Commit 35efa5e9 authored by Wu Fengguang's avatar Wu Fengguang Committed by Linus Torvalds

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: default avatarWu 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 17e89501
...@@ -2,7 +2,7 @@ ...@@ -2,7 +2,7 @@
obj- := dummy.o obj- := dummy.o
# List of programs to build # List of programs to build
hostprogs-y := slabinfo hostprogs-y := slabinfo slqbinfo page-types
# Tell kbuild to always build the programs # Tell kbuild to always build the programs
always := $(hostprogs-y) always := $(hostprogs-y)
/*
* page-types: Tool for querying page flags
*
* Copyright (C) 2009 Intel corporation
* Copyright (C) 2009 Wu Fengguang <fengguang.wu@intel.com>
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdint.h>
#include <stdarg.h>
#include <string.h>
#include <getopt.h>
#include <limits.h>
#include <sys/types.h>
#include <sys/errno.h>
#include <sys/fcntl.h>
/*
* kernel page flags
*/
#define KPF_BYTES 8
#define PROC_KPAGEFLAGS "/proc/kpageflags"
/* copied from kpageflags_read() */
#define KPF_LOCKED 0
#define KPF_ERROR 1
#define KPF_REFERENCED 2
#define KPF_UPTODATE 3
#define KPF_DIRTY 4
#define KPF_LRU 5
#define KPF_ACTIVE 6
#define KPF_SLAB 7
#define KPF_WRITEBACK 8
#define KPF_RECLAIM 9
#define KPF_BUDDY 10
/* [11-20] new additions in 2.6.31 */
#define KPF_MMAP 11
#define KPF_ANON 12
#define KPF_SWAPCACHE 13
#define KPF_SWAPBACKED 14
#define KPF_COMPOUND_HEAD 15
#define KPF_COMPOUND_TAIL 16
#define KPF_HUGE 17
#define KPF_UNEVICTABLE 18
#define KPF_NOPAGE 20
/* [32-] kernel hacking assistances */
#define KPF_RESERVED 32
#define KPF_MLOCKED 33
#define KPF_MAPPEDTODISK 34
#define KPF_PRIVATE 35
#define KPF_PRIVATE_2 36
#define KPF_OWNER_PRIVATE 37
#define KPF_ARCH 38
#define KPF_UNCACHED 39
/* [48-] take some arbitrary free slots for expanding overloaded flags
* not part of kernel API
*/
#define KPF_READAHEAD 48
#define KPF_SLOB_FREE 49
#define KPF_SLUB_FROZEN 50
#define KPF_SLUB_DEBUG 51
#define KPF_ALL_BITS ((uint64_t)~0ULL)
#define KPF_HACKERS_BITS (0xffffULL << 32)
#define KPF_OVERLOADED_BITS (0xffffULL << 48)
#define BIT(name) (1ULL << KPF_##name)
#define BITS_COMPOUND (BIT(COMPOUND_HEAD) | BIT(COMPOUND_TAIL))
static char *page_flag_names[] = {
[KPF_LOCKED] = "L:locked",
[KPF_ERROR] = "E:error",
[KPF_REFERENCED] = "R:referenced",
[KPF_UPTODATE] = "U:uptodate",
[KPF_DIRTY] = "D:dirty",
[KPF_LRU] = "l:lru",
[KPF_ACTIVE] = "A:active",
[KPF_SLAB] = "S:slab",
[KPF_WRITEBACK] = "W:writeback",
[KPF_RECLAIM] = "I:reclaim",
[KPF_BUDDY] = "B:buddy",
[KPF_MMAP] = "M:mmap",
[KPF_ANON] = "a:anonymous",
[KPF_SWAPCACHE] = "s:swapcache",
[KPF_SWAPBACKED] = "b:swapbacked",
[KPF_COMPOUND_HEAD] = "H:compound_head",
[KPF_COMPOUND_TAIL] = "T:compound_tail",
[KPF_HUGE] = "G:huge",
[KPF_UNEVICTABLE] = "u:unevictable",
[KPF_NOPAGE] = "n:nopage",
[KPF_RESERVED] = "r:reserved",
[KPF_MLOCKED] = "m:mlocked",
[KPF_MAPPEDTODISK] = "d:mappedtodisk",
[KPF_PRIVATE] = "P:private",
[KPF_PRIVATE_2] = "p:private_2",
[KPF_OWNER_PRIVATE] = "O:owner_private",
[KPF_ARCH] = "h:arch",
[KPF_UNCACHED] = "c:uncached",
[KPF_READAHEAD] = "I:readahead",
[KPF_SLOB_FREE] = "P:slob_free",
[KPF_SLUB_FROZEN] = "A:slub_frozen",
[KPF_SLUB_DEBUG] = "E:slub_debug",
};
/*
* data structures
*/
static int opt_raw; /* for kernel developers */
static int opt_list; /* list pages (in ranges) */
static int opt_no_summary; /* don't show summary */
static pid_t opt_pid; /* process to walk */
#define MAX_ADDR_RANGES 1024
static int nr_addr_ranges;
static unsigned long opt_offset[MAX_ADDR_RANGES];
static unsigned long opt_size[MAX_ADDR_RANGES];
#define MAX_BIT_FILTERS 64
static int nr_bit_filters;
