1/* 2 * linux/mm/vmstat.c 3 * 4 * Manages VM statistics 5 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds 6 * 7 * zoned VM statistics 8 * Copyright (C) 2006 Silicon Graphics, Inc., 9 * Christoph Lameter <christoph@lameter.com> 10 * Copyright (C) 2008-2014 Christoph Lameter 11 */ 12#include <linux/fs.h> 13#include <linux/mm.h> 14#include <linux/err.h> 15#include <linux/module.h> 16#include <linux/slab.h> 17#include <linux/cpu.h> 18#include <linux/cpumask.h> 19#include <linux/vmstat.h> 20#include <linux/proc_fs.h> 21#include <linux/seq_file.h> 22#include <linux/debugfs.h> 23#include <linux/sched.h> 24#include <linux/math64.h> 25#include <linux/writeback.h> 26#include <linux/compaction.h> 27#include <linux/mm_inline.h> 28#include <linux/page_ext.h> 29#include <linux/page_owner.h> 30 31#include "internal.h" 32 33#ifdef CONFIG_VM_EVENT_COUNTERS 34DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}}; 35EXPORT_PER_CPU_SYMBOL(vm_event_states); 36 37static void sum_vm_events(unsigned long *ret) 38{ 39 int cpu; 40 int i; 41 42 memset(ret, 0, NR_VM_EVENT_ITEMS * sizeof(unsigned long)); 43 44 for_each_online_cpu(cpu) { 45 struct vm_event_state *this = &per_cpu(vm_event_states, cpu); 46 47 for (i = 0; i < NR_VM_EVENT_ITEMS; i++) 48 ret[i] += this->event[i]; 49 } 50} 51 52/* 53 * Accumulate the vm event counters across all CPUs. 54 * The result is unavoidably approximate - it can change 55 * during and after execution of this function. 56*/ 57void all_vm_events(unsigned long *ret) 58{ 59 get_online_cpus(); 60 sum_vm_events(ret); 61 put_online_cpus(); 62} 63EXPORT_SYMBOL_GPL(all_vm_events); 64 65/* 66 * Fold the foreign cpu events into our own. 67 * 68 * This is adding to the events on one processor 69 * but keeps the global counts constant. 70 */ 71void vm_events_fold_cpu(int cpu) 72{ 73 struct vm_event_state *fold_state = &per_cpu(vm_event_states, cpu); 74 int i; 75 76 for (i = 0; i < NR_VM_EVENT_ITEMS; i++) { 77 count_vm_events(i, fold_state->event[i]); 78 fold_state->event[i] = 0; 79 } 80} 81 82#endif /* CONFIG_VM_EVENT_COUNTERS */ 83 84/* 85 * Manage combined zone based / global counters 86 * 87 * vm_stat contains the global counters 88 */ 89atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS] __cacheline_aligned_in_smp; 90EXPORT_SYMBOL(vm_stat); 91 92#ifdef CONFIG_SMP 93 94int calculate_pressure_threshold(struct zone *zone) 95{ 96 int threshold; 97 int watermark_distance; 98 99 /* 100 * As vmstats are not up to date, there is drift between the estimated 101 * and real values. For high thresholds and a high number of CPUs, it 102 * is possible for the min watermark to be breached while the estimated 103 * value looks fine. The pressure threshold is a reduced value such 104 * that even the maximum amount of drift will not accidentally breach 105 * the min watermark 106 */ 107 watermark_distance = low_wmark_pages(zone) - min_wmark_pages(zone); 108 threshold = max(1, (int)(watermark_distance / num_online_cpus())); 109 110 /* 111 * Maximum threshold is 125 112 */ 113 threshold = min(125, threshold); 114 115 return threshold; 116} 117 118int calculate_normal_threshold(struct zone *zone) 119{ 120 int threshold; 121 int mem; /* memory in 128 MB units */ 122 123 /* 124 * The threshold scales with the number of processors and the amount 125 * of memory per zone. More memory means that we can defer updates for 126 * longer, more processors could lead to more contention. 127 * fls() is used to have a cheap way of logarithmic scaling. 128 * 129 * Some sample thresholds: 130 * 131 * Threshold Processors (fls) Zonesize fls(mem+1) 132 * ------------------------------------------------------------------ 133 * 8 1 1 0.9-1 GB 4 134 * 16 2 2 0.9-1 GB 4 135 * 20 2 2 1-2 GB 5 136 * 24 2 2 2-4 GB 6 137 * 28 2 2 4-8 GB 7 138 * 32 2 2 8-16 GB 8 139 * 4 2 2 <128M 1 140 * 30 4 3 2-4 GB 5 141 * 48 4 3 8-16 GB 8 142 * 32 8 4 1-2 GB 4 143 * 32 8 4 0.9-1GB 4 144 * 10 16 5 <128M 1 145 * 40 16 5 900M 4 146 * 70 64 7 2-4 GB 5 147 * 84 64 7 4-8 GB 6 148 * 108 512 9 4-8 GB 6 149 * 125 1024 10 8-16 GB 8 150 * 125 1024 10 16-32 GB 9 151 */ 152 153 mem = zone->managed_pages >> (27 - PAGE_SHIFT); 154 155 threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem)); 156 157 /* 158 * Maximum threshold is 125 159 */ 160 threshold = min(125, threshold); 161 162 return threshold; 163} 164 165/* 166 * Refresh the thresholds for each zone. 167 */ 168void refresh_zone_stat_thresholds(void) 169{ 170 struct zone *zone; 171 int cpu; 172 int threshold; 173 174 for_each_populated_zone(zone) { 175 unsigned long max_drift, tolerate_drift; 176 177 threshold = calculate_normal_threshold(zone); 178 179 for_each_online_cpu(cpu) 180 per_cpu_ptr(zone->pageset, cpu)->stat_threshold 181 = threshold; 182 183 /* 184 * Only set percpu_drift_mark if there is a danger that 185 * NR_FREE_PAGES reports the low watermark is ok when in fact 186 * the min watermark could be breached by an allocation 187 */ 188 tolerate_drift = low_wmark_pages(zone) - min_wmark_pages(zone); 189 max_drift = num_online_cpus() * threshold; 190 if (max_drift > tolerate_drift) 191 zone->percpu_drift_mark = high_wmark_pages(zone) + 192 max_drift; 193 } 194} 195 196void set_pgdat_percpu_threshold(pg_data_t *pgdat, 197 int (*calculate_pressure)(struct zone *)) 198{ 199 struct zone *zone; 200 int cpu; 201 int threshold; 202 int i; 203 204 for (i = 0; i < pgdat->nr_zones; i++) { 205 zone = &pgdat->node_zones[i]; 206 if (!zone->percpu_drift_mark) 207 continue; 208 209 threshold = (*calculate_pressure)(zone); 210 for_each_online_cpu(cpu) 211 per_cpu_ptr(zone->pageset, cpu)->stat_threshold 212 = threshold; 213 } 214} 215 216/* 217 * For use when we know that interrupts are disabled, 218 * or when we know that preemption is disabled and that 219 * particular counter cannot be updated from interrupt context. 