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Re: Unacceptable behavior -- slowing down script execution


SJ Wright wrote:
Hi folks.

Through fits and starts, and with no more feedback from the list than Dave Korn's self-admitted "wild guess" about gcclib1 folders etc, my Cygwin is no longer shedding empty shell stack-dump files like dandruff. But certain things are continuing to alarm me. I'll put them in the form of questions and whoever knows the answers, please take the time to do so.

1. Is it normal behavior, once rxvt is launched, for cmd.exe to remain running as a process?
2. Using a batch-to-executable utility, I converted a customized rxvt-launching .bat file into an executable. Should this also stay open as a process in Task Manager once its work is done?
3. Is it normal behavior for one BASH script to spawn more than one subshell?
4. Is it normal for any script to run CPU usage up to 100%?


Regarding #4:
I have a script that I ran in GNOME Terminal less than an hour ago. I "time"d it -- the return was 20.6 seconds on the first line (real?). I ran the same script fifteen minutes later, evaluating identical files of the same type, length (5.37kb and 345b ASCII text) and time stamp, and after 7 minutes it was barely one-eighth complete. That's when I checked Task Manager and found my CPU usage was at 100% and three bash.exe's were running simultaneously. Admittedly the script calls on several externals, but considering the difference in completion times -- I estimate that had I not interrupted the process with ctrl-c, the Cygwin run would have taken just under 40 minutes to finish -- _and the fact that it spawned an unusual number of subshells, it doesn't speak highly for Cygwin as a viable option or means for people to "keep their hand in" w/re their Unix skill-sets.


5. Is this a bug peculiar to this version/build of Cygwin? I don't recall any such issues when running complicated scripts before 1.7.x.

Hoping someone can answer any or all of the foregoing.

Cheers, SJ Wright



The above message:http://www.cygwin.com/ml/cygwin/2010-09/msg00568.html
I have found other messages that discuss the 100% CPU load issue in previous versions of Cygwin. No wonder no one's bothered to answer my questions yet -- evidently one should take it as read that anything fancier than cmd.exe as a terminal emulator will do this.


Okay, so here's QUESTION #6:
Why should a bash script call up sh.exe, not once but as many as three times, as processes in Task Manager when run in the current version of Cygwin?


As for the slowdown in script execution: I've pondered using ssh, scp and ftp to do all my heavier-load script running remotely to my Linux laptop. QUESTION #7: Am I the only one who thinks this shouldn't be necessary?

Here's hoping I've piqued someone's interest.

Cheers again, SJ Wright


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