static uint64_t opt_mask[MAX_BIT_FILTERS];
static uint64_t opt_bits[MAX_BIT_FILTERS];
static int page_size;
#define PAGES_BATCH (64 << 10) /* 64k pages */
static int kpageflags_fd;
static uint64_t kpageflags_buf[KPF_BYTES * PAGES_BATCH];
#define HASH_SHIFT 13
#define HASH_SIZE (1 << HASH_SHIFT)
#define HASH_MASK (HASH_SIZE - 1)
#define HASH_KEY(flags) (flags & HASH_MASK)
static unsigned long total_pages;
static unsigned long nr_pages[HASH_SIZE];
static uint64_t page_flags[HASH_SIZE];
/*
* helper functions
*/
#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
#define min_t(type, x, y) ({ \
type __min1 = (x); \
type __min2 = (y); \
__min1 < __min2 ? __min1 : __min2; })
unsigned long pages2mb(unsigned long pages)
{
return (pages * page_size) >> 20;
}
void fatal(const char *x, ...)
{
va_list ap;
va_start(ap, x);
vfprintf(stderr, x, ap);
va_end(ap);
exit(EXIT_FAILURE);
}
/*
* page flag names
*/
char *page_flag_name(uint64_t flags)
{
static char buf[65];
int present;
int i, j;
for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
present = (flags >> i) & 1;
if (!page_flag_names[i]) {
if (present)
fatal("unkown flag bit %d\n", i);
continue;
}
buf[j++] = present ? page_flag_names[i][0] : '_';
}
return buf;
}
char *page_flag_longname(uint64_t flags)
{
static char buf[1024];
int i, n;
for (i = 0, n = 0; i < ARRAY_SIZE(page_flag_names); i++) {
if (!page_flag_names[i])
continue;
if ((flags >> i) & 1)
n += snprintf(buf + n, sizeof(buf) - n, "%s,",
page_flag_names[i] + 2);
}
if (n)
n--;
buf[n] = '\0';
return buf;
}
/*
* page list and summary
*/
void show_page_range(unsigned long offset, uint64_t flags)
{
static uint64_t flags0;
static unsigned long index;
static unsigned long count;
if (flags == flags0 && offset == index + count) {
count++;
return;
}
if (count)
printf("%lu\t%lu\t%s\n",
index, count, page_flag_name(flags0));
flags0 = flags;
index = offset;
count = 1;
}
void show_page(unsigned long offset, uint64_t flags)
{
printf("%lu\t%s\n", offset, page_flag_name(flags));
}
void show_summary(void)
{
int i;
printf(" flags\tpage-count MB"
" symbolic-flags\t\t\tlong-symbolic-flags\n");
for (i = 0; i < ARRAY_SIZE(nr_pages); i++) {
if (nr_pages[i])
printf("0x%016llx\t%10lu %8lu %s\t%s\n",
(unsigned long long)page_flags[i],
nr_pages[i],
pages2mb(nr_pages[i]),
page_flag_name(page_flags[i]),
page_flag_longname(page_flags[i]));
}
printf(" total\t%10lu %8lu\n",
total_pages, pages2mb(total_pages));
}
/*
* page flag filters
*/
int bit_mask_ok(uint64_t flags)
{
int i;
for (i = 0; i < nr_bit_filters; i++) {
if (opt_bits[i] == KPF_ALL_BITS) {
if ((flags & opt_mask[i]) == 0)
return 0;
} else {
if ((flags & opt_mask[i]) != opt_bits[i])
return 0;
}
}
return 1;
}
uint64_t expand_overloaded_flags(uint64_t flags)
{
/* SLOB/SLUB overload several page flags */
if (flags & BIT(SLAB)) {
if (flags & BIT(PRIVATE))
flags ^= BIT(PRIVATE) | BIT(SLOB_FREE);
if (flags & BIT(ACTIVE))
flags ^= BIT(ACTIVE) | BIT(SLUB_FROZEN);
if (flags & BIT(ERROR))
flags ^= BIT(ERROR) | BIT(SLUB_DEBUG);
}
/* PG_reclaim is overloaded as PG_readahead in the read path */
if ((flags & (BIT(RECLAIM) | BIT(WRITEBACK))) == BIT(RECLAIM))
flags ^= BIT(RECLAIM) | BIT(READAHEAD);
return flags;
}
uint64_t well_known_flags(uint64_t flags)
{
/* hide flags intended only for kernel hacker */
flags &= ~KPF_HACKERS_BITS;
/* hide non-hugeTLB compound pages */
if ((flags & BITS_COMPOUND) && !(flags & BIT(HUGE)))
flags &= ~BITS_COMPOUND;
return flags;
}
/*
* page frame walker
*/
int hash_slot(uint64_t flags)
{
int k = HASH_KEY(flags);
int i;
/* Explicitly reserve slot 0 for flags 0: the following logic
* cannot distinguish an unoccupied slot from slot (flags==0).