220 */ 221void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item, 222 int delta) 223{ 224 struct per_cpu_pageset __percpu *pcp = zone->pageset; 225 s8 __percpu *p = pcp->vm_stat_diff + item; 226 long x; 227 long t; 228 229 x = delta + __this_cpu_read(*p); 230 231 t = __this_cpu_read(pcp->stat_threshold); 232 233 if (unlikely(x > t || x < -t)) { 234 zone_page_state_add(x, zone, item); 235 x = 0; 236 } 237 __this_cpu_write(*p, x); 238} 239EXPORT_SYMBOL(__mod_zone_page_state); 240 241/* 242 * Optimized increment and decrement functions. 243 * 244 * These are only for a single page and therefore can take a struct page * 245 * argument instead of struct zone *. This allows the inclusion of the code 246 * generated for page_zone(page) into the optimized functions. 247 * 248 * No overflow check is necessary and therefore the differential can be 249 * incremented or decremented in place which may allow the compilers to 250 * generate better code. 251 * The increment or decrement is known and therefore one boundary check can 252 * be omitted. 253 * 254 * NOTE: These functions are very performance sensitive. Change only 255 * with care. 256 * 257 * Some processors have inc/dec instructions that are atomic vs an interrupt. 258 * However, the code must first determine the differential location in a zone 259 * based on the processor number and then inc/dec the counter. There is no 260 * guarantee without disabling preemption that the processor will not change 261 * in between and therefore the atomicity vs. interrupt cannot be exploited 262 * in a useful way here. 263 */ 264void __inc_zone_state(struct zone *zone, enum zone_stat_item item) 265{ 266 struct per_cpu_pageset __percpu *pcp = zone->pageset; 267 s8 __percpu *p = pcp->vm_stat_diff + item; 268 s8 v, t; 269 270 v = __this_cpu_inc_return(*p); 271 t = __this_cpu_read(pcp->stat_threshold); 272 if (unlikely(v > t)) { 273 s8 overstep = t >> 1; 274 275 zone_page_state_add(v + overstep, zone, item); 276 __this_cpu_write(*p, -overstep); 277 } 278} 279 280void __inc_zone_page_state(struct page *page, enum zone_stat_item item) 281{ 282 __inc_zone_state(page_zone(page), item); 283} 284EXPORT_SYMBOL(__inc_zone_page_state); 285 286void __dec_zone_state(struct zone *zone, enum zone_stat_item item) 287{ 288 struct per_cpu_pageset __percpu *pcp = zone->pageset; 289 s8 __percpu *p = pcp->vm_stat_diff + item; 290 s8 v, t; 291 292 v = __this_cpu_dec_return(*p); 293 t = __this_cpu_read(pcp->stat_threshold); 294 if (unlikely(v < - t)) { 295 s8 overstep = t >> 1; 296 297 zone_page_state_add(v - overstep, zone, item); 298 __this_cpu_write(*p, overstep); 299 } 300} 301 302void __dec_zone_page_state(struct page *page, enum zone_stat_item item) 303{ 304 __dec_zone_state(page_zone(page), item); 305} 306EXPORT_SYMBOL(__dec_zone_page_state); 307 308#ifdef CONFIG_HAVE_CMPXCHG_LOCAL 309/* 310 * If we have cmpxchg_local support then we do not need to incur the overhead 311 * that comes with local_irq_save/restore if we use this_cpu_cmpxchg. 312 * 313 * mod_state() modifies the zone counter state through atomic per cpu 314 * operations. 315 * 316 * Overstep mode specifies how overstep should handled: 317 * 0 No overstepping 318 * 1 Overstepping half of threshold 319 * -1 Overstepping minus half of threshold 320*/ 321static inline void mod_state(struct zone *zone, 322 enum zone_stat_item item, int delta, int overstep_mode) 323{ 324 struct per_cpu_pageset __percpu *pcp = zone->pageset; 325 s8 __percpu *p = pcp->vm_stat_diff + item; 326 long o, n, t, z; 327 328 do { 329 z = 0; /* overflow to zone counters */ 330 331 /* 332 * The fetching of the stat_threshold is racy. We may apply 333 * a counter threshold to the wrong the cpu if we get 334 * rescheduled while executing here. However, the next 335 * counter update will apply the threshold again and 336 * therefore bring the counter under the threshold again. 337 * 338 * Most of the time the thresholds are the same anyways 339 * for all cpus in a zone. 340 */ 341 t = this_cpu_read(pcp->stat_threshold); 342 343 o = this_cpu_read(*p); 344 n = delta + o; 345 346 if (n > t || n < -t) { 347 int os = overstep_mode * (t >> 1) ; 348 349 /* Overflow must be added to zone counters */ 350 z = n + os; 351 n = -os; 352 } 353 } while (this_cpu_cmpxchg(*p, o, n) != o); 354 355 if (z) 356 zone_page_state_add(z, zone, item); 357} 358 359void mod_zone_page_state(struct zone *zone, enum zone_stat_item item, 360 int delta) 361{ 362 mod_state(zone, item, delta, 0); 363} 364EXPORT_SYMBOL(mod_zone_page_state); 365 366void inc_zone_state(struct zone *zone, enum zone_stat_item item) 367{ 368 mod_state(zone, item, 1, 1); 369} 370 371void inc_zone_page_state(struct page *page, enum zone_stat_item item) 372{ 373 mod_state(page_zone(page), item, 1, 1); 374} 375EXPORT_SYMBOL(inc_zone_page_state); 376 377void dec_zone_page_state(struct page *page, enum zone_stat_item item) 378{ 379 mod_state(page_zone(page), item, -1, -1); 380} 381EXPORT_SYMBOL(dec_zone_page_state); 382#else 383/* 384 * Use interrupt disable to serialize counter updates 385 */ 386void mod_zone_page_state(struct zone *zone, enum zone_stat_item item, 387 int delta) 388{ 389 unsigned long flags; 390 391 local_irq_save(flags); 392 __mod_zone_page_state(zone, item, delta); 393 local_irq_restore(flags); 394} 395EXPORT_SYMBOL(mod_zone_page_state); 396 397void inc_zone_state(struct zone *zone, enum zone_stat_item item) 398{ 399 unsigned long flags; 400 401 local_irq_save(flags); 402 __inc_zone_state(zone, item); 403 local_irq_restore(flags); 404} 405 406void inc_zone_page_state(struct page *page, enum zone_stat_item item) 407{ 408 unsigned long flags; 409 struct zone *zone; 410 411 zone = page_zone(page); 412 local_irq_save(flags); 413 __inc_zone_state(zone, item); 414 local_irq_restore(flags); 415} 416EXPORT_SYMBOL(inc_zone_page_state); 417 418void dec_zone_page_state(struct page *page, enum zone_stat_item item) 419{ 420 unsigned long flags; 421 422 local_irq_save(flags); 423 __dec_zone_page_state(page, item); 424 local_irq_restore(flags); 425} 426EXPORT_SYMBOL(dec_zone_page_state); 427#endif 428 429 430/* 431 * Fold a differential into the global counters. 