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From: Stephan Mueller <smueller@chronox.de>
To: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Will Deacon <will.deacon@arm.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	"Theodore Ts'o" <tytso@mit.edu>,
	Hannes Frederic Sowa <hannes@stressinduktion.org>,
	mancha security <mancha1@zoho.com>,
	Mark Charlebois <charlebm@gmail.com>,
	Behan Webster <behanw@converseincode.com>,
	Herbert Xu <herbert@gondor.apana.org.au>
Subject: Re: interesting commit about llvm introducing barrier_data()
Date: Tue, 23 Feb 2016 15:46:19 +0100	[thread overview]
Message-ID: <1605703.GSn7kbzMda@tauon.atsec.com> (raw)
In-Reply-To: <675593567.5328.1456237963352.JavaMail.zimbra@efficios.com>

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Am Dienstag, 23. Februar 2016, 14:32:43 schrieb Mathieu Desnoyers:

Hi Mathieu,

> ----- On Feb 23, 2016, at 9:23 AM, Paul E. McKenney 
paulmck@linux.vnet.ibm.com wrote:
> > On Tue, Feb 23, 2016 at 02:02:26PM +0000, Mathieu Desnoyers wrote:
> >> commit 7829fb09a2b4268b30dd9bc782fa5ebee278b137
> >> Author: Daniel Borkmann <daniel@iogearbox.net>
> >> Date:   Thu Apr 30 04:13:52 2015 +0200
> >> 
> >>     lib: make memzero_explicit more robust against dead store elimination
> >> 
> >> ^ interesting commit. Any idea on the impact of this on kernel RCU
> >> implementation and liburcu cmm_barrier() ?
> > 
> > First I knew of it!  But I bet that more like this are needed.  ;-)
> 
> I recommend you check my IRC discussion with peterz on the matter of
> this new "barrier_data()".
> 
The key idea of the memzero_explicit is about forcing the compiler to do a 
memset.

See the trivial test attached.

Ciao
Stephan

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  reply	other threads:[~2016-02-23 14:46 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <1168693945.5302.1456236146207.JavaMail.zimbra@efficios.com>
     [not found] ` <20160223142336.GK3522@linux.vnet.ibm.com>
2016-02-23 14:32   ` interesting commit about llvm introducing barrier_data() Mathieu Desnoyers
2016-02-23 14:46     ` Stephan Mueller [this message]
2016-02-23 14:58       ` Mathieu Desnoyers
2016-02-23 16:10         ` Paul E. McKenney

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