Commit dcfe730c authored by Alex Chiang's avatar Alex Chiang Committed by Linus Torvalds

page-types: learn to describe flags directly from command line

Teach page-types to describe page flags directly from the command line.

Why is this useful?  For instance, if you're using memory hotplug and see
this in /var/log/messages:

	kernel: removing from LRU failed 3836dd0/1/1e00000000000010

It would be nice to decode those page flags without staring at the source.

Example usage and output:

# Documentation/vm/page-types -d 0x10
0x0000000000000010	____D_____________________________	dirty

# Documentation/vm/page-types -d anon
0x0000000000001000	____________a_____________________	anonymous

# Documentation/vm/page-types -d anon,0x10
0x0000000000001010	____D_______a_____________________	dirty,anonymous

[achiang@hp.com: documentation]
Signed-off-by: default avatarAlex Chiang <achiang@hp.com>
Signed-off-by: default avatarWu Fengguang <fengguang.wu@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Haicheng Li <haicheng.li@intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent f1327bf1
......@@ -674,6 +674,7 @@ static void usage(void)
printf(
"page-types [options]\n"
" -r|--raw Raw mode, for kernel developers\n"
" -d|--describe flags Describe flags\n"
" -a|--addr addr-spec Walk a range of pages\n"
" -b|--bits bits-spec Walk pages with specified bits\n"
" -p|--pid pid Walk process address space\n"
......@@ -686,6 +687,10 @@ static void usage(void)
" -X|--hwpoison hwpoison pages\n"
" -x|--unpoison unpoison pages\n"
" -h|--help Show this usage message\n"
"flags:\n"
" 0x10 bitfield format, e.g.\n"
" anon bit-name, e.g.\n"
" 0x10,anon comma-separated list, e.g.\n"
"addr-spec:\n"
" N one page at offset N (unit: pages)\n"
" N+M pages range from N to N+M-1\n"
......@@ -884,6 +889,15 @@ static void parse_bits_mask(const char *optarg)
add_bits_filter(mask, bits);
}
static void describe_flags(const char *optarg)
{
uint64_t flags = parse_flag_names(optarg, 0);
printf("0x%016llx\t%s\t%s\n",
(unsigned long long)flags,
page_flag_name(flags),
page_flag_longname(flags));
}
static const struct option opts[] = {
{ "raw" , 0, NULL, 'r' },
......@@ -891,6 +905,7 @@ static const struct option opts[] = {
{ "file" , 1, NULL, 'f' },
{ "addr" , 1, NULL, 'a' },
{ "bits" , 1, NULL, 'b' },
{ "describe" , 1, NULL, 'd' },
{ "list" , 0, NULL, 'l' },
{ "list-each" , 0, NULL, 'L' },
{ "no-summary", 0, NULL, 'N' },
......@@ -907,7 +922,7 @@ int main(int argc, char *argv[])
page_size = getpagesize();
while ((c = getopt_long(argc, argv,
"rp:f:a:b:lLNXxh", opts, NULL)) != -1) {
"rp:f:a:b:d:lLNXxh", opts, NULL)) != -1) {
switch (c) {
case 'r':
opt_raw = 1;
......@@ -924,6 +939,10 @@ int main(int argc, char *argv[])
case 'b':
parse_bits_mask(optarg);
break;
case 'd':
opt_no_summary = 1;
describe_flags(optarg);
break;
case 'l':
opt_list = 1;
break;
......
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