432 * Returns the number of counters updated. 433 */ 434static int fold_diff(int *diff) 435{ 436 int i; 437 int changes = 0; 438 439 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) 440 if (diff[i]) { 441 atomic_long_add(diff[i], &vm_stat[i]); 442 changes++; 443 } 444 return changes; 445} 446 447/* 448 * Update the zone counters for the current cpu. 449 * 450 * Note that refresh_cpu_vm_stats strives to only access 451 * node local memory. The per cpu pagesets on remote zones are placed 452 * in the memory local to the processor using that pageset. So the 453 * loop over all zones will access a series of cachelines local to 454 * the processor. 455 * 456 * The call to zone_page_state_add updates the cachelines with the 457 * statistics in the remote zone struct as well as the global cachelines 458 * with the global counters. These could cause remote node cache line 459 * bouncing and will have to be only done when necessary. 460 * 461 * The function returns the number of global counters updated. 462 */ 463static int refresh_cpu_vm_stats(void) 464{ 465 struct zone *zone; 466 int i; 467 int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, }; 468 int changes = 0; 469 470 for_each_populated_zone(zone) { 471 struct per_cpu_pageset __percpu *p = zone->pageset; 472 473 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) { 474 int v; 475 476 v = this_cpu_xchg(p->vm_stat_diff[i], 0); 477 if (v) { 478 479 atomic_long_add(v, &zone->vm_stat[i]); 480 global_diff[i] += v; 481#ifdef CONFIG_NUMA 482 /* 3 seconds idle till flush */ 483 __this_cpu_write(p->expire, 3); 484#endif 485 } 486 } 487 cond_resched(); 488#ifdef CONFIG_NUMA 489 /* 490 * Deal with draining the remote pageset of this 491 * processor 492 * 493 * Check if there are pages remaining in this pageset 494 * if not then there is nothing to expire. 495 */ 496 if (!__this_cpu_read(p->expire) || 497 !__this_cpu_read(p->pcp.count)) 498 continue; 499 500 /* 501 * We never drain zones local to this processor. 502 */ 503 if (zone_to_nid(zone) == numa_node_id()) { 504 __this_cpu_write(p->expire, 0); 505 continue; 506 } 507 508 if (__this_cpu_dec_return(p->expire)) 509 continue; 510 511 if (__this_cpu_read(p->pcp.count)) { 512 drain_zone_pages(zone, this_cpu_ptr(&p->pcp)); 513 changes++; 514 } 515#endif 516 } 517 changes += fold_diff(global_diff); 518 return changes; 519} 520 521/* 522 * Fold the data for an offline cpu into the global array. 523 * There cannot be any access by the offline cpu and therefore 524 * synchronization is simplified. 525 */ 526void cpu_vm_stats_fold(int cpu) 527{ 528 struct zone *zone; 529 int i; 530 int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, }; 531 532 for_each_populated_zone(zone) { 533 struct per_cpu_pageset *p; 534 535 p = per_cpu_ptr(zone->pageset, cpu); 536 537 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) 538 if (p->vm_stat_diff[i]) { 539 int v; 540 541 v = p->vm_stat_diff[i]; 542 p->vm_stat_diff[i] = 0; 543 atomic_long_add(v, &zone->vm_stat[i]); 544 global_diff[i] += v; 545 } 546 } 547 548 fold_diff(global_diff); 549} 550 551/* 552 * this is only called if !populated_zone(zone), which implies no other users of 553 * pset->vm_stat_diff[] exsist. 554 */ 555void drain_zonestat(struct zone *zone, struct per_cpu_pageset *pset) 556{ 557 int i; 558 559 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) 560 if (pset->vm_stat_diff[i]) { 561 int v = pset->vm_stat_diff[i]; 562 pset->vm_stat_diff[i] = 0; 563 atomic_long_add(v, &zone->vm_stat[i]); 564 atomic_long_add(v, &vm_stat[i]); 565 } 566} 567#endif 568 569#ifdef CONFIG_NUMA 570/* 571 * zonelist = the list of zones passed to the allocator 572 * z = the zone from which the allocation occurred. 573 * 574 * Must be called with interrupts disabled. 575 * 576 * When __GFP_OTHER_NODE is set assume the node of the preferred 577 * zone is the local node. This is useful for daemons who allocate 578 * memory on behalf of other processes. 579 */ 580void zone_statistics(struct zone *preferred_zone, struct zone *z, gfp_t flags) 581{ 582 if (z->zone_pgdat == preferred_zone->zone_pgdat) { 583 __inc_zone_state(z, NUMA_HIT); 584 } else { 585 __inc_zone_state(z, NUMA_MISS); 586 __inc_zone_state(preferred_zone, NUMA_FOREIGN); 587 } 588 if (z->node == ((flags & __GFP_OTHER_NODE) ? 589 preferred_zone->node : numa_node_id())) 590 __inc_zone_state(z, NUMA_LOCAL); 591 else 592 __inc_zone_state(z, NUMA_OTHER); 593} 594#endif 595 596#ifdef CONFIG_COMPACTION 597 598struct contig_page_info { 599 unsigned long free_pages; 600 unsigned long free_blocks_total; 601 unsigned long free_blocks_suitable; 602}; 603 604/* 605 * Calculate the number of free pages in a zone, how many contiguous 606 * pages are free and how many are large enough to satisfy an allocation of 607 * the target size. Note that this function makes no attempt to estimate 608 * how many suitable free blocks there *might* be if MOVABLE pages were 609 * migrated. Calculating that is possible, but expensive and can be 610 * figured out from userspace 611 */ 612static void fill_contig_page_info(struct zone *zone, 613 unsigned int suitable_order, 614 struct contig_page_info *info) 615{ 616 unsigned int order; 617 618 info->free_pages = 0; 619 info->free_blocks_total = 0; 620 info->free_blocks_suitable = 0; 621 622 for (order = 0; order < MAX_ORDER; order++) { 623 unsigned long blocks; 624 625 /* Count number of free blocks */ 626 blocks = zone->free_area[order].nr_free; 627 info->free_blocks_total += blocks; 628 629 /* Count free base pages */ 630 info->free_pages += blocks << order; 631 632 /* Count the suitable free blocks */ 633 if (order >= suitable_order) 634 info->free_blocks_suitable += blocks << 635 (order - suitable_order); 636 } 637} 638 639/* 640 * A fragmentation index only makes sense if an allocation of a requested 641 * size would fail. If that is true, the fragmentation index indicates 642 * whether external fragmentation or a lack of memory was the problem. 