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Date: Thu, 26 Aug 2010 10:55:13 +0530
From: Amit Shah <amit.shah@redhat.com>
Subject: Re: [Qemu-devel] [PATCH V2] balloon: Don't try fetching info if
	machine is stopped
Message-ID: <20100826052513.GE18351@amit-laptop.redhat.com>
References: <8450ea8e785c9049f0b3edddc01650a8c4b9ffe7.1282265244.git.amit.shah@redhat.com>
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To: Anthony Liguori <anthony@codemonkey.ws>
Cc: Paolo Bonzini <pbonzini@redhat.com>, agl@us.ibm.com, qemu list <qemu-devel@nongnu.org>, Juan Quintela <quintela@redhat.com>

On (Sun) Aug 22 2010 [16:54:06], Anthony Liguori wrote:
> On 08/19/2010 07:48 PM, Amit Shah wrote:
> >If the machine is stopped and 'info balloon' is invoked, the monitor
> >process just hangs waiting for info from the guest. Return the most
> >recent balloon data in that case.
> >
> >See https://bugzilla.redhat.com/show_bug.cgi?id=623903
> >
> >Reported-by:<lihuang@redhat.com>
> >Signed-off-by: Amit Shah<amit.shah@redhat.com>
> 
> !vm_running is just a special case of an unresponsive guest.  Even
> if the guest was running, if it was oops'd and the administrator
> didn't know, you would have the same issue.

True.

> I'd suggest using a timeout based on rt_clock.  If the stats request
> times out, print an appropriate message to the user.

What should the timeout be?

A heavily-loaded guest could reply later which would cause problems --
I don't think we handle async input from the guest today.

		Amit