This is the mail archive of the
mailing list for the Cygwin project.
Re: Hope this topic isn't taboo yet
- From: "Brett Serkez" <techie at serkez dot net>
- To: cygwin at cygwin dot com
- Date: Sun, 01 Jan 2006 15:01:11 -0500
- Subject: Re: Hope this topic isn't taboo yet
I've not seen any particular difference using Cygwin between
hyper-threaded and non-hyper-threaded CPUs. I have seen issues with
bash and sshd consuming 100% CPU for periods of time on both, which may
or may not be related to ZoneAlarm.
You can better identify the specific process by starting the task
manager, and looking at the 'Processes' tab. I usually add the 'CPU
Time' column via 'View -> Select Columns', so I can sort on it and see
which processes are consuming allot of CPU over time and sort on the CPU
column when looking while the problem is occuring to see which process
is consuming allot of CPU in real-time.
On the ZoneLabs message boards I found references to use of tcsh in
place of bash, that seems to work around the problem as follows:
- Run setup and select tcsh from shells
- Modify /etc/passwd and change /bin/bash to /bin/tcsh for all
- Modify c:\cygwin\cygwin.bat and change 'bash --login' to 'tcsh -l'
- Modify individual scripts, as appropriate, and change the she-bang
line to: #!/bin/tcsh.
This is an imperfect solution, but I've seen a noticable performance
improvement as well as elimination of the CPU spikes.
If you also run the secure shell daemon (sshd), before running
ssh-host-config, modify it by locating '-a -D' and change to '-a "-D
-r"' in two places. Adding the -r, which is applied to the -a which is
why the double quotes are needed, turns off an extra fork/exec that
theoretically makes sshd more secure but also causes the CPU spike. If
you've already installed sshd as a service, you'll need to stop it and
delete it before making these changes.
It is my intuition that both issues revolve around process creation and
security software examination of these events, looking for viruses and
Brett C. Serkez, Techie
Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
Problem reports: http://cygwin.com/problems.html