Re: [Crash-utility] [PATCH] log: add warning to help text to inform the inaccuracy of -T option

Date: Tue, 16 Nov 2021 02:42:23 +0000 From: HAGIO KAZUHITO(?????) <k-hagio-ab(a)nec.com&gt; To: lijiang <lijiang(a)redhat.com&gt; Cc: "Discussion list for crash utility usage, maintenance and development" <crash-utility(a)redhat.com&gt; Subject: [Crash-utility] [PATCH] log: add warning to help text to inform the inaccuracy of -T option Message-ID: < TYYPR01MB6777010CB098495B9FE1E521DD999(a)TYYPR01MB6777.jpnprd01.prod.outlook.com > Content-Type: text/plain; charset="iso-2022-jp" The timestamps of the "log -T" option are inaccurate because they are from local_clock(), which returns the raw counter in the local CPU and it's different from the elapsed wall time. (See [1] for details) The dmesg command, which the "log -T" option imitates, has a similar behavior in nature and a warning in its help text. Let's add a warning also to the crash's help text to inform the inaccuracy for now. [1] https://listman.redhat.com/archives/crash-utility/2021-September/msg00044... Reported-by: Martin Moore <martin.moore(a)hpe.com&gt; Signed-off-by: Kazuhito Hagio <k-hagio-ab(a)nec.com&gt; ---

1 file changed, 2 insertions(+) diff --git a/help.c b/help.c index c19b69b8b20c..04a7effd0534 100644 --- a/help.c +++ b/help.c @@ -3893,6 +3893,8 @@ char *help_log[] = { " record format, where the timestamp is contained in each log entry's header.", " ", " -T Display the message text with human readable timestamp.", +" (Be aware that the timestamp could be inaccurate! The timestamp is", +" from local_clock(), which is different from the elapsed wall time.)", " -t Display the message text without the timestamp; only applicable to the", " variable-length record format.", " -d Display the dictionary of key/value pair properties that are optionally", -- 2.27.0