cpu); 1974 if (memchr_inv(n->vm_node_stat_diff, 0, sizeof(n->vm_node_stat_diff))) 1975 return true; 1976 } 1977 return false; 1978 } 1979 1980 /* 1981 * Switch off vmstat processing and then fold all the remaining differentials 1982 * until the diffs stay at zero. The function is used by NOHZ and can only be 1983 * invoked when tick processing is not active. 1984 */ 1985 void quiet_vmstat(void) 1986 { 1987 if (system_state != SYSTEM_RUNNING) 1988 return; 1989 1990 if (!delayed_work_pending(this_cpu_ptr(&vmstat_work))) 1991 return; 1992 1993 if (!need_update(smp_processor_id())) 1994 return; 1995 1996 /* 1997 * Just refresh counters and do not care about the pending delayed 1998 * vmstat_update. It doesn't fire that often to matter and canceling 1999 * it would be too expensive from this path. 2000 * vmstat_shepherd will take care about that for us. 2001 */ 2002 refresh_cpu_vm_stats(false); 2003 } 2004 2005 /* 2006 * Shepherd worker thread that checks the 2007 * differentials of processors that have their worker 2008 * threads for vm statistics updates disabled because of 2009 * inactivity. 2010 */ 2011 static void vmstat_shepherd(struct work_struct *w); 2012 2013 static DECLARE_DEFERRABLE_WORK(shepherd, vmstat_shepherd); 2014 2015 static void vmstat_shepherd(struct work_struct *w) 2016 { 2017 int cpu; 2018 2019 cpus_read_lock(); 2020 /* Check processors whose vmstat worker threads have been disabled */ 2021 for_each_online_cpu(cpu) { 2022 struct delayed_work *dw = &per_cpu(vmstat_work, cpu); 2023 2024 if (!delayed_work_pending(dw) && need_update(cpu)) 2025 queue_delayed_work_on(cpu, mm_percpu_wq, dw, 0); 2026 2027 cond_resched(); 2028 } 2029 cpus_read_unlock(); 2030 2031 schedule_delayed_work(&shepherd, 2032 round_jiffies_relative(sysctl_stat_interval)); 2033 } 2034 2035 static void __init start_shepherd_timer(void) 2036 { 2037 int cpu; 2038 2039 for_each_possible_cpu(cpu) 2040 INIT_DEFERRABLE_WORK(per_cpu_ptr(&vmstat_work, cpu), 2041 vmstat_update); 2042 2043 schedule_delayed_work(&shepherd, 2044 round_jiffies_relative(sysctl_stat_interval)); 2045 } 2046 2047 static void __init init_cpu_node_state(void) 2048 { 2049 int node; 2050 2051 for_each_online_node(node) { 2052 if (cpumask_weight(cpumask_of_node(node)) > 0) 2053 node_set_state(node, N_CPU); 2054 } 2055 } 2056 2057 static int vmstat_cpu_online(unsigned int cpu) 2058 { 2059 refresh_zone_stat_thresholds(); 2060 2061 if (!node_state(cpu_to_node(cpu), N_CPU)) { 2062 node_set_state(cpu_to_node(cpu), N_CPU); 2063 set_migration_target_nodes(); 2064 } 2065 2066 return 0; 2067 } 2068 2069 static int vmstat_cpu_down_prep(unsigned int cpu) 2070 { 2071 cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu)); 2072 return 0; 2073 } 2074 2075 static int vmstat_cpu_dead(unsigned int cpu) 2076 { 2077 const struct cpumask *node_cpus; 2078 int node; 2079 2080 node = cpu_to_node(cpu); 2081 2082 refresh_zone_stat_thresholds(); 2083 node_cpus = cpumask_of_node(node); 2084 if (cpumask_weight(node_cpus) > 0) 2085 return 0; 2086 2087 node_clear_state(node, N_CPU); 2088 set_migration_target_nodes(); 2089 2090 return 0; 2091 } 2092 2093 #endif 2094 2095 struct workqueue_struct *mm_percpu_wq; 2096 2097 void __init init_mm_internals(void) 2098 { 2099 int ret __maybe_unused; 2100 2101 mm_percpu_wq = alloc_workqueue("mm_percpu_wq", WQ_MEM_RECLAIM, 0); 2102 2103 #ifdef CONFIG_SMP 2104 ret = cpuhp_setup_state_nocalls(CPUHP_MM_VMSTAT_DEAD, "mm/vmstat:dead", 2105 NULL, vmstat_cpu_dead); 2106 if (ret < 0) 2107 pr_err("vmstat: failed to register 'dead' hotplug state\n"); 2108 2109 ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "mm/vmstat:online", 2110 vmstat_cpu_online, 2111 vmstat_cpu_down_prep); 2112 if (ret < 0) 2113 pr_err("vmstat: failed to register 'online' hotplug state\n"); 2114 2115 cpus_read_lock(); 2116 init_cpu_node_state(); 2117 cpus_read_unlock(); 2118 2119 start_shepherd_timer(); 2120 #endif 2121 migrate_on_reclaim_init(); 2122 #ifdef CONFIG_PROC_FS 2123 proc_create_seq("buddyinfo", 0444, NULL, &fragmentation_op); 