Re: Cygwin processes getting stuck on max CPU usage; XP SP2 problem?

[Igor Pechtchanski <pechtcha at cs dot nyu dot edu>]

On Thu, 23 Sep 2004, Simon Barnes wrote:

> > If you have symbols installed and you list the threads for the hung
> > Cygwin process you'll see the stuck one is in a loop in
> > ntdll.dll!RtlConvertUiListToApiList, as well as a corresponding thread
> > in csrss.exe (CSRSRV.dll!ValidateMessageString) for each.  The CPU usage
> > seems to be split equally between them all.
> >
> > So, it's definitely an interaction between Cygwin and Process Explorer's
> > grubby little fingers... however no one seems to be interestd in fixing
> > it so for the time being the solution seems to be "Don't accidently
> > enable the 'DLLs View' of a cygwin process in ProcExp."
>
> Some of my colleagues and I are seeing this without using Process
> Explorer.  No doubt some other automated process is triggering it, but we
> don't know which.
>
> Is there anything I can do to help work towards a fix?  It's moderately
> inconvenient having to restart rxvt or bash every few hours.

Well, since you asked...

Trying to isolate this to a simple testcase would be a start.  Create a
simple program that depends only on a debug build of cygwin1.dll (to avoid
conflicts with the running Cygwin processes), then start cutting out
modules from the debug cygwin1.dll until it's down to a few functions and
initialization routines that still reproduce the problem.  If you can get
it down to one function -- all the better.  Then read MSDN on the
interaction between whatever you have in your testcase and
RtlConvertUiListToApiList.  Hopefully come up with a fix and post a patch,
but if not, posting your testcase (if you can get it down to 200 lines or
less) would be of help too.

At the very least the above assumes the ability to set up a build and
debug environment for Cygwin's internals, but I hope this helps someone
start working on this problem.
	Igor
-- 
				http://cs.nyu.edu/~pechtcha/
      |\      _,,,---,,_		pechtcha@cs.nyu.edu
ZZZzz /,`.-'`'    -.  ;-;;,_		igor@watson.ibm.com
     |,4-  ) )-,_. ,\ (  `'-'		Igor Pechtchanski, Ph.D.
    '---''(_/--'  `-'\_) fL	a.k.a JaguaR-R-R-r-r-r-.-.-.  Meow!

"Happiness lies in being privileged to work hard for long hours in doing
whatever you think is worth doing."  -- Dr. Jubal Harshaw

--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/