643 * The value can be used to determine if page reclaim or compaction 644 * should be used 645 */ 646static int __fragmentation_index(unsigned int order, struct contig_page_info *info) 647{ 648 unsigned long requested = 1UL << order; 649 650 if (!info->free_blocks_total) 651 return 0; 652 653 /* Fragmentation index only makes sense when a request would fail */ 654 if (info->free_blocks_suitable) 655 return -1000; 656 657 /* 658 * Index is between 0 and 1 so return within 3 decimal places 659 * 660 * 0 => allocation would fail due to lack of memory 661 * 1 => allocation would fail due to fragmentation 662 */ 663 return 1000 - div_u64( (1000+(div_u64(info->free_pages * 1000ULL, requested))), info->free_blocks_total); 664} 665 666/* Same as __fragmentation index but allocs contig_page_info on stack */ 667int fragmentation_index(struct zone *zone, unsigned int order) 668{ 669 struct contig_page_info info; 670 671 fill_contig_page_info(zone, order, &info); 672 return __fragmentation_index(order, &info); 673} 674#endif 675 676#if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS) || defined(CONFIG_NUMA) 677#ifdef CONFIG_ZONE_DMA 678#define TEXT_FOR_DMA(xx) xx "_dma", 679#else 680#define TEXT_FOR_DMA(xx) 681#endif 682 683#ifdef CONFIG_ZONE_DMA32 684#define TEXT_FOR_DMA32(xx) xx "_dma32", 685#else 686#define TEXT_FOR_DMA32(xx) 687#endif 688 689#ifdef CONFIG_HIGHMEM 690#define TEXT_FOR_HIGHMEM(xx) xx "_high", 691#else 692#define TEXT_FOR_HIGHMEM(xx) 693#endif 694 695#define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \ 696 TEXT_FOR_HIGHMEM(xx) xx "_movable", 697 698const char * const vmstat_text[] = { 699 /* enum zone_stat_item countes */ 700 "nr_free_pages", 701 "nr_alloc_batch", 702 "nr_inactive_anon", 703 "nr_active_anon", 704 "nr_inactive_file", 705 "nr_active_file", 706 "nr_unevictable", 707 "nr_mlock", 708 "nr_anon_pages", 709 "nr_mapped", 710 "nr_file_pages", 711 "nr_dirty", 712 "nr_writeback", 713 "nr_slab_reclaimable", 714 "nr_slab_unreclaimable", 715 "nr_page_table_pages", 716 "nr_kernel_stack", 717 "nr_unstable", 718 "nr_bounce", 719 "nr_vmscan_write", 720 "nr_vmscan_immediate_reclaim", 721 "nr_writeback_temp", 722 "nr_isolated_anon", 723 "nr_isolated_file", 724 "nr_shmem", 725 "nr_dirtied", 726 "nr_written", 727 "nr_pages_scanned", 728 729#ifdef CONFIG_NUMA 730 "numa_hit", 731 "numa_miss", 732 "numa_foreign", 733 "numa_interleave", 734 "numa_local", 735 "numa_other", 736#endif 737 "workingset_refault", 738 "workingset_activate", 739 "workingset_nodereclaim", 740 "nr_anon_transparent_hugepages", 741 "nr_free_cma", 742 743 /* enum writeback_stat_item counters */ 744 "nr_dirty_threshold", 745 "nr_dirty_background_threshold", 746 747#ifdef CONFIG_VM_EVENT_COUNTERS 748 /* enum vm_event_item counters */ 749 "pgpgin", 750 "pgpgout", 751 "pswpin", 752 "pswpout", 753 754 TEXTS_FOR_ZONES("pgalloc") 755 756 "pgfree", 757 "pgactivate", 758 "pgdeactivate", 759 760 "pgfault", 761 "pgmajfault", 762 763 TEXTS_FOR_ZONES("pgrefill") 764 TEXTS_FOR_ZONES("pgsteal_kswapd") 765 TEXTS_FOR_ZONES("pgsteal_direct") 766 TEXTS_FOR_ZONES("pgscan_kswapd") 767 TEXTS_FOR_ZONES("pgscan_direct") 768 "pgscan_direct_throttle", 769 770#ifdef CONFIG_NUMA 771 "zone_reclaim_failed", 772#endif 773 "pginodesteal", 774 "slabs_scanned", 775 "kswapd_inodesteal", 776 "kswapd_low_wmark_hit_quickly", 777 "kswapd_high_wmark_hit_quickly", 778 "pageoutrun", 779 "allocstall", 780 781 "pgrotated", 782 783 "drop_pagecache", 784 "drop_slab", 785 786#ifdef CONFIG_NUMA_BALANCING 787 "numa_pte_updates", 788 "numa_huge_pte_updates", 789 "numa_hint_faults", 790 "numa_hint_faults_local", 791 "numa_pages_migrated", 792#endif 793#ifdef CONFIG_MIGRATION 794 "pgmigrate_success", 795 "pgmigrate_fail", 796#endif 797#ifdef CONFIG_COMPACTION 798 "compact_migrate_scanned", 799 "compact_free_scanned", 800 "compact_isolated", 801 "compact_stall", 802 "compact_fail", 803 "compact_success", 804#endif 805 806#ifdef CONFIG_HUGETLB_PAGE 807 "htlb_buddy_alloc_success", 808 "htlb_buddy_alloc_fail", 809#endif 810 "unevictable_pgs_culled", 811 "unevictable_pgs_scanned", 812 "unevictable_pgs_rescued", 813 "unevictable_pgs_mlocked", 814 "unevictable_pgs_munlocked", 815 "unevictable_pgs_cleared", 816 "unevictable_pgs_stranded", 817 818#ifdef CONFIG_TRANSPARENT_HUGEPAGE 819 "thp_fault_alloc", 820 "thp_fault_fallback", 821 "thp_collapse_alloc", 822 "thp_collapse_alloc_failed", 823 "thp_split", 824 "thp_zero_page_alloc", 825 "thp_zero_page_alloc_failed", 826#endif 827#ifdef CONFIG_MEMORY_BALLOON 828 "balloon_inflate", 829 "balloon_deflate", 830#ifdef CONFIG_BALLOON_COMPACTION 831 "balloon_migrate", 832#endif 833#endif /* CONFIG_MEMORY_BALLOON */ 834#ifdef CONFIG_DEBUG_TLBFLUSH 835#ifdef CONFIG_SMP 836 "nr_tlb_remote_flush", 837 "nr_tlb_remote_flush_received", 838#endif /* CONFIG_SMP */ 839 "nr_tlb_local_flush_all", 840 "nr_tlb_local_flush_one", 841#endif /* CONFIG_DEBUG_TLBFLUSH */ 842 843#ifdef CONFIG_DEBUG_VM_VMACACHE 844 "vmacache_find_calls", 845 "vmacache_find_hits", 846 "vmacache_full_flushes", 847#endif 848#endif /* CONFIG_VM_EVENTS_COUNTERS */ 849}; 850#endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA */ 851 852 853#if (defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)) || \ 854 