From owner-freebsd-arch@FreeBSD.ORG  Sun Jan 21 22:21:44 2007
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Date: Sun, 21 Jan 2007 14:21:41 -0800
From: Luigi Rizzo <rizzo@icir.org>
To: Poul-Henning Kamp <phk@phk.freebsd.dk>
Message-ID: <20070121142141.A83926@xorpc.icir.org>
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	from phk@phk.freebsd.dk on Sun, Jan 21, 2007 at 10:10:23PM +0000
Cc: Ivan Voras <ivoras@fer.hr>, freebsd-arch@freebsd.org
Subject: Re: bzero & bcopy alignment
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On Sun, Jan 21, 2007 at 10:10:23PM +0000, Poul-Henning Kamp wrote:
> In message <20070121140019.A83688@xorpc.icir.org>, Luigi Rizzo writes:
> >On Sun, Jan 21, 2007 at 10:41:09PM +0100, Ivan Voras wrote:
> >> Following recent discussion on alignment of bzero() and bcopy(), I've
> >> added some statistics collecting code to bzero() and bcopy() for
> >> practice (on a RELENG_6 box), and here are the cumulative results for
> >> argument alignment:
> >
> >i think these profiles depend heavily on the hardware
> >and usage patterns.
> 
> Undoubtedly, but on the other hand, a lot of them operate on
> structs and other data laid out by the compiler, so the
> unaligned calls are special cases.

and that is why i suggested to instrument the functions to record
where in the source the unaligned functions are called, so we can
figure out whether it is something unavoidable or something
that can be fixed.

	cheers
	luigi