Re: [RFC] Prepend timestamp in msgbuf

Alexander Best <arundel_at_freebsd.org> writes:

>> On Fri Oct 14 11, Poul-Henning Kamp wrote:
>> > In message <20111014085609.GA3799_at_freebsd.org>, Alexander Best writes:
>> > 
>> > >1) would it be possible to prepend those timestamps to the actual console
>> > >output and not only to the output of demsg? maybe via a sysctl toggle?
>> > 
>> > The kernel does not know enough about timezones to emit anything
>> > but UTC timestamps.
>> 
>> hmm ok.
>> 
>> > 
>> > >2) my dmesg output contains a lot of these entries: "<118>"
>> > 
>> > These are magic markers for syslogd(8) specifying priority.
>> 
>> it would be nice, if their output could be turned off via a dmesg flag imo.
>> 
>> > 
>> > >3) roughly the first 30 lines of my dmesg output have the timestamp "[1.0]".
>> > >would it be possible to have more accuracy there?
>> > 
>> > No, because we don't know the time until we've found the RTC chip.
>> 
>> maybe prepending the output with [??] instead of [1.0] would make more sense,
>> so users knows that those timestamps are bogus.
>
> maybe the granularity of the timestamps could be limited to a static value? the
> following output doesn't really look pretty:
>
> [7.729516] <118>/dev/ufs/varfs: clean, 879143 free (7407 frags, 108967 blocks, 0.7% fragmentation)
> [7.891512] <118>Mounting local file systems:WARNING: TMPFS is considered to be a highly experimental feature in FreeBSD.
> [8.33519] .
> [9.440514] <118>Setting hostname: otaku.
> [9.744516] wlan0: Ethernet address: 00:0f:b5:82:07:c8
> [9.850516] <118>Starting wpa_supplicant.
> [10.335514] <118>Starting Network: lo0 ath0.
>
> so it would be nice, if trailing zeros got printed out, too.

Why not make formatting similar to linux/xorg logs, e.g.

  [    31.897] (**) Option "XkbLayout" "us"
  [    31.897] (II) XINPUT: Adding extended input device "<default keyboard>" (type: KEYBOARD, id 7)
  [ 11485.404] (II) 3rd Button detected: disabling emulate3Button

  [    0.000000] Linux version 3.0-ARCH (tobias_at_T-POWA-LX) (gcc version 4.6.1 20110819 (prerelease) (GCC) ) #1 SMP PREEMPT Tue Aug 30 08:53:25 CEST 2011
  [    0.000000] Command line: root=/dev/disk/by-uuid/625db1f5-9b51-4d2d-acb7-6726f4d7e199 ro
  [...]
  [   15.096862] NET: Registered protocol family 10
  [   16.792594] [drm] nouveau 0000:01:00.0: plugged DVI-I-2
  [   26.054186] eth0: no IPv6 routers present

A way to convert those timestamps to localtime or time delta[1] post-mortem
via dmesg(8) would be good, too.

[1] like in tcpdump -ttt