Re: Reducing SIGINFO verbosity

From: Conrad Meyer <cem_at_freebsd.org>
Date: Thu, 20 May 2021 22:57:17 UTC
No, I don’t think there’s any reason to default it differently on stable vs
current. I think it’s useful (and I prefer the more verbose form, which
isn’t the default).

Conrad

On Thu, May 20, 2021 at 11:59 John-Mark Gurney <jmg@funkthat.com> wrote:

> Michael Gmelin wrote this message on Thu, May 20, 2021 at 18:01 +0200:
> > I'm leaving this here, mostly so that others (or future me) can google
> > it up.
> >
> > Traditionally, CTRL-t would give a one-line output + whatever the
> > process specific signal handler comes up with:
> >
> >   # sleep 120 <--- hits CTRL-t
> >   load: 0.27  cmd: sleep 38162 [nanslp] 0.64r 0.00u 0.00s 0% 1780k
> >   sleep: about 119 second(s) left out of the original 120
> >
> >   # cat <--- hits CTRL-t
> >   load: 0.02  cmd: cat 24379 [ttyin] 0.63r 0.00u 0.00s 0% 2308k
> >
> >
> > On 13 I get:
> >
> >   # sleep 120 <--- hits CTRL-t
> >   load: 0.12  cmd: sleep 3241 [nanslp] 0.52r 0.00u 0.00s 0% 2172k
> >   mi_switch+0xc1 sleepq_catch_signals+0x2e6 sleepq_timedwait_sig+0x12
> >   _sleep+0x199 kern_clock_nanosleep+0x1e1 sys_nanosleep+0x3b
> >   amd64_syscall+0x10c fast_syscall_common+0xf8 sleep: about 119
> >   second(s) left out of the original 120
> >
> >   # cat <--- hits CTRL-t
> >   load: 0.09  cmd: cat 3240 [ttyin] 0.23r 0.00u 0.00s 0% 2300k
> >   mi_switch+0xc1 sleepq_catch_signals+0x2e6 sleepq_wait_sig+0x9
> >   _cv_wait_sig+0xe4 tty_wait+0x1c ttydisc_read+0x2ac ttydev_read+0x56
> >   devfs_read_f+0xd5 dofileread+0x81 sys_read+0xbc amd64_syscall+0x10c
> >   fast_syscall_common+0xf8
> >
> > which is quite way too verbose when checking the progress of
> > long-running processes, like cp, dd, or poudriere. Especially as CTRL-t
> > is part of the user experience to me - I use it to interact with the
> > machine outside of debugging software issues.
> >
> > Setting
> >
> >   sysctl kern.tty_info_kstacks=0
> >   echo kern.tty_info_kstacks=0 >>/etc/sysctl.conf
> >
> > fixes this permanently.
> >
> > Apparently, this was enabled by default on purpose[0], so that people
> > find the feature (which certainly worked ^_^), but I think it would
> > been worth mentioning the sysctl somewhere in the release notes/errata,
> > so that people understand how to disable it again.
>
> I think the original intent was to disable this on -stable or at least
> -RELEASEs, but it looks like this didn't happen.  This is VERY helpful
> for a developer, but not as helpful for most users.
>
> Conrad,
>
> Should this be disabled on -stable now?
>
> --
>   John-Mark Gurney                              Voice: +1 415 225 5579
>
>      "All that I will do, has been done, All that I have, has not."
>