defined(CONFIG_PROC_FS) 855static void *frag_start(struct seq_file *m, loff_t *pos) 856{ 857 pg_data_t *pgdat; 858 loff_t node = *pos; 859 860 for (pgdat = first_online_pgdat(); 861 pgdat && node; 862 pgdat = next_online_pgdat(pgdat)) 863 --node; 864 865 return pgdat; 866} 867 868static void *frag_next(struct seq_file *m, void *arg, loff_t *pos) 869{ 870 pg_data_t *pgdat = (pg_data_t *)arg; 871 872 (*pos)++; 873 return next_online_pgdat(pgdat); 874} 875 876static void frag_stop(struct seq_file *m, void *arg) 877{ 878} 879 880/* Walk all the zones in a node and print using a callback */ 881static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat, 882 void (*print)(struct seq_file *m, pg_data_t *, struct zone *)) 883{ 884 struct zone *zone; 885 struct zone *node_zones = pgdat->node_zones; 886 unsigned long flags; 887 888 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) { 889 if (!populated_zone(zone)) 890 continue; 891 892 spin_lock_irqsave(&zone->lock, flags); 893 print(m, pgdat, zone); 894 spin_unlock_irqrestore(&zone->lock, flags); 895 } 896} 897#endif 898 899#ifdef CONFIG_PROC_FS 900static char * const migratetype_names[MIGRATE_TYPES] = { 901 "Unmovable", 902 "Reclaimable", 903 "Movable", 904 "Reserve", 905#ifdef CONFIG_CMA 906 "CMA", 907#endif 908#ifdef CONFIG_MEMORY_ISOLATION 909 "Isolate", 910#endif 911}; 912 913static void frag_show_print(struct seq_file *m, pg_data_t *pgdat, 914 struct zone *zone) 915{ 916 int order; 917 918 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name); 919 for (order = 0; order < MAX_ORDER; ++order) 920 seq_printf(m, "%6lu ", zone->free_area[order].nr_free); 921 seq_putc(m, '\n'); 922} 923 924/* 925 * This walks the free areas for each zone. 926 */ 927static int frag_show(struct seq_file *m, void *arg) 928{ 929 pg_data_t *pgdat = (pg_data_t *)arg; 930 walk_zones_in_node(m, pgdat, frag_show_print); 931 return 0; 932} 933 934static void pagetypeinfo_showfree_print(struct seq_file *m, 935 pg_data_t *pgdat, struct zone *zone) 936{ 937 int order, mtype; 938 939 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) { 940 seq_printf(m, "Node %4d, zone %8s, type %12s ", 941 pgdat->node_id, 942 zone->name, 943 migratetype_names[mtype]); 944 for (order = 0; order < MAX_ORDER; ++order) { 945 unsigned long freecount = 0; 946 struct free_area *area; 947 struct list_head *curr; 948 949 area = &(zone->free_area[order]); 950 951 list_for_each(curr, &area->free_list[mtype]) 952 freecount++; 953 seq_printf(m, "%6lu ", freecount); 954 } 955 seq_putc(m, '\n'); 956 } 957} 958 959/* Print out the free pages at each order for each migatetype */ 960static int pagetypeinfo_showfree(struct seq_file *m, void *arg) 961{ 962 int order; 963 pg_data_t *pgdat = (pg_data_t *)arg; 964 965 /* Print header */ 966 seq_printf(m, "%-43s ", "Free pages count per migrate type at order"); 967 for (order = 0; order < MAX_ORDER; ++order) 968 seq_printf(m, "%6d ", order); 969 seq_putc(m, '\n'); 970 971 walk_zones_in_node(m, pgdat, pagetypeinfo_showfree_print); 972 973 return 0; 974} 975 976static void pagetypeinfo_showblockcount_print(struct seq_file *m, 977 pg_data_t *pgdat, struct zone *zone) 978{ 979 int mtype; 980 unsigned long pfn; 981 unsigned long start_pfn = zone->zone_start_pfn; 982 unsigned long end_pfn = zone_end_pfn(zone); 983 unsigned long count[MIGRATE_TYPES] = { 0, }; 984 985 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) { 986 struct page *page; 987 988 if (!pfn_valid(pfn)) 989 continue; 990 991 page = pfn_to_page(pfn); 992 993 /* Watch for unexpected holes punched in the memmap */ 994 if (!memmap_valid_within(pfn, page, zone)) 995 continue; 996 997 mtype = get_pageblock_migratetype(page); 998 999 if (mtype < MIGRATE_TYPES) 1000 count[mtype]++; 1001 } 1002 1003 /* Print counts */ 1004 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name); 1005 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) 1006 seq_printf(m, "%12lu ", count[mtype]); 1007 seq_putc(m, '\n'); 1008} 1009 1010/* Print out the free pages at each order for each migratetype */ 1011static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg) 1012{ 1013 int mtype; 1014 pg_data_t *pgdat = (pg_data_t *)arg; 1015 1016 seq_printf(m, "\n%-23s", "Number of blocks type "); 1017 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) 1018 seq_printf(m, "%12s ", migratetype_names[mtype]); 1019 seq_putc(m, '\n'); 1020 walk_zones_in_node(m, pgdat, pagetypeinfo_showblockcount_print); 1021 1022 return 0; 1023} 1024 1025#ifdef CONFIG_PAGE_OWNER 1026static void pagetypeinfo_showmixedcount_print(struct seq_file *m, 1027 pg_data_t *pgdat, 1028 struct zone *zone) 1029{ 1030 struct page *page; 1031 struct page_ext *page_ext; 1032 unsigned long pfn = zone->zone_start_pfn, block_end_pfn; 1033 unsigned long end_pfn = pfn + zone->spanned_pages; 1034 unsigned long count[MIGRATE_TYPES] = { 0, }; 1035 int pageblock_mt, page_mt; 1036 int i; 1037 1038 /* Scan block by block. First and last block may be incomplete */ 1039 pfn = zone->zone_start_pfn; 1040 1041 /* 1042 * Walk the zone in pageblock_nr_pages steps. If a page block spans 1043 * a zone boundary, it will be double counted between zones. This does 1044 * not matter as the mixed block count will still be correct 1045 */ 1046 for (; pfn < end_pfn; ) { 1047 if (!pfn_valid(pfn)) { 1048 pfn = ALIGN(pfn + 1, MAX_ORDER_NR_PAGES); 1049 continue; 1050 } 1051 1052 block_end_pfn = ALIGN(pfn + 1, pageblock_nr_pages); 1053 block_end_pfn = min(block_end_pfn, end_pfn); 1054 1055 page = pfn_to_page(pfn); 1056 pageblock_mt = get_pfnblock_migratetype(page, pfn); 1057 1058 for (; pfn < block_end_pfn; pfn++) { 1059 if (!pfn_valid_within(pfn)) 1060 continue; 1061 1062 page = pfn_to_page(pfn); 1063 if (PageBuddy(page)) { 1064 pfn += (1UL << page_order(page)) - 1; 1065 continue; 1066 } 1067 1068 