*/
if (flags == 0)
return 0;
/* search through the remaining (HASH_SIZE-1) slots */
for (i = 1; i < ARRAY_SIZE(page_flags); i++, k++) {
if (!k || k >= ARRAY_SIZE(page_flags))
k = 1;
if (page_flags[k] == 0) {
page_flags[k] = flags;
return k;
}
if (page_flags[k] == flags)
return k;
}
fatal("hash table full: bump up HASH_SHIFT?\n");
exit(EXIT_FAILURE);
}
void add_page(unsigned long offset, uint64_t flags)
{
flags = expand_overloaded_flags(flags);
if (!opt_raw)
flags = well_known_flags(flags);
if (!bit_mask_ok(flags))
return;
if (opt_list == 1)
show_page_range(offset, flags);
else if (opt_list == 2)
show_page(offset, flags);
nr_pages[hash_slot(flags)]++;
total_pages++;
}
void walk_pfn(unsigned long index, unsigned long count)
{
unsigned long batch;
unsigned long n;
unsigned long i;
if (index > ULONG_MAX / KPF_BYTES)
fatal("index overflow: %lu\n", index);
lseek(kpageflags_fd, index * KPF_BYTES, SEEK_SET);
while (count) {
batch = min_t(unsigned long, count, PAGES_BATCH);
n = read(kpageflags_fd, kpageflags_buf, batch * KPF_BYTES);
if (n == 0)
break;
if (n < 0) {
perror(PROC_KPAGEFLAGS);
exit(EXIT_FAILURE);
}
if (n % KPF_BYTES != 0)
fatal("partial read: %lu bytes\n", n);
n = n / KPF_BYTES;
for (i = 0; i < n; i++)
add_page(index + i, kpageflags_buf[i]);
index += batch;
count -= batch;
}
}
void walk_addr_ranges(void)
{
int i;
kpageflags_fd = open(PROC_KPAGEFLAGS, O_RDONLY);
if (kpageflags_fd < 0) {
perror(PROC_KPAGEFLAGS);
exit(EXIT_FAILURE);
}
if (!nr_addr_ranges)
walk_pfn(0, ULONG_MAX);
for (i = 0; i < nr_addr_ranges; i++)
walk_pfn(opt_offset[i], opt_size[i]);
close(kpageflags_fd);
}
/*
* user interface
*/
const char *page_flag_type(uint64_t flag)
{
if (flag & KPF_HACKERS_BITS)
return "(r)";
if (flag & KPF_OVERLOADED_BITS)
return "(o)";
return " ";
}
void usage(void)
{
int i, j;
printf(
"page-types [options]\n"
" -r|--raw Raw mode, for kernel developers\n"
" -a|--addr addr-spec Walk a range of pages\n"
" -b|--bits bits-spec Walk pages with specified bits\n"
#if 0 /* planned features */
" -p|--pid pid Walk process address space\n"
" -f|--file filename Walk file address space\n"
#endif
" -l|--list Show page details in ranges\n"
" -L|--list-each Show page details one by one\n"
" -N|--no-summary Don't show summay info\n"
" -h|--help Show this usage message\n"
"addr-spec:\n"
" N one page at offset N (unit: pages)\n"
" N+M pages range from N to N+M-1\n"
" N,M pages range from N to M-1\n"
" N, pages range from N to end\n"
" ,M pages range from 0 to M\n"
"bits-spec:\n"
" bit1,bit2 (flags & (bit1|bit2)) != 0\n"
" bit1,bit2=bit1 (flags & (bit1|bit2)) == bit1\n"
" bit1,~bit2 (flags & (bit1|bit2)) == bit1\n"
" =bit1,bit2 flags == (bit1|bit2)\n"
"bit-names:\n"
);
for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
if (!page_flag_names[i])
continue;
printf("%16s%s", page_flag_names[i] + 2,
page_flag_type(1ULL << i));
if (++j > 3) {
j = 0;
putchar('\n');
}
}
printf("\n "
"(r) raw mode bits (o) overloaded bits\n");
}
unsigned long long parse_number(const char *str)
{
unsigned long long n;
n = strtoll(str, NULL, 0);
if (n == 0 && str[0] != '0')
fatal("invalid name or number: %s\n", str);
return n;
}
void parse_pid(const char *str)
{
opt_pid = parse_number(str);
}
void parse_file(const char *name)
