# Workaround? Tried once, works. TL;DR: reading the slave pts from another process unfreezes and allows continued operation
cd /proc/24621/fd ls -al total 0 dr-x------ 2 stephane stephane 0 avril 5 16:39 . dr-xr-xr-x 9 stephane stephane 0 avril 5 15:13 .. lrwx------ 1 stephane stephane 64 avril 5 16:56 0 -> /dev/pts/8 lrwx------ 1 stephane stephane 64 avril 5 16:56 1 -> /dev/pts/8 lrwx------ 1 stephane stephane 64 avril 5 16:39 2 -> /dev/pts/8 lrwx------ 1 stephane stephane 64 avril 5 16:56 3 -> /dev/ptmx lrwx------ 1 stephane stephane 64 avril 5 16:56 4 -> /dev/pts/20 lrwx------ 1 stephane stephane 64 avril 5 16:56 5 -> anon_inode:[signalfd] l-wx------ 1 stephane stephane 64 avril 5 16:56 6 -> /home/stephane/typescript (deleted) So, pts/8 is the master, pts/20 is the slave. echo foo >/dev/pts/8 -> This shows "foo" in the terminal window. head -n 1 /dev/pts/8 ^C This blocks my shell, so I do Ctrl-C to regain. echo foo >/dev/pts/20 This blocks my shell, so I do Ctrl-C to regain. ^Cbash: echo: erreur d'écriture : Appel système interrompu This one is interesting: head -n 1 /dev/pts/20 It does not block, and works around the bug immediately. I'll try again. ** Tags added: has-workaround regression-release reproducible -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to util-linux in Ubuntu. https://bugs.launchpad.net/bugs/1558236 Title: /usr/bin/script freezes and eats all CPU, has to be killed, which kills shell and programs inside Status in util-linux package in Ubuntu: New Bug description: # Context I've been using /usr/bin/script quite a lot for about 4 years (since about Ubuntu 12.04, maybe before). It always worked without problem. I'm using several script instance most of the time, in several terminals. Reproducible: randomly, once every few days. Problem happens since Ubuntu 16.04. Never seen before (12.04 12.10 13.04 13.10 14.04 14.10 15.04 15.10). # Expected Continued operation, terminal running programs normally, little CPU used. # Observed Suddenly, terminal freezes. Other tabs of same terminal window not affected. Top shows script consumes 100% CPU. Strace shows an endless stream of this line: poll([{fd=4, events=POLLIN}], 1, 10) = 1 ([{fd=4, revents=POLLIN}]) /proc/*/fd shows what file descriptor it is: total 0 dr-x------ 2 stephane stephane 0 mars 16 20:03 . dr-xr-xr-x 9 stephane stephane 0 mars 16 20:03 .. lrwx------ 1 stephane stephane 64 mars 16 20:15 0 -> /dev/pts/17 (deleted) lrwx------ 1 stephane stephane 64 mars 16 20:15 1 -> /dev/pts/17 (deleted) lrwx------ 1 stephane stephane 64 mars 16 20:03 2 -> /dev/pts/17 (deleted) lrwx------ 1 stephane stephane 64 mars 16 20:15 3 -> /dev/ptmx lrwx------ 1 stephane stephane 64 mars 16 20:15 4 -> /dev/pts/21 lrwx------ 1 stephane stephane 64 mars 16 20:15 5 -> anon_inode:[signalfd] l-wx------ 1 stephane stephane 64 mars 16 20:15 6 -> /somewhere/mylogfile.txt l-wx------ 1 stephane stephane 64 mars 16 20:15 7 -> /somewhere/mylogfile_timings.txt What can we do? ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: bsdutils 1:2.27.1-6ubuntu1 ProcVersionSignature: Ubuntu 4.4.0-13.29-generic 4.4.5 Uname: Linux 4.4.0-13-generic x86_64 ApportVersion: 2.20-0ubuntu3 Architecture: amd64 CurrentDesktop: XFCE Date: Wed Mar 16 20:04:02 2016 ExecutablePath: /usr/bin/script InstallationDate: Installed on 2016-02-03 (41 days ago) InstallationMedia: Xubuntu 16.04 LTS "Xenial Xerus" - Alpha amd64 (20160203) SourcePackage: util-linux UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1558236/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