if (PageReserved(page)) 1069 continue; 1070 1071 page_ext = lookup_page_ext(page); 1072 1073 if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags)) 1074 continue; 1075 1076 page_mt = gfpflags_to_migratetype(page_ext->gfp_mask); 1077 if (pageblock_mt != page_mt) { 1078 if (is_migrate_cma(pageblock_mt)) 1079 count[MIGRATE_MOVABLE]++; 1080 else 1081 count[pageblock_mt]++; 1082 1083 pfn = block_end_pfn; 1084 break; 1085 } 1086 pfn += (1UL << page_ext->order) - 1; 1087 } 1088 } 1089 1090 /* Print counts */ 1091 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name); 1092 for (i = 0; i < MIGRATE_TYPES; i++) 1093 seq_printf(m, "%12lu ", count[i]); 1094 seq_putc(m, '\n'); 1095} 1096#endif /* CONFIG_PAGE_OWNER */ 1097 1098/* 1099 * Print out the number of pageblocks for each migratetype that contain pages 1100 * of other types. This gives an indication of how well fallbacks are being 1101 * contained by rmqueue_fallback(). It requires information from PAGE_OWNER 1102 * to determine what is going on 1103 */ 1104static void pagetypeinfo_showmixedcount(struct seq_file *m, pg_data_t *pgdat) 1105{ 1106#ifdef CONFIG_PAGE_OWNER 1107 int mtype; 1108 1109 if (!page_owner_inited) 1110 return; 1111 1112 drain_all_pages(NULL); 1113 1114 seq_printf(m, "\n%-23s", "Number of mixed blocks "); 1115 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) 1116 seq_printf(m, "%12s ", migratetype_names[mtype]); 1117 seq_putc(m, '\n'); 1118 1119 walk_zones_in_node(m, pgdat, pagetypeinfo_showmixedcount_print); 1120#endif /* CONFIG_PAGE_OWNER */ 1121} 1122 1123/* 1124 * This prints out statistics in relation to grouping pages by mobility. 1125 * It is expensive to collect so do not constantly read the file. 1126 */ 1127static int pagetypeinfo_show(struct seq_file *m, void *arg) 1128{ 1129 pg_data_t *pgdat = (pg_data_t *)arg; 1130 1131 /* check memoryless node */ 1132 if (!node_state(pgdat->node_id, N_MEMORY)) 1133 return 0; 1134 1135 seq_printf(m, "Page block order: %d\n", pageblock_order); 1136 seq_printf(m, "Pages per block: %lu\n", pageblock_nr_pages); 1137 seq_putc(m, '\n'); 1138 pagetypeinfo_showfree(m, pgdat); 1139 pagetypeinfo_showblockcount(m, pgdat); 1140 pagetypeinfo_showmixedcount(m, pgdat); 1141 1142 return 0; 1143} 1144 1145static const struct seq_operations fragmentation_op = { 1146 .start = frag_start, 1147 .next = frag_next, 1148 .stop = frag_stop, 1149 .show = frag_show, 1150}; 1151 1152static int fragmentation_open(struct inode *inode, struct file *file) 1153{ 1154 return seq_open(file, &fragmentation_op); 1155} 1156 1157static const struct file_operations fragmentation_file_operations = { 1158 .open = fragmentation_open, 1159 .read = seq_read, 1160 .llseek = seq_lseek, 1161 .release = seq_release, 1162}; 1163 1164static const struct seq_operations pagetypeinfo_op = { 1165 .start = frag_start, 1166 .next = frag_next, 1167 .stop = frag_stop, 1168 .show = pagetypeinfo_show, 1169}; 1170 1171static int pagetypeinfo_open(struct inode *inode, struct file *file) 1172{ 1173 return seq_open(file, &pagetypeinfo_op); 1174} 1175 1176static const struct file_operations pagetypeinfo_file_ops = { 1177 .open = pagetypeinfo_open, 1178 .read = seq_read, 1179 .llseek = seq_lseek, 1180 .release = seq_release, 1181}; 1182 1183static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat, 1184 struct zone *zone) 1185{ 1186 int i; 1187 seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name); 1188 seq_printf(m, 1189 "\n pages free %lu" 1190 "\n min %lu" 1191 "\n low %lu" 1192 "\n high %lu" 1193 "\n scanned %lu" 1194 "\n spanned %lu" 1195 "\n present %lu" 1196 "\n managed %lu", 1197 zone_page_state(zone, NR_FREE_PAGES), 1198 min_wmark_pages(zone), 1199 low_wmark_pages(zone), 1200 high_wmark_pages(zone), 1201 zone_page_state(zone, NR_PAGES_SCANNED), 1202 zone->spanned_pages, 1203 zone->present_pages, 1204 zone->managed_pages); 1205 1206 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) 1207 seq_printf(m, "\n %-12s %lu", vmstat_text[i], 1208 zone_page_state(zone, i)); 1209 1210 seq_printf(m, 1211 "\n protection: (%ld", 1212 zone->lowmem_reserve[0]); 1213 for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++) 1214 seq_printf(m, ", %ld", zone->lowmem_reserve[i]); 1215 seq_printf(m, 1216 ")" 1217 "\n pagesets"); 1218 for_each_online_cpu(i) { 1219 struct per_cpu_pageset *pageset; 1220 1221 pageset = per_cpu_ptr(zone->pageset, i); 1222 seq_printf(m, 1223 "\n cpu: %i" 1224 "\n count: %i" 1225 "\n high: %i" 1226 "\n batch: %i", 1227 i, 1228 pageset->pcp.count, 1229 pageset->pcp.high, 1230 pageset->pcp.batch); 1231#ifdef CONFIG_SMP 1232 seq_printf(m, "\n vm stats threshold: %d", 1233 pageset->stat_threshold); 1234#endif 1235 } 1236 seq_printf(m, 1237 "\n all_unreclaimable: %u" 1238 "\n start_pfn: %lu" 1239 "\n inactive_ratio: %u", 1240 !zone_reclaimable(zone), 1241 zone->zone_start_pfn, 1242 zone->inactive_ratio); 1243 seq_putc(m, '\n'); 1244} 1245 1246/* 1247 * Output information about zones in @pgdat. 