Date: Mon, 12 Jan 2009 11:45:03 -0800 (PST)
From: Linus Torvalds <torvalds@linux-foundation.org>
To: "H. Peter Anvin" <hpa@zytor.com>
cc: Andi Kleen <andi@firstfloor.org>, Bernd Schmidt <bernds_cb1@t-online.de>,
       David Woodhouse <dwmw2@infradead.org>,
       Andrew Morton <akpm@linux-foundation.org>, Ingo Molnar <mingo@elte.hu>,
       Harvey Harrison <harvey.harrison@gmail.com>,
       Chris Mason <chris.mason@oracle.com>,
       Peter Zijlstra <peterz@infradead.org>,
       Steven Rostedt <rostedt@goodmis.org>, paulmck@linux.vnet.ibm.com,
       Gregory Haskins <ghaskins@novell.com>, Matthew Wilcox <matthew@wil.cx>,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
       linux-fsdevel <linux-fsdevel@vger.kernel.org>,
       linux-btrfs <linux-btrfs@vger.kernel.org>,
       Thomas Gleixner <tglx@linutronix.de>, Nick Piggin <npiggin@suse.de>,
       Peter Morreale <pmorreale@novell.com>,
       Sven Dietrich <SDietrich@novell.com>, jh@suse.cz
Subject: Re: gcc inlining heuristics was Re: [PATCH -v7][RFC]: mutex: implement
 adaptive spinning
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On Mon, 12 Jan 2009, H. Peter Anvin wrote:
> 
> This is about storage allocation, not aliases.  Storage allocation only
> depends on lifetime.

Well, the thing is, code motion does extend life-times, and if you think 
you can move stores across each other (even when you can see that they 
alias statically) due to type-based alias decisions, that does essentially 
end up making what _used_ to be disjoint lifetimes now be potentially 
overlapping.

			Linus
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