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authorWu Fengguang <fengguang.wu@intel.com>2009-06-16 18:32:27 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2009-06-16 22:47:38 -0400
commit35efa5e993a7a00a50b87d2b7725c3eafc80b083 (patch)
treed46d3840f274c2c933498ab0225e8341d7695e72 /Documentation/vm
parent17e895012f7fe9dc63144990da98c41bbc22d68f (diff)
pagemap: add page-types tool
Add page-types, a handy tool for querying page flags. It will expand some of the overloaded flags: PG_slob_free = PG_private PG_slub_frozen = PG_active PG_slub_debug = PG_error PG_readahead = PG_reclaim and mask out obscure flags except in -raw mode: PG_reserved PG_mlocked PG_mappedtodisk PG_private PG_private_2 PG_owner_priv_1 PG_arch_1 PG_uncached PG_compound* for non hugeTLB pages [akpm@linux-foundation.org: fix warning] Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Matt Mackall <mpm@selenic.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/vm')
-rw-r--r--Documentation/vm/Makefile2
-rw-r--r--Documentation/vm/page-types.c698
2 files changed, 699 insertions, 1 deletions
diff --git a/Documentation/vm/Makefile b/Documentation/vm/Makefile
index 6f562f778b28..27479d43a9b0 100644
--- a/Documentation/vm/Makefile
+++ b/Documentation/vm/Makefile
@@ -2,7 +2,7 @@
2obj- := dummy.o 2obj- := dummy.o
3 3
4# List of programs to build 4# List of programs to build
5hostprogs-y := slabinfo 5hostprogs-y := slabinfo slqbinfo page-types
6 6
7# Tell kbuild to always build the programs 7# Tell kbuild to always build the programs
8always := $(hostprogs-y) 8always := $(hostprogs-y)
diff --git a/Documentation/vm/page-types.c b/Documentation/vm/page-types.c
new file mode 100644
index 000000000000..0833f44ba16b
--- /dev/null
+++ b/Documentation/vm/page-types.c
@@ -0,0 +1,698 @@
1/*
2 * page-types: Tool for querying page flags
3 *
4 * Copyright (C) 2009 Intel corporation
5 * Copyright (C) 2009 Wu Fengguang <fengguang.wu@intel.com>
6 */
7
8#include <stdio.h>
9#include <stdlib.h>
10#include <unistd.h>
11#include <stdint.h>
12#include <stdarg.h>
13#include <string.h>
14#include <getopt.h>
15#include <limits.h>
16#include <sys/types.h>
17#include <sys/errno.h>
18#include <sys/fcntl.h>
19
20
21/*
22 * kernel page flags
23 */
24
25#define KPF_BYTES 8
26#define PROC_KPAGEFLAGS "/proc/kpageflags"
27
28/* copied from kpageflags_read() */
29#define KPF_LOCKED 0
30#define KPF_ERROR 1
31#define KPF_REFERENCED 2
32#define KPF_UPTODATE 3
33#define KPF_DIRTY 4
34#define KPF_LRU 5
35#define KPF_ACTIVE 6
36#define KPF_SLAB 7
37#define KPF_WRITEBACK 8
38#define KPF_RECLAIM 9
39#define KPF_BUDDY 10
40
41/* [11-20] new additions in 2.6.31 */
42#define KPF_MMAP 11
43#define KPF_ANON 12
44#define KPF_SWAPCACHE 13
45#define KPF_SWAPBACKED 14
46#define KPF_COMPOUND_HEAD 15
47#define KPF_COMPOUND_TAIL 16
48#define KPF_HUGE 17
49#define KPF_UNEVICTABLE 18
50#define KPF_NOPAGE 20
51
52/* [32-] kernel hacking assistances */
53#define KPF_RESERVED 32
54#define KPF_MLOCKED 33
55#define KPF_MAPPEDTODISK 34
56#define KPF_PRIVATE 35
57#define KPF_PRIVATE_2 36
58#define KPF_OWNER_PRIVATE 37