1248 */ 1249static int zoneinfo_show(struct seq_file *m, void *arg) 1250{ 1251 pg_data_t *pgdat = (pg_data_t *)arg; 1252 walk_zones_in_node(m, pgdat, zoneinfo_show_print); 1253 return 0; 1254} 1255 1256static const struct seq_operations zoneinfo_op = { 1257 .start = frag_start, /* iterate over all zones. The same as in 1258 * fragmentation. */ 1259 .next = frag_next, 1260 .stop = frag_stop, 1261 .show = zoneinfo_show, 1262}; 1263 1264static int zoneinfo_open(struct inode *inode, struct file *file) 1265{ 1266 return seq_open(file, &zoneinfo_op); 1267} 1268 1269static const struct file_operations proc_zoneinfo_file_operations = { 1270 .open = zoneinfo_open, 1271 .read = seq_read, 1272 .llseek = seq_lseek, 1273 .release = seq_release, 1274}; 1275 1276enum writeback_stat_item { 1277 NR_DIRTY_THRESHOLD, 1278 NR_DIRTY_BG_THRESHOLD, 1279 NR_VM_WRITEBACK_STAT_ITEMS, 1280}; 1281 1282static void *vmstat_start(struct seq_file *m, loff_t *pos) 1283{ 1284 unsigned long *v; 1285 int i, stat_items_size; 1286 1287 if (*pos >= ARRAY_SIZE(vmstat_text)) 1288 return NULL; 1289 stat_items_size = NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long) + 1290 NR_VM_WRITEBACK_STAT_ITEMS * sizeof(unsigned long); 1291 1292#ifdef CONFIG_VM_EVENT_COUNTERS 1293 stat_items_size += sizeof(struct vm_event_state); 1294#endif 1295 1296 v = kmalloc(stat_items_size, GFP_KERNEL); 1297 m->private = v; 1298 if (!v) 1299 return ERR_PTR(-ENOMEM); 1300 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) 1301 v[i] = global_page_state(i); 1302 v += NR_VM_ZONE_STAT_ITEMS; 1303 1304 global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD, 1305 v + NR_DIRTY_THRESHOLD); 1306 v += NR_VM_WRITEBACK_STAT_ITEMS; 1307 1308#ifdef CONFIG_VM_EVENT_COUNTERS 1309 all_vm_events(v); 1310 v[PGPGIN] /= 2; /* sectors -> kbytes */ 1311 v[PGPGOUT] /= 2; 1312#endif 1313 return (unsigned long *)m->private + *pos; 1314} 1315 1316static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos) 1317{ 1318 (*pos)++; 1319 if (*pos >= ARRAY_SIZE(vmstat_text)) 1320 return NULL; 1321 return (unsigned long *)m->private + *pos; 1322} 1323 1324static int vmstat_show(struct seq_file *m, void *arg) 1325{ 1326 unsigned long *l = arg; 1327 unsigned long off = l - (unsigned long *)m->private; 1328 1329 seq_printf(m, "%s %lu\n", vmstat_text[off], *l); 1330 return 0; 1331} 1332 1333static void vmstat_stop(struct seq_file *m, void *arg) 1334{ 1335 kfree(m->private); 1336 m->private = NULL; 1337} 1338 1339static const struct seq_operations vmstat_op = { 1340 .start = vmstat_start, 1341 .next = vmstat_next, 1342 .stop = vmstat_stop, 1343 .show = vmstat_show, 1344}; 1345 1346static int vmstat_open(struct inode *inode, struct file *file) 1347{ 1348 return seq_open(file, &vmstat_op); 1349} 1350 1351static const struct file_operations proc_vmstat_file_operations = { 1352 .open = vmstat_open, 1353 .read = seq_read, 1354 .llseek = seq_lseek, 1355 .release = seq_release, 1356}; 1357#endif /* CONFIG_PROC_FS */ 1358 1359#ifdef CONFIG_SMP 1360static DEFINE_PER_CPU(struct delayed_work, vmstat_work); 1361int sysctl_stat_interval __read_mostly = HZ; 1362static cpumask_var_t cpu_stat_off; 1363 1364static void vmstat_update(struct work_struct *w) 1365{ 1366 if (refresh_cpu_vm_stats()) 1367 /* 1368 * Counters were updated so we expect more updates 1369 * to occur in the future. Keep on running the 1370 * update worker thread. 1371 */ 1372 schedule_delayed_work(this_cpu_ptr(&vmstat_work), 1373 round_jiffies_relative(sysctl_stat_interval)); 1374 else { 1375 /* 1376 * We did not update any counters so the app may be in 1377 * a mode where it does not cause counter updates. 1378 * We may be uselessly running vmstat_update. 1379 * Defer the checking for differentials to the 1380 * shepherd thread on a different processor. 1381 */ 1382 int r; 1383 /* 1384 * Shepherd work thread does not race since it never 1385 * changes the bit if its zero but the cpu 1386 * online / off line code may race if 1387 * worker threads are still allowed during 1388 * shutdown / startup. 1389 */ 1390 r = cpumask_test_and_set_cpu(smp_processor_id(), 1391 cpu_stat_off); 1392 VM_BUG_ON(r); 1393 } 1394} 1395 1396/* 1397 * Check if the diffs for a certain cpu indicate that 1398 * an update is needed. 1399 */ 1400static bool need_update(int cpu) 1401{ 1402 struct zone *zone; 1403 1404 for_each_populated_zone(zone) { 1405 struct per_cpu_pageset *p = per_cpu_ptr(zone->pageset, cpu); 1406 1407 BUILD_BUG_ON(sizeof(p->vm_stat_diff[0]) != 1); 1408 /* 1409 * The fast way of checking if there are any vmstat diffs. 1410 * This works because the diffs are byte sized items. 1411 */ 1412 if (memchr_inv(p->vm_stat_diff, 0, NR_VM_ZONE_STAT_ITEMS)) 1413 return true; 1414 1415 } 1416 return false; 1417} 1418 1419 1420/* 1421 * Shepherd worker thread that checks the 1422 * differentials of processors that have their worker 1423 * threads for vm statistics updates disabled because of 1424 * inactivity. 1425 */ 1426static void vmstat_shepherd(struct work_struct *w); 1427 1428static DECLARE_DELAYED_WORK(shepherd, vmstat_shepherd); 1429 1430static void vmstat_shepherd(struct work_struct *w) 1431{ 1432 int cpu; 1433 1434 get_online_cpus(); 1435 /* Check processors whose vmstat worker threads have been disabled */ 1436 for_each_cpu(cpu, cpu_stat_off) 1437 if (need_update(cpu) && 1438 cpumask_test_and_clear_cpu(cpu, cpu_stat_off)) 1439 1440 schedule_delayed_work_on(cpu, 1441 &per_cpu(vmstat_work, cpu), 0); 1442 1443 put_online_cpus(); 1444 1445 schedule_delayed_work(&shepherd, 1446 round_jiffies_relative(sysctl_stat_interval)); 1447 1448} 1449 1450static void __init start_shepherd_timer(void) 1451{ 1452 int cpu; 1453 1454 for_each_possible_cpu(cpu) 1455 INIT_DELAYED_WORK(per_cpu_ptr(&vmstat_work, cpu), 1456 vmstat_update); 1457 1458 if (!alloc_cpumask_var(&cpu_stat_off, GFP_KERNEL)) 1459 BUG(); 1460 cpumask_copy(cpu_stat_off, cpu_online_mask); 1461 1462 schedule_delayed_work(&shepherd, 1463 round_jiffies_relative(sysctl_stat_interval)); 1464} 1465 1466static void vmstat_cpu_dead(int node) 1467{ 1468 int cpu; 1469 1470 get_online_cpus(); 1471 for_each_online_cpu(cpu) 1472 if (cpu_to_node(cpu) == node) 1473 goto end; 1474 1475 node_clear_state(node, N_CPU); 1476end: 1477 put_online_cpus(); 1478} 1479 1480/* 1481 * Use the cpu notifier to insure that the thresholds are recalculated 1482 * when necessary. 