2124 proc_create_seq("pagetypeinfo", 0400, NULL, &pagetypeinfo_op); 2125 proc_create_seq("vmstat", 0444, NULL, &vmstat_op); 2126 proc_create_seq("zoneinfo", 0444, NULL, &zoneinfo_op); 2127 #endif 2128 } 2129 2130 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION) 2131 2132 /* 2133 * Return an index indicating how much of the available free memory is 2134 * unusable for an allocation of the requested size. 2135 */ 2136 static int unusable_free_index(unsigned int order, 2137 struct contig_page_info *info) 2138 { 2139 /* No free memory is interpreted as all free memory is unusable */ 2140 if (info->free_pages == 0) 2141 return 1000; 2142 2143 /* 2144 * Index should be a value between 0 and 1. Return a value to 3 2145 * decimal places. 2146 * 2147 * 0 => no fragmentation 2148 * 1 => high fragmentation 2149 */ 2150 return div_u64((info->free_pages - (info->free_blocks_suitable << order)) * 1000ULL, info->free_pages); 2151 2152 } 2153 2154 static void unusable_show_print(struct seq_file *m, 2155 pg_data_t *pgdat, struct zone *zone) 2156 { 2157 unsigned int order; 2158 int index; 2159 struct contig_page_info info; 2160 2161 seq_printf(m, "Node %d, zone %8s ", 2162 pgdat->node_id, 2163 zone->name); 2164 for (order = 0; order < MAX_ORDER; ++order) { 2165 fill_contig_page_info(zone, order, &info); 2166 index = unusable_free_index(order, &info); 2167 seq_printf(m, "%d.%03d ", index / 1000, index % 1000); 2168 } 2169 2170 seq_putc(m, '\n'); 2171 } 2172 2173 /* 2174 * Display unusable free space index 2175 * 2176 * The unusable free space index measures how much of the available free 2177 * memory cannot be used to satisfy an allocation of a given size and is a 2178 * value between 0 and 1. The higher the value, the more of free memory is 2179 * unusable and by implication, the worse the external fragmentation is. This 2180 * can be expressed as a percentage by multiplying by 100. 2181 */ 2182 static int unusable_show(struct seq_file *m, void *arg) 2183 { 2184 pg_data_t *pgdat = (pg_data_t *)arg; 2185 2186 /* check memoryless node */ 2187 if (!node_state(pgdat->node_id, N_MEMORY)) 2188 return 0; 2189 2190 walk_zones_in_node(m, pgdat, true, false, unusable_show_print); 2191 2192 return 0; 2193 } 2194 2195 static const struct seq_operations unusable_sops = { 2196 .start = frag_start, 2197 .next = frag_next, 2198 .stop = frag_stop, 2199 .show = unusable_show, 2200 }; 2201 2202 DEFINE_SEQ_ATTRIBUTE(unusable); 2203 2204 static void extfrag_show_print(struct seq_file *m, 2205 pg_data_t *pgdat, struct zone *zone) 2206 { 2207 unsigned int order; 2208 int index; 2209 2210 /* Alloc on stack as interrupts are disabled for zone walk */ 2211 struct contig_page_info info; 2212 2213 seq_printf(m, "Node %d, zone %8s ", 2214 pgdat->node_id, 2215 zone->name); 2216 for (order = 0; order < MAX_ORDER; ++order) { 2217 fill_contig_page_info(zone, order, &info); 2218 index = __fragmentation_index(order, &info); 2219 seq_printf(m, "%2d.%03d ", index / 1000, index % 1000); 2220 } 2221 2222 seq_putc(m, '\n'); 2223 } 2224 2225 /* 2226 * Display fragmentation index for orders that allocations would fail for 2227 */ 2228 static int extfrag_show(struct seq_file *m, void *arg) 2229 { 2230 pg_data_t *pgdat = (pg_data_t *)arg; 2231 2232 walk_zones_in_node(m, pgdat, true, false, extfrag_show_print); 2233 2234 return 0; 2235 } 2236 2237 static const struct seq_operations extfrag_sops = { 2238 .start = frag_start, 2239 .next = frag_next, 2240 .stop = frag_stop, 2241 .show = extfrag_show, 2242 }; 2243 2244 DEFINE_SEQ_ATTRIBUTE(extfrag); 2245 2246 static int __init extfrag_debug_init(void) 2247 { 2248 struct dentry *extfrag_debug_root; 2249 2250 extfrag_debug_root = debugfs_create_dir("extfrag", NULL); 2251 2252 debugfs_create_file("unusable_index", 0444, extfrag_debug_root, NULL, 2253 &unusable_fops); 2254 2255 debugfs_create_file("extfrag_index", 0444, extfrag_debug_root, NULL, 2256 &extfrag_fops); 2257 2258 return 0; 2259 } 2260 2261 module_init(extfrag_debug_init); 2262 #endif 2263