Bug 185156 - Graphical console on 10-RC locks up on heavy writing
Summary: Graphical console on 10-RC locks up on heavy writing
Status: Open
Alias: None
Product: Base System
Classification: Unclassified
Component: misc (show other bugs)
Version: Unspecified
Hardware: Any Any
: Normal Affects Only Me
Assignee: freebsd-bugs (Nobody)
Depends on:
Reported: 2013-12-24 13:50 UTC by Mark Martinec
Modified: 2017-12-31 22:27 UTC (History)
0 users

See Also:


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Description Mark Martinec 2013-12-24 13:50:00 UTC
Copying a topic from the freebsd-stable ML:
submitted here so as not to be forgotten:

Mark Martinec wrote on 2013-12-23:

FreeBSD amd64, recent stable/10:
When running some task on a graphical console window
and that task writes lots of output to a console, the
console gets stuck after some time (like 20 minutes),
output stops, keyboard appears unresponsive, alt-ctrl-Fn
is unable to switch consoles - but the machine seems
otherwise sane: I can log in over ssh, file system and
processes are healthy, CPU not busy.

This was first noticed trying to rebuild kde from
ports in a console window. Same happened when bulk
updating packages from a remote site and the pkg update
was busily writing its output to a console.

The same heavy tasks (e.g. ports rebuild) can run
just fine in an ssh session, or in a konsole / xterm.

As a final proof, I tried a perl one-liner which
writes a line (a count and some text) ten times per
second: it manages to screw up the console window
in about 6 minutes.

Interestingly, while the console output is stuck
and I blindly type a command on a keyboard (no echo),
then run a shutdown from another (ssh) session,
the console output gets unstuck during shutdown,
rapidly displays the missing lines, including the
echo of a command typed blindly previously, along
with its output.

Btw, this never happened on this machine while it was
running 9.2 or older versions.

Adrian Chadd wrote on 2013-12-23:

I see this when the kernel is outputting debugging .. the console can
quickly lock up exactly how you describe. I've never figured out why
though. :(

How-To-Repeat: On a console run any program that writes lots of output,
e.g. the following perl one-liner:

perl -e '@a=("a".."z","0".."9"); for (;;) {
  printf("%d %s %s\n", ++$n, join("",@a), scalar localtime);
  push(@a, shift @a); select(undef,undef,undef,0.1) }'
Comment 1 Eitan Adler freebsd_committer freebsd_triage 2017-12-31 08:01:16 UTC
For bugs matching the following criteria:

Status: In Progress Changed: (is less than) 2014-06-01

Reset to default assignee and clear in-progress tags.

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