1483 */ 1484static int vmstat_cpuup_callback(struct notifier_block *nfb, 1485 unsigned long action, 1486 void *hcpu) 1487{ 1488 long cpu = (long)hcpu; 1489 1490 switch (action) { 1491 case CPU_ONLINE: 1492 case CPU_ONLINE_FROZEN: 1493 refresh_zone_stat_thresholds(); 1494 node_set_state(cpu_to_node(cpu), N_CPU); 1495 cpumask_set_cpu(cpu, cpu_stat_off); 1496 break; 1497 case CPU_DOWN_PREPARE: 1498 case CPU_DOWN_PREPARE_FROZEN: 1499 cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu)); 1500 cpumask_clear_cpu(cpu, cpu_stat_off); 1501 break; 1502 case CPU_DOWN_FAILED: 1503 case CPU_DOWN_FAILED_FROZEN: 1504 cpumask_set_cpu(cpu, cpu_stat_off); 1505 break; 1506 case CPU_DEAD: 1507 case CPU_DEAD_FROZEN: 1508 refresh_zone_stat_thresholds(); 1509 vmstat_cpu_dead(cpu_to_node(cpu)); 1510 break; 1511 default: 1512 break; 1513 } 1514 return NOTIFY_OK; 1515} 1516 1517static struct notifier_block vmstat_notifier = 1518 { &vmstat_cpuup_callback, NULL, 0 }; 1519#endif 1520 1521static int __init setup_vmstat(void) 1522{ 1523#ifdef CONFIG_SMP 1524 cpu_notifier_register_begin(); 1525 __register_cpu_notifier(&vmstat_notifier); 1526 1527 start_shepherd_timer(); 1528 cpu_notifier_register_done(); 1529#endif 1530#ifdef CONFIG_PROC_FS 1531 proc_create("buddyinfo", S_IRUGO, NULL, &fragmentation_file_operations); 1532 proc_create("pagetypeinfo", S_IRUGO, NULL, &pagetypeinfo_file_ops); 1533 proc_create("vmstat", S_IRUGO, NULL, &proc_vmstat_file_operations); 1534 proc_create("zoneinfo", S_IRUGO, NULL, &proc_zoneinfo_file_operations); 1535#endif 1536 return 0; 1537} 1538module_init(setup_vmstat) 1539 1540#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION) 1541 1542/* 1543 * Return an index indicating how much of the available free memory is 1544 * unusable for an allocation of the requested size. 1545 */ 1546static int unusable_free_index(unsigned int order, 1547 struct contig_page_info *info) 1548{ 1549 /* No free memory is interpreted as all free memory is unusable */ 1550 if (info->free_pages == 0) 1551 return 1000; 1552 1553 /* 1554 * Index should be a value between 0 and 1. Return a value to 3 1555 * decimal places. 1556 * 1557 * 0 => no fragmentation 1558 * 1 => high fragmentation 1559 */ 1560 return div_u64((info->free_pages - (info->free_blocks_suitable << order)) * 1000ULL, info->free_pages); 1561 1562} 1563 1564static void unusable_show_print(struct seq_file *m, 1565 pg_data_t *pgdat, struct zone *zone) 1566{ 1567 unsigned int order; 1568 int index; 1569 struct contig_page_info info; 1570 1571 seq_printf(m, "Node %d, zone %8s ", 1572 pgdat->node_id, 1573 zone->name); 1574 for (order = 0; order < MAX_ORDER; ++order) { 1575 fill_contig_page_info(zone, order, &info); 1576 index = unusable_free_index(order, &info); 1577 seq_printf(m, "%d.%03d ", index / 1000, index % 1000); 1578 } 1579 1580 seq_putc(m, '\n'); 1581} 1582 1583/* 1584 * Display unusable free space index 1585 * 1586 * The unusable free space index measures how much of the available free 1587 * memory cannot be used to satisfy an allocation of a given size and is a 1588 * value between 0 and 1. The higher the value, the more of free memory is 1589 * unusable and by implication, the worse the external fragmentation is. This 1590 * can be expressed as a percentage by multiplying by 100. 1591 */ 1592static int unusable_show(struct seq_file *m, void *arg) 1593{ 1594 pg_data_t *pgdat = (pg_data_t *)arg; 1595 1596 /* check memoryless node */ 1597 if (!node_state(pgdat->node_id, N_MEMORY)) 1598 return 0; 1599 1600 walk_zones_in_node(m, pgdat, unusable_show_print); 1601 1602 return 0; 1603} 1604 1605static const struct seq_operations unusable_op = { 1606 .start = frag_start, 1607 .next = frag_next, 1608 .stop = frag_stop, 1609 .show = unusable_show, 1610}; 1611 1612static int unusable_open(struct inode *inode, struct file *file) 1613{ 1614 return seq_open(file, &unusable_op); 1615} 1616 1617static const struct file_operations unusable_file_ops = { 1618 .open = unusable_open, 1619 .read = seq_read, 1620 .llseek = seq_lseek, 1621 .release = seq_release, 1622}; 1623 1624static void extfrag_show_print(struct seq_file *m, 1625 pg_data_t *pgdat, struct zone *zone) 1626{ 1627 unsigned int order; 1628 int index; 1629 1630 /* Alloc on stack as interrupts are disabled for zone walk */ 1631 struct contig_page_info info; 1632 1633 seq_printf(m, "Node %d, zone %8s ", 1634 pgdat->node_id, 1635 zone->name); 1636 for (order = 0; order < MAX_ORDER; ++order) { 1637 fill_contig_page_info(zone, order, &info); 1638 index = __fragmentation_index(order, &info); 1639 seq_printf(m, "%d.%03d ", index / 1000, index % 1000); 1640 } 1641 1642 seq_putc(m, '\n'); 1643} 1644 1645/* 1646 * Display fragmentation index for orders that allocations would fail for 1647 */ 1648static int extfrag_show(struct seq_file *m, void *arg) 1649{ 1650 pg_data_t *pgdat = (pg_data_t *)arg; 1651 1652 walk_zones_in_node(m, pgdat, extfrag_show_print); 1653 1654 return 0; 1655} 1656 1657static const struct seq_operations extfrag_op = { 1658 .start = frag_start, 1659 .next = frag_next, 1660 .stop = frag_stop, 1661 .show = extfrag_show, 1662}; 1663 1664static int extfrag_open(struct inode *inode, struct file *file) 1665{ 1666 return seq_open(file, &extfrag_op); 1667} 1668 1669static const struct file_operations extfrag_file_ops = { 1670 .open = extfrag_open, 1671 .read = seq_read, 1672 .llseek = seq_lseek, 1673 .release = seq_release, 1674}; 1675 1676static int __init extfrag_debug_init(void) 1677{ 1678 struct dentry *extfrag_debug_root; 1679 1680 extfrag_debug_root = debugfs_create_dir("extfrag", NULL); 1681 if (!extfrag_debug_root) 1682 return -ENOMEM; 1683 1684 if (!debugfs_create_file("unusable_index", 0444, 1685 extfrag_debug_root, NULL, &unusable_file_ops)) 1686 goto fail; 1687 1688 if (!debugfs_create_file("extfrag_index", 0444, 1689 extfrag_debug_root, NULL, &extfrag_file_ops)) 1690 goto fail; 1691 1692 return 0; 1693fail: 1694 debugfs_remove_recursive(extfrag_debug_root); 1695 return -ENOMEM; 1696} 1697 1698module_init(extfrag_debug_init); 1699#endif 1700