{
}
void add_addr_range(unsigned long offset, unsigned long size)
{
if (nr_addr_ranges >= MAX_ADDR_RANGES)
fatal("too much addr ranges\n");
opt_offset[nr_addr_ranges] = offset;
opt_size[nr_addr_ranges] = size;
nr_addr_ranges++;
}
void parse_addr_range(const char *optarg)
{
unsigned long offset;
unsigned long size;
char *p;
p = strchr(optarg, ',');
if (!p)
p = strchr(optarg, '+');
if (p == optarg) {
offset = 0;
size = parse_number(p + 1);
} else if (p) {
offset = parse_number(optarg);
if (p[1] == '\0')
size = ULONG_MAX;
else {
size = parse_number(p + 1);
if (*p == ',') {
if (size < offset)
fatal("invalid range: %lu,%lu\n",
offset, size);
size -= offset;
}
}
} else {
offset = parse_number(optarg);
size = 1;
}
add_addr_range(offset, size);
}
void add_bits_filter(uint64_t mask, uint64_t bits)
{
if (nr_bit_filters >= MAX_BIT_FILTERS)
fatal("too much bit filters\n");
opt_mask[nr_bit_filters] = mask;
opt_bits[nr_bit_filters] = bits;
nr_bit_filters++;
}
uint64_t parse_flag_name(const char *str, int len)
{
int i;
if (!*str || !len)
return 0;
if (len <= 8 && !strncmp(str, "compound", len))
return BITS_COMPOUND;
for (i = 0; i < ARRAY_SIZE(page_flag_names); i++) {
if (!page_flag_names[i])
continue;
if (!strncmp(str, page_flag_names[i] + 2, len))
return 1ULL << i;
}
return parse_number(str);
}
uint64_t parse_flag_names(const char *str, int all)
{
const char *p = str;
uint64_t flags = 0;
while (1) {
if (*p == ',' || *p == '=' || *p == '\0') {
if ((*str != '~') || (*str == '~' && all && *++str))
flags |= parse_flag_name(str, p - str);
if (*p != ',')
break;
str = p + 1;
}
p++;
}
return flags;
}
void parse_bits_mask(const char *optarg)
{
uint64_t mask;
uint64_t bits;
const char *p;
p = strchr(optarg, '=');
if (p == optarg) {
mask = KPF_ALL_BITS;
bits = parse_flag_names(p + 1, 0);
} else if (p) {
mask = parse_flag_names(optarg, 0);
bits = parse_flag_names(p + 1, 0);
} else if (strchr(optarg, '~')) {
mask = parse_flag_names(optarg, 1);
bits = parse_flag_names(optarg, 0);
} else {
mask = parse_flag_names(optarg, 0);
bits = KPF_ALL_BITS;
}
add_bits_filter(mask, bits);
}
struct option opts[] = {
{ "raw" , 0, NULL, 'r' },
{ "pid" , 1, NULL, 'p' },
{ "file" , 1, NULL, 'f' },
{ "addr" , 1, NULL, 'a' },
{ "bits" , 1, NULL, 'b' },
{ "list" , 0, NULL, 'l' },
{ "list-each" , 0, NULL, 'L' },
{ "no-summary", 0, NULL, 'N' },
{ "help" , 0, NULL, 'h' },
{ NULL , 0, NULL, 0 }
};
int main(int argc, char *argv[])
{
int c;
page_size = getpagesize();
while ((c = getopt_long(argc, argv,
"rp:f:a:b:lLNh", opts, NULL)) != -1) {
switch (c) {
case 'r':
opt_raw = 1;
break;
case 'p':
parse_pid(optarg);
break;
case 'f':
parse_file(optarg);
break;
case 'a':
parse_addr_range(optarg);
break;
case 'b':
parse_bits_mask(optarg);
break;
case 'l':
opt_list = 1;
break;
case 'L':
opt_list = 2;
break;
case 'N':
opt_no_summary = 1;
break;
case 'h':
usage();
exit(0);
default:
usage();
exit(1);
}
}
if (opt_list == 1)
printf("offset\tcount\tflags\n");
if (opt_list == 2)
printf("offset\tflags\n");
walk_addr_ranges();
if (opt_list == 1)
show_page_range(0, 0); /* drain the buffer */
if (opt_no_summary)
return 0;
if (opt_list)
printf("\n\n");
show_summary();
return 0;
}
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