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Re: [Xen-devel] "xm save" trouble -- deadlock?

To: Gerd Knorr <kraxel@xxxxxxx>
Subject: Re: [Xen-devel] "xm save" trouble -- deadlock?
From: Ewan Mellor <ewan@xxxxxxxxxxxxx>
Date: Wed, 2 Nov 2005 10:04:29 +0000
Cc: xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxx>
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On Wed, Nov 02, 2005 at 10:25:36AM +0100, Gerd Knorr wrote:

>   Hi,
> 
> >The code that does this is in XendCheckpoint.py:forkHelper.  It's using
> >select.poll() and file.readline() to read from both the stdout and the
> >stderr.  This is a pretty daft thing to do -- there's definitely potential 
> >for
> >deadlock here.
> >
> >I'll rewrite this to use a separate thread to pull the data from stderr, 
> >which
> >should solve the problem.
> 
> Should be fixable without a new thread, I'll have a look. 

I've done a threaded fix already.  You're welcome to have a go at doing it
without a thread if you want, but I think it'll be messy.

> log.debug("stuff") ends up in /var/log/xend.log I guess?

Yes, it does.

I've assigned this bug #378.

Ewan.

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