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From: Paul Brook <paul@codesourcery.com>
Subject: Re: [Qemu-devel] Re: [PATCH] Add cache=volatile parameter to -drive
Date: Mon, 17 May 2010 17:23:15 +0100
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To: qemu-devel@nongnu.org
Cc: kwolf@redhat.com, Alexander Graf <agraf@suse.de>, hch@lst.de

> > I don't see a difference between the results. Apparently the barrier
> > option doesn't change a thing.
> 
> Ok.  I don't like it, but I can see how it's compelling.  I'd like to
> see the documentation improved though.  I also think a warning printed
> on stdio about the safety of the option would be appropriate.

I disagree with this last bit.

Errors should be issued if the user did something wrong.
Warnings should be issued if qemu did (or will soon do) something other than 
what the user requested, or otherwise made questionable decisions on the 
user's behalf.

In this case we're doing exactly what the user requested. The only plausible 
failure case is where a user is blindly trying options that they clearly don't 
understand or read the documentation for. I have zero sympathy for complaints 
like "Someone on the Internet told me to use --breakme, and broke thinks".

Paul