From dcfe730c60030fb76e2794a8960c6bd84c6c6163 Mon Sep 17 00:00:00 2001 From: Alex Chiang Date: Mon, 14 Dec 2009 17:57:52 -0800 Subject: [PATCH] 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: Alex Chiang Signed-off-by: Wu Fengguang Cc: Andi Kleen Cc: Haicheng Li Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/vm/page-types.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/Documentation/vm/page-types.c b/Documentation/vm/page-types.c index 2279b616a7ac..8c28be6a47cb 100644 --- a/Documentation/vm/page-types.c +++ b/Documentation/vm/page-types.c @@ -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; -- 2.20.1