59#define KPF_ARCH 38
60#define KPF_UNCACHED 39
61
62/* [48-] take some arbitrary free slots for expanding overloaded flags
63 * not part of kernel API
64 */
65#define KPF_READAHEAD 48
66#define KPF_SLOB_FREE 49
67#define KPF_SLUB_FROZEN 50
68#define KPF_SLUB_DEBUG 51
69
70#define KPF_ALL_BITS ((uint64_t)~0ULL)
71#define KPF_HACKERS_BITS (0xffffULL << 32)
72#define KPF_OVERLOADED_BITS (0xffffULL << 48)
73#define BIT(name) (1ULL << KPF_##name)
74#define BITS_COMPOUND (BIT(COMPOUND_HEAD) | BIT(COMPOUND_TAIL))
75
76static char *page_flag_names[] = {
77 [KPF_LOCKED] = "L:locked",
78 [KPF_ERROR] = "E:error",
79 [KPF_REFERENCED] = "R:referenced",
80 [KPF_UPTODATE] = "U:uptodate",
81 [KPF_DIRTY] = "D:dirty",
82 [KPF_LRU] = "l:lru",
83 [KPF_ACTIVE] = "A:active",
84 [KPF_SLAB] = "S:slab",
85 [KPF_WRITEBACK] = "W:writeback",
86 [KPF_RECLAIM] = "I:reclaim",
87 [KPF_BUDDY] = "B:buddy",
88
89 [KPF_MMAP] = "M:mmap",
90 [KPF_ANON] = "a:anonymous",
91 [KPF_SWAPCACHE] = "s:swapcache",
92 [KPF_SWAPBACKED] = "b:swapbacked",
93 [KPF_COMPOUND_HEAD] = "H:compound_head",
94 [KPF_COMPOUND_TAIL] = "T:compound_tail",
95 [KPF_HUGE] = "G:huge",
96 [KPF_UNEVICTABLE] = "u:unevictable",
97 [KPF_NOPAGE] = "n:nopage",
98
99 [KPF_RESERVED] = "r:reserved",
100 [KPF_MLOCKED] = "m:mlocked",
101 [KPF_MAPPEDTODISK] = "d:mappedtodisk",
102 [KPF_PRIVATE] = "P:private",
103 [KPF_PRIVATE_2] = "p:private_2",
104 [KPF_OWNER_PRIVATE] = "O:owner_private",
105 [KPF_ARCH] = "h:arch",
106 [KPF_UNCACHED] = "c:uncached",
107
108 [KPF_READAHEAD] = "I:readahead",
109 [KPF_SLOB_FREE] = "P:slob_free",
110 [KPF_SLUB_FROZEN] = "A:slub_frozen",
111 [KPF_SLUB_DEBUG] = "E:slub_debug",
112};
113
114
115/*
116 * data structures
117 */
118
119static int opt_raw; /* for kernel developers */
120static int opt_list; /* list pages (in ranges) */
121static int opt_no_summary; /* don't show summary */
122static pid_t opt_pid; /* process to walk */
123
124#define MAX_ADDR_RANGES 1024
125static int nr_addr_ranges;
126static unsigned long opt_offset[MAX_ADDR_RANGES];
127static unsigned long opt_size[MAX_ADDR_RANGES];
128
129#define MAX_BIT_FILTERS 64
130static int nr_bit_filters;
131static uint64_t opt_mask[MAX_BIT_FILTERS];
132static uint64_t opt_bits[MAX_BIT_FILTERS];
133
134static int page_size;
135
136#define PAGES_BATCH (64 << 10) /* 64k pages */
137static int kpageflags_fd;
138static uint64_t kpageflags_buf[KPF_BYTES * PAGES_BATCH];
139
140#define HASH_SHIFT 13
141#define HASH_SIZE (1 << HASH_SHIFT)
142#define HASH_MASK (HASH_SIZE - 1)
143#define HASH_KEY(flags) (flags & HASH_MASK)
144
145static unsigned long total_pages;
146static unsigned long nr_pages[HASH_SIZE];
147static uint64_t page_flags[HASH_SIZE];
148
149
150/*
151 * helper functions
152 */
153
154#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
155
156#define min_t(type, x, y) ({ \
157 type __min1 = (x); \
158 type __min2 = (y); \
159 __min1 < __min2 ? __min1 : __min2; })
160
161unsigned long pages2mb(unsigned long pages)
162{
163 return (pages * page_size) >> 20;
164}
165
166void fatal(const char *x, ...)
