st: Strange behaviour of Stata 11 under GNU/Linux

[Neil Shephard <nshephard@gmail.com>]

I was wondering if anyone else can replicate the following (strange)
behaviour of Stata 11.1 under GNU/Linux (or any other OS).

Hitting 'Ctrl + w' causes Stata to hang, using ~97-100% of one CPU and
has to be killed.

System Info
===========

. about

Stata/IC 11.1 for Unix (Linux 64-bit x86-64)
Born 16 Jun 2010
Copyright (C) 2009 StataCorp LP

Single-user Stata perpetual license:
       Serial number:  *******************
         Licensed to:  Neil Shephard
                       ScHARR, University of Sheffield

Kernel version...

$ uname -a
Linux morgan 2.6.34-gentoo-r2 #4 SMP Thu Jul 29 13:25:22 GMT 2010
x86_64 Intel(R) Core(TM)2 Duo CPU E8500 @ 3.16GHz GenuineIntel
GNU/Linux

GTK version...

$ eix -I gtk+
[I] x11-libs/gtk+
     Available versions:
	(1)	1.2.10-r12
	(2)	2.16.6 2.18.6 2.18.7 2.18.9 (~)2.20.1-r1
	{aqua cups debug doc +introspection jpeg jpeg2k linguas_az linguas_ca
linguas_cs linguas_da linguas_de linguas_el linguas_es linguas_et
linguas_eu linguas_fi linguas_fr linguas_ga linguas_gl linguas_hr
linguas_hu linguas_it linguas_ja linguas_ko linguas_lt linguas_nl
linguas_nn linguas_no linguas_pl linguas_pt linguas_pt_BR linguas_ro
linguas_ru linguas_sk linguas_sl linguas_sr linguas_sv linguas_tr
linguas_uk linguas_vi nls test tiff vim-syntax xinerama}
     Installed versions:  2.20.1-r1(2)(09:45:44 15/07/10)(cups jpeg
tiff -aqua -debug -doc -introspection -jpeg2k -test -vim-syntax
-xinerama)
     Homepage:            http://www.gtk.org/
     Description:         Gimp ToolKit +



Background
=========

'Ctrl + w' at a command prompt deletes back to the previous space in
the current command line.  I accidentally hit this whilst focused on
Stata as opposed to a terminal and immediately Stata 'hung' and the
CPU graph in the task bar went to 50% (NB Its a dual core system hence
the graph showed 50% usage as this is IC Stata as opposed to MP, a
check of -top- showed xstata to be using all the resources, see
below).

top - 09:52:11 up 20:06,  4 users,  load average: 0.43, 0.27, 0.17
Tasks: 144 total,   2 running, 141 sleeping,   0 stopped,   1 zombie
Cpu(s): 52.6%us,  1.0%sy,  0.0%ni, 46.4%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Mem:   2011168k total,  1623936k used,   387232k free,    46724k buffers
Swap:        0k total,        0k used,        0k free,   723056k cached


  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
14677 neil      20   0  284m  41m 6244 R   99  2.1   0:34.58 xstata
 2947 neil      20   0  175m  34m 6040 S    3  1.8  44:09.99 npviewer.bin
 2341 root      20   0  137m  28m 6976 S    1  1.4  68:19.84 X
 2401 mpd       20   0  218m 8560 2860 S    1  0.4   0:42.73 mpd
 2657 neil      20   0 1060m 442m  23m S    1 22.5  41:12.42 firefox
 2665 neil      20   0  130m 6804 5276 S    1  0.3   2:21.19 xfce4-cpugraph-
 2681 neil      20   0  316m  14m 8784 S    1  0.7   0:02.99 Terminal

Strange behaviour I thought, so before posting thought I'd see if it
was an artefact of the data that I had loaded/process I'd run by
starting a fresh session of xstata.  After a fresh start 'Ctrl + w'
had no effect, however, if I 'cd ~/tmp' and _then_ 'Ctrl + w' the
behaviour described above is replicated and Stata hangs.  No data was
loaded, nor any other commands used other than -cd- to change the
current working directory.

In typing this I have switched desktops and focus has moved away from
the Stata window, and after a few minutes the CPU usage drops back to
zero, but Stata is still hanging and no typing can be done.  If I
return to the desktop with Stata on and focus back on the window, CPU
usage goes back up to 97-100% maxing out one of the processors.

I thought I'd check to see if any more information could be obtained
when launching xstata from a terminal, but there was none.  The
behaviour is not observed in the CLI version either.

All very strange,

Neil

-- 
"... no scientific worker has a fixed level of significance at which
from year to year, and in all circumstances, he rejects hypotheses; he
rather gives his mind to each particular case in the light of his
evidence and his ideas." - Sir Ronald A. Fisher (1956)

Email - nshephard@gmail.com
Website - http://slack.ser.man.ac.uk/
Photos - http://www.flickr.com/photos/slackline/
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