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From: Jon Masters <jonathan@jonmasters.org>
To: paulmck@linux.vnet.ibm.com
Cc: tony.luck@intel.com, peterz@infradead.org, linux-kernel@vger.kernel.org
Subject: Re: Does Itanium permit speculative stores?
Date: Tue, 26 Nov 2013 23:55:58 -0500	[thread overview]
Message-ID: <52957B5E.60701@jonmasters.org> (raw)
In-Reply-To: <20131111171307.GA27002@linux.vnet.ibm.com>

On 11/11/2013 12:13 PM, Paul E. McKenney wrote:
> Hello, Tony,
> 
> Does Itanium permit speculative stores?  For example, on Itanium what are
> the permitted outcomes of the following litmus test, where both x and y
> are initially zero?
> 
> 	CPU 0				CPU 1
> 
> 	r1 = ACCESS_ONCE(x);		r2 = ACCESS_ONCE(y);
> 	if (r1)				if (r2)
> 		ACCESS_ONCE(y) = 1;		ACCESS_ONCE(x) = 1;
> 
> In particular, is the outcome (r1 == 1 && r2 == 1) possible on Itanium
> given this litmus test?
> 
> 							Thanx, Paul
> 
> --
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> 

Btw, I was reading through some UEFI docs and noticed a reference to "A
Formal Specification of Intel Itanium Processor Family Memory Ordering",
then remembered this thread. In case it's of use:

http://www.intel.com/design/itanium/downloads/251429.htm

Jon.


  parent reply	other threads:[~2013-11-27  5:24 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-11-11 17:13 Does Itanium permit speculative stores? Paul E. McKenney
2013-11-12 18:00 ` Luck, Tony
2013-11-12 18:26   ` Peter Zijlstra
2013-11-12 18:46     ` Luck, Tony
2013-11-12 18:49       ` Peter Zijlstra
2013-11-12 21:29       ` Paul E. McKenney
2013-11-12 21:30     ` Paul E. McKenney
2013-11-12 18:31   ` Paul E. McKenney
2013-11-12 18:34   ` Peter Zijlstra
2013-11-27  4:55 ` Jon Masters [this message]
2013-11-27 17:19   ` Paul E. McKenney

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