167{
168 va_list ap;
169
170 va_start(ap, x);
171 vfprintf(stderr, x, ap);
172 va_end(ap);
173 exit(EXIT_FAILURE);
174}
175
176
177/*
178 * page flag names
179 */
180
181char *page_flag_name(uint64_t flags)
182{
183 static char buf[65];
184 int present;
185 int i, j;
186
187 for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
188 present = (flags >> i) & 1;
189 if (!page_flag_names[i]) {
190 if (present)
191 fatal("unkown flag bit %d\n", i);
192 continue;
193 }
194 buf[j++] = present ? page_flag_names[i][0] : '_';
195 }
196
197 return buf;
198}
199
200char *page_flag_longname(uint64_t flags)
201{
202 static char buf[1024];
203 int i, n;
204
205 for (i = 0, n = 0; i < ARRAY_SIZE(page_flag_names); i++) {
206 if (!page_flag_names[i])
207 continue;
208 if ((flags >> i) & 1)
209 n += snprintf(buf + n, sizeof(buf) - n, "%s,",
210 page_flag_names[i] + 2);
211 }
212 if (n)
213 n--;
214 buf[n] = '\0';
215
216 return buf;
217}
218
219
220/*
221 * page list and summary
222 */
223
224void show_page_range(unsigned long offset, uint64_t flags)
225{
226 static uint64_t flags0;
227 static unsigned long index;
228 static unsigned long count;
229
230 if (flags == flags0 && offset == index + count) {
231 count++;
232 return;
233 }
234
235 if (count)
236 printf("%lu\t%lu\t%s\n",
237 index, count, page_flag_name(flags0));
238
239 flags0 = flags;
240 index = offset;
241 count = 1;
242}
243
244void show_page(unsigned long offset, uint64_t flags)
245{
246 printf("%lu\t%s\n", offset, page_flag_name(flags));
247}
248
249void show_summary(void)
250{
251 int i;
252
253 printf(" flags\tpage-count MB"
254 " symbolic-flags\t\t\tlong-symbolic-flags\n");
255
256 for (i = 0; i < ARRAY_SIZE(nr_pages); i++) {
257 if (nr_pages[i])
258 printf("0x%016llx\t%10lu %8lu %s\t%s\n",
259 (unsigned long long)page_flags[i],
260 nr_pages[i],
261 pages2mb(nr_pages[i]),
262 page_flag_name(page_flags[i]),
263 page_flag_longname(page_flags[i]));
264 }
265
266 printf(" total\t%10lu %8lu\n",
267 total_pages, pages2mb(total_pages));
268}
269
270
271/*
272 * page flag filters
273 */
274
275int bit_mask_ok(uint64_t flags)
276{
277 int i;
278
279 for (i = 0; i < nr_bit_filters; i++) {
280 if (opt_bits[i] == KPF_ALL_BITS) {
281 if ((flags & opt_mask[i]) == 0)
282 return 0;
283 } else {
284 if ((flags & opt_mask[i]) != opt_bits[i])
285 return 0;
286 }
287 }
288
289 return 1;
290}
291
292uint64_t expand_overloaded_flags(uint64_t flags)
293{
294 /* SLOB/SLUB overload several page flags */
295 if (flags & BIT(SLAB)) {
296 if (flags & BIT(PRIVATE))
297 flags ^= BIT(PRIVATE) | BIT(SLOB_FREE);
298 if (flags & BIT(ACTIVE))
299 flags ^= BIT(ACTIVE) | BIT(SLUB_FROZEN);
300 if (flags & BIT(ERROR))
301 flags ^= BIT(ERROR) | BIT(SLUB_DEBUG);
302 }
303
304 /* PG_reclaim is overloaded as PG_readahead in the read path */
