gnome-terminal never returns after heavy load btrfs operations (defragment, balance, etc.)

[Karl-Philipp Richter]

Running `btrfs` commands which cause heavy system load (e.g. `btrfs filesystem defragment`, `btrfs balance`, etc.) in `gnome-terminal` causes the terminal never to return and use one CPU core at 100 % forever. There's no connection to the system load because interrupting that command (e.g. `btrfs filesystem defragment` with `SIGSTOP`) don't make `gnome-terminal` return, but keep hanging forever.

ProblemType: Bug
DistroRelease: Ubuntu 14.10
Package: gnome-terminal 3.6.2-0ubuntu1
Uname: Linux 3.19.2-031902-generic x86_64
ApportVersion: 2.14.7-0ubuntu8.2
Architecture: amd64
CurrentDesktop: Unity
Date: Sat Mar 28 23:00:56 2015
EcryptfsInUse: Yes
InstallationDate: Installed on 2015-01-26 (60 days ago)
InstallationMedia: Ubuntu 14.10 "Utopic Unicorn" - Release amd64 (20141022.1)
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: gnome-terminal
UpgradeStatus: No upgrade log present (probably fresh install)

[Egmont Koblinger (egmont-gmail)]

Could this be another manifestation of https://bugzilla.gnome.org/show_bug.cgi?id=735101 ? It's another case of gnome-terminal using 100% CPU, and unfortunately we're stuck and ran out of ideas.

The next time it happens, could you connect to gnome-terminal with strace (e.g. from an xterm) and see if it's stuck in a loop, like in that bugreport?

How often can you reproduce this problem? (The main reason we can't debug the upstream bug is that it happens once in every couple of months, we can't force reproduce it.)

[Karl-Philipp Richter (krichter722)]

Thanks for you feedback. I guess, I could get it up to once a week (using an overful btrfs root system on which the btrfs command cause a very high load) ;) . I'll figure out `strace` and try to share results.

[Egmont Koblinger (egmont-gmail)]

This bug was located and fixed in Gtk+ (follow the link I posted above), and the fix (https://git.gnome.org/browse/gtk+/commit/?id=561ff51a) made it to Vivid. Ubuntu folks should backport it to Trusty too.