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From: Fabrice Bellard <fabrice@bellard.org>
To: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] RFC: x86_64 Best way to fix 'cast to pointer from integer of different size' problems?
Date: Tue, 06 Nov 2007 21:05:00 +0100	[thread overview]
Message-ID: <4730C8EC.8030808@bellard.org> (raw)
In-Reply-To: <200711060105.04529.paul@codesourcery.com>

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.

  parent reply	other threads:[~2007-11-06 20:05 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-11-03 17:26 [Qemu-devel] RFC: x86_64 Best way to fix 'cast to pointer from integer of different size' problems? TJ
2007-11-03 17:52 ` Paul Brook
2007-11-05 19:51   ` Thayne Harbaugh
2007-11-06  1:05     ` Paul Brook
2007-11-06  2:00       ` Thayne Harbaugh
2007-11-07 19:18         ` Fabrice Bellard
2007-11-07 20:59           ` Thayne Harbaugh
2007-11-07 23:02           ` Paul Brook
2007-11-12 16:42           ` Thayne Harbaugh
2007-11-06 20:05       ` Fabrice Bellard [this message]
2007-11-06 21:52         ` Stuart Anderson
2007-11-06 22:05           ` Paul Brook
2007-11-06 22:19             ` Stuart Anderson

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