305 if ((flags & (BIT(RECLAIM) | BIT(WRITEBACK))) == BIT(RECLAIM))
306 flags ^= BIT(RECLAIM) | BIT(READAHEAD);
307
308 return flags;
309}
310
311uint64_t well_known_flags(uint64_t flags)
312{
313 /* hide flags intended only for kernel hacker */
314 flags &= ~KPF_HACKERS_BITS;
315
316 /* hide non-hugeTLB compound pages */
317 if ((flags & BITS_COMPOUND) && !(flags & BIT(HUGE)))
318 flags &= ~BITS_COMPOUND;
319
320 return flags;
321}
322
323
324/*
325 * page frame walker
326 */
327
328int hash_slot(uint64_t flags)
329{
330 int k = HASH_KEY(flags);
331 int i;
332
333 /* Explicitly reserve slot 0 for flags 0: the following logic
334 * cannot distinguish an unoccupied slot from slot (flags==0).
335 */
336 if (flags == 0)
337 return 0;
338
339 /* search through the remaining (HASH_SIZE-1) slots */
340 for (i = 1; i < ARRAY_SIZE(page_flags); i++, k++) {
341 if (!k || k >= ARRAY_SIZE(page_flags))
342 k = 1;
343 if (page_flags[k] == 0) {
344 page_flags[k] = flags;
345 return k;
346 }
347 if (page_flags[k] == flags)
348 return k;
349 }
350
351 fatal("hash table full: bump up HASH_SHIFT?\n");
352 exit(EXIT_FAILURE);
353}
354
355void add_page(unsigned long offset, uint64_t flags)
356{
357 flags = expand_overloaded_flags(flags);
358
359 if (!opt_raw)
360 flags = well_known_flags(flags);
361
362 if (!bit_mask_ok(flags))
363 return;
364
365 if (opt_list == 1)
366 show_page_range(offset, flags);
367 else if (opt_list == 2)
368 show_page(offset, flags);
369
370 nr_pages[hash_slot(flags)]++;
371 total_pages++;
372}
373
374void walk_pfn(unsigned long index, unsigned long count)
375{
376 unsigned long batch;
377 unsigned long n;
378 unsigned long i;
379
380 if (index > ULONG_MAX / KPF_BYTES)
381 fatal("index overflow: %lu\n", index);
382
383 lseek(kpageflags_fd, index * KPF_BYTES, SEEK_SET);
384
385 while (count) {
386 batch = min_t(unsigned long, count, PAGES_BATCH);
387 n = read(kpageflags_fd, kpageflags_buf, batch * KPF_BYTES);
388 if (n == 0)
389 break;
390 if (n < 0) {
391 perror(PROC_KPAGEFLAGS);
392 exit(EXIT_FAILURE);
393 }
394
395 if (n % KPF_BYTES != 0)
396 fatal("partial read: %lu bytes\n", n);
397 n = n / KPF_BYTES;
398
399 for (i = 0; i < n; i++)
400 add_page(index + i, kpageflags_buf[i]);
401
402 index += batch;
403 count -= batch;
404 }
405}
406
407void walk_addr_ranges(void)
408{
409 int i;
410
411 kpageflags_fd = open(PROC_KPAGEFLAGS, O_RDONLY);
412 if (kpageflags_fd < 0) {
413 perror(PROC_KPAGEFLAGS);
414 exit(EXIT_FAILURE);
415 }
416
417 if (!nr_addr_ranges)
418 walk_pfn(0, ULONG_MAX);
419
420 for (i = 0; i < nr_addr_ranges; i++)
421 walk_pfn(opt_offset[i], opt_size[i]);
422
423 close(kpageflags_fd);
424}
425
426
427/*
428 * user interface
429 */
430
431const char *page_flag_type(uint64_t flag)
432{
433 if (flag & KPF_HACKERS_BITS)
434 return "(r)";
435 if (flag & KPF_OVERLOADED_BITS)
