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To: Peter Grehan <grehan@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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On Mon, 4 Jul 2005, Peter Grehan wrote:

>>   Check the alignment of the IP header before passing the packet up to the
>>   packet filter. This would cause a panic on architectures that require 
>> strict
>>   alignment such as sparc64 (tier1) and ia64/ppc (tier2).
>
> 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?

Robert N M Watson