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Date: Tue, 06 Nov 2007 21:05:00 +0100
From: Fabrice Bellard <fabrice@bellard.org>
Subject: Re: [Qemu-devel] RFC: x86_64 Best way to fix 'cast to pointer from
	integer of different size' problems?
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To: qemu-devel@nongnu.org

Paul Brook wrote:
> [...]
> Personally I like the locking interface as it allows a zero-copy 
> implementation. However the kernel uses a copying interface, and my 
> understanding is that other qemu maintainers also prefer the copying 
> interface.

At least I don't think it is critical performance wise, especially if
the page flag checks are added ! Before you added the current zero copy
interface, my plan was to use a zero copy interface just for big buffers
such as the one for read/write.

Another point is that the code from signal.c is not converted to the
zero-copy interface and it is a significant source of complexity as
there is a large amount of target specific code copied from the Linux
kernel to generate the stack frame.

Regards,

Fabrice.