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Diffstat (limited to 'open_issues/bash_busy-loop.mdwn')
| -rw-r--r-- | open_issues/bash_busy-loop.mdwn | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/open_issues/bash_busy-loop.mdwn b/open_issues/bash_busy-loop.mdwn new file mode 100644 index 00000000..5228ba33 --- /dev/null +++ b/open_issues/bash_busy-loop.mdwn @@ -0,0 +1,33 @@ +[[!meta copyright="Copyright © 2010 Free Software Foundation, Inc."]] + +[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable +id="license" text="Permission is granted to copy, distribute and/or modify this +document under the terms of the GNU Free Documentation License, Version 1.2 or +any later version published by the Free Software Foundation; with no Invariant +Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license +is included in the section entitled [[GNU Free Documentation +License|/fdl]]."]]"""]] + +I've first seen this problem after having had the following command line run +for a week, or two, or three: + +Start `screen`. Find PID of pfinet. + + $ while sleep 66; do echo "$(date)" " $(ps --no-header --format=hurd -p [PID])"; done | tee ps-pfinet + +Leave it running, detach from `screen`. + +Eventually, the main `bash` process will go bonkers and eat 100 % CPU time. +Reproduced on four different systems. + +A faster way to reproduce this, again inside `screen`; every three seconds, +write text in 10 MiB bursts to the terminal: + + $ while sleep 3; do date > tmp/tmp && yes "$(date)" | dd bs=1M count=10; done + +This one only needs like ten hours, before `bash` starts its busy-loop, from +which it can only be terminated with `SIGKILL`. At this point, the `term`, +`screen`, `fifo` processes also have used 40, 52, 25 minutes of CPU time, +respectively, but appear to be still working fine. + +I did not yet start debugging this. |