436 return "(o)";
437 return " ";
438}
439
440void usage(void)
441{
442 int i, j;
443
444 printf(
445"page-types [options]\n"
446" -r|--raw Raw mode, for kernel developers\n"
447" -a|--addr addr-spec Walk a range of pages\n"
448" -b|--bits bits-spec Walk pages with specified bits\n"
449#if 0 /* planned features */
450" -p|--pid pid Walk process address space\n"
451" -f|--file filename Walk file address space\n"
452#endif
453" -l|--list Show page details in ranges\n"
454" -L|--list-each Show page details one by one\n"
455" -N|--no-summary Don't show summay info\n"
456" -h|--help Show this usage message\n"
457"addr-spec:\n"
458" N one page at offset N (unit: pages)\n"
459" N+M pages range from N to N+M-1\n"
460" N,M pages range from N to M-1\n"
461" N, pages range from N to end\n"
462" ,M pages range from 0 to M\n"
463"bits-spec:\n"
464" bit1,bit2 (flags & (bit1|bit2)) != 0\n"
465" bit1,bit2=bit1 (flags & (bit1|bit2)) == bit1\n"
466" bit1,~bit2 (flags & (bit1|bit2)) == bit1\n"
467" =bit1,bit2 flags == (bit1|bit2)\n"
468"bit-names:\n"
469 );
470
471 for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
472 if (!page_flag_names[i])
473 continue;
474 printf("%16s%s", page_flag_names[i] + 2,
475 page_flag_type(1ULL << i));
476 if (++j > 3) {
477 j = 0;
478 putchar('\n');
479 }
480 }
481 printf("\n "
482 "(r) raw mode bits (o) overloaded bits\n");
483}
484
485unsigned long long parse_number(const char *str)
486{
487 unsigned long long n;
488
489 n = strtoll(str, NULL, 0);
490
491 if (n == 0 && str[0] != '0')
492 fatal("invalid name or number: %s\n", str);
493
494 return n;
495}
496
497void parse_pid(const char *str)
498{
499 opt_pid = parse_number(str);
500}
501
502void parse_file(const char *name)
503{
504}
505
506void add_addr_range(unsigned long offset, unsigned long size)
507{
508 if (nr_addr_ranges >= MAX_ADDR_RANGES)
509 fatal("too much addr ranges\n");
510
511 opt_offset[nr_addr_ranges] = offset;
512 opt_size[nr_addr_ranges] = size;
513 nr_addr_ranges++;
514}
515
516void parse_addr_range(const char *optarg)
517{
518 unsigned long offset;
519 unsigned long size;
520 char *p;
521
522 p = strchr(optarg, ',');
523 if (!p)
524 p = strchr(optarg, '+');
525
526 if (p == optarg) {
527 offset = 0;
528 size = parse_number(p + 1);
529 } else if (p) {
530 offset = parse_number(optarg);
531 if (p[1] == '\0')
532 size = ULONG_MAX;
533 else {
534 size = parse_number(p + 1);
535 if (*p == ',') {
536 if (size < offset)
537 fatal("invalid range: %lu,%lu\n",
538 offset, size);
539 size -= offset;
540 }
541 }
542 } else {
543 offset = parse_number(optarg);
544 size = 1;
545 }
546
547 add_addr_range(offset, size);
548}
549
550void add_bits_filter(uint64_t mask, uint64_t bits)
551{
552 if (nr_bit_filters >= MAX_BIT_FILTERS)
553 fatal("too much bit filters\n");
554
555 opt_mask[nr_bit_filters] = mask;
