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Date: Mon, 04 Jul 2005 20:06:33 +1000
From: Peter Grehan <grehan@freebsd.org>
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To: Robert Watson <rwatson@freebsd.org>
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Cc: cvs-src@freebsd.org, src-committers@freebsd.org, cvs-all@freebsd.org,
	Andrew Thompson <thompsa@freebsd.org>
Subject: Re: cvs commit: src/sys/amd64/include _types.h src/sys/i386/include
 _types.h src/sys/net if_bridge.c src/sys/netinet ip_var.h       
 src/sys/netinet6 ip6_var.h
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>> FYI, any modern ppc implementation doesn't require strict alignment 
>> for integer load/stores though there's a performance penalty for 
>> having to split the access into smaller ones. 
> 
> While it's not immediately relevant to the IP code, generally speaking, 
> is it the case that non-aligned integer reads can be non-atomic with 
> respect to other CPUs due to the multiple access implementation?

  I'd say certainly ! In fact, are there any architectures that could 
guarantee atomicity in this case ?

later,

Peter.