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From: Bernd Petrovitsch <bernd@petrovitsch.priv.at>
To: "Boehm, Hans" <hans.boehm@hp.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Torvald Riegel <triegel@redhat.com>, Jan Kara <jack@suse.cz>,
	LKML <linux-kernel@vger.kernel.org>,
	"linux-ia64@vger.kernel.org" <linux-ia64@vger.kernel.org>,
	"dsterba@suse.cz" <dsterba@suse.cz>,
	"ptesarik@suse.cz" <ptesarik@suse.cz>,
	"rguenther@suse.de" <rguenther@suse.de>,
	"gcc@gcc.gnu.org" <gcc@gcc.gnu.org>
Subject: RE: Memory corruption due to word sharing
Date: Thu, 02 Feb 2012 10:28:42 +0100	[thread overview]
Message-ID: <1328174924.12177.17.camel@thorin> (raw)
In-Reply-To: <A3E67C2071F49C4CBC4F17E6D77CDDD232754151@G4W3299.americas.hpqcorp.net>

On Mit, 2012-02-01 at 21:04 +0000, Boehm, Hans wrote:
[...]
> The C11 memory model potentially adds overhead in only two cases:
> 
> 1. When current code involves touching a field that wouldn't otherwise
> be touched.  There are odd cases in which this measurably slows down
> code, but I think all agree that we need it.  In addition to
> bitfields, it can affect speculatively promoting a value to a register
> in a loop, which at least older versions of gcc also do.

Just adding an -f option for this and/or activating it only for -O5 (or
whatever the highest level is) and - in case that feature is activated -
emit warnings if bitfields (and/or any other data types that might be
affected)?

Kind regards,
	Bernd
-- 
Bernd Petrovitsch                  Email : bernd@petrovitsch.priv.at
                     LUGA : http://www.luga.at


  reply	other threads:[~2012-02-02  9:29 UTC|newest]

Thread overview: 67+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-02-01 15:19 Memory corruption due to word sharing Jan Kara
2012-02-01 15:34 ` Markus Trippelsdorf
2012-02-01 16:37 ` Colin Walters
2012-02-01 16:56   ` Linus Torvalds
2012-02-01 17:11     ` Jiri Kosina
2012-02-01 17:37       ` Linus Torvalds
2012-02-01 17:41       ` Michael Matz
2012-02-01 18:09         ` David Miller
2012-02-01 18:45           ` Jeff Law
2012-02-01 19:09             ` Linus Torvalds
2012-02-02 15:51               ` Jeff Garzik
2012-02-01 18:57           ` Linus Torvalds
2012-02-01 19:04           ` Peter Bergner
2012-02-01 18:52         ` Linus Torvalds
2012-02-02  9:35           ` Richard Guenther
2012-02-02  9:37           ` Richard Guenther
2012-02-02 13:43           ` Michael Matz
2012-02-01 16:41 ` Linus Torvalds
2012-02-01 17:42   ` Torvald Riegel
2012-02-01 19:40     ` Jakub Jelinek
2012-02-01 20:01       ` Linus Torvalds
2012-02-01 20:16         ` Jakub Jelinek
2012-02-01 20:44           ` Linus Torvalds
2012-02-02 15:58             ` Aldy Hernandez
2012-02-02 16:28               ` Michael Matz
2012-02-02 17:51                 ` Linus Torvalds
2012-02-01 20:19         ` Linus Torvalds
2012-02-02  9:46           ` Richard Guenther
2012-02-01 19:44     ` Boehm, Hans
2012-02-01 19:54       ` Jeff Law
2012-02-01 19:47     ` Linus Torvalds
2012-02-01 19:58       ` Alan Cox
2012-02-01 20:41       ` Torvald Riegel
2012-02-01 20:59         ` Linus Torvalds
2012-02-01 21:24           ` Torvald Riegel
2012-02-01 21:55             ` Linus Torvalds
2012-02-01 21:25           ` Boehm, Hans
2012-02-01 22:27             ` Linus Torvalds
2012-02-01 22:45           ` Paul E. McKenney
2012-02-01 23:11             