Date: Thu, 20 May 2021 11:59:17 -0700 From: John-Mark Gurney <jmg@funkthat.com> To: Michael Gmelin <freebsd@grem.de> Cc: "freebsd-current@freebsd.org" <freebsd-current@freebsd.org>, cem@FreeBSD.org Subject: Re: Reducing SIGINFO verbosity Message-ID: <20210520185917.GL14975@funkthat.com> In-Reply-To: <20210520180155.3e23500e@bsd64.grem.de> References: <20210520180155.3e23500e@bsd64.grem.de>
next in thread | previous in thread | raw e-mail | index | archive | help
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."
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20210520185917.GL14975>