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