556 opt_bits[nr_bit_filters] = bits;
557 nr_bit_filters++;
558}
559
560uint64_t parse_flag_name(const char *str, int len)
561{
562 int i;
563
564 if (!*str || !len)
565 return 0;
566
567 if (len <= 8 && !strncmp(str, "compound", len))
568 return BITS_COMPOUND;
569
570 for (i = 0; i < ARRAY_SIZE(page_flag_names); i++) {
571 if (!page_flag_names[i])
572 continue;
573 if (!strncmp(str, page_flag_names[i] + 2, len))
574 return 1ULL << i;
575 }
576
577 return parse_number(str);
578}
579
580uint64_t parse_flag_names(const char *str, int all)
581{
582 const char *p = str;
583 uint64_t flags = 0;
584
585 while (1) {
586 if (*p == ',' || *p == '=' || *p == '\0') {
587 if ((*str != '~') || (*str == '~' && all && *++str))
588 flags |= parse_flag_name(str, p - str);
589 if (*p != ',')
590 break;
591 str = p + 1;
592 }
593 p++;
594 }
595
596 return flags;
597}
598
599void parse_bits_mask(const char *optarg)
600{
601 uint64_t mask;
602 uint64_t bits;
603 const char *p;
604
605 p = strchr(optarg, '=');
606 if (p == optarg) {
607 mask = KPF_ALL_BITS;
608 bits = parse_flag_names(p + 1, 0);
609 } else if (p) {
610 mask = parse_flag_names(optarg, 0);
611 bits = parse_flag_names(p + 1, 0);
612 } else if (strchr(optarg, '~')) {
613 mask = parse_flag_names(optarg, 1);
614 bits = parse_flag_names(optarg, 0);
615 } else {
616 mask = parse_flag_names(optarg, 0);
617 bits = KPF_ALL_BITS;
618 }
619
620 add_bits_filter(mask, bits);
621}
622
623
624struct option opts[] = {
625 { "raw" , 0, NULL, 'r' },
626 { "pid" , 1, NULL, 'p' },
627 { "file" , 1, NULL, 'f' },
628 { "addr" , 1, NULL, 'a' },
629 { "bits" , 1, NULL, 'b' },
630 { "list" , 0, NULL, 'l' },
631 { "list-each" , 0, NULL, 'L' },
632 { "no-summary", 0, NULL, 'N' },
633 { "help" , 0, NULL, 'h' },
634 { NULL , 0, NULL, 0 }
635};
636
637int main(int argc, char *argv[])
638{
639 int c;
640
641 page_size = getpagesize();
642
643 while ((c = getopt_long(argc, argv,
644 "rp:f:a:b:lLNh", opts, NULL)) != -1) {
645 switch (c) {
646 case 'r':
647 opt_raw = 1;
648 break;
649 case 'p':
650 parse_pid(optarg);
651 break;
652 case 'f':
653 parse_file(optarg);
654 break;
655 case 'a':
656 parse_addr_range(optarg);
657 break;
658 case 'b':
659 parse_bits_mask(optarg);
660 break;
661 case 'l':
662 opt_list = 1;
663 break;
664 case 'L':
665 opt_list = 2;
666 break;
667 case 'N':
668 opt_no_summary = 1;
669 break;
670 case 'h':
671 usage();
672 exit(0);
673 default:
674 usage();
675 exit(1);
676 }
677 }
678
679 if (opt_list == 1)
680 printf("offset\tcount\tflags\n");
681 if (opt_list == 2)
682 printf("offset\tflags\n");
683
684 walk_addr_ranges();
685
686 if (opt_list == 1)
687 show_page_range(0, 0); /* drain the buffer */
688
689 if (opt_no_summary)
690 return 0;
691
692 if (opt_list)
693 printf("\n\n");
694
695 show_summary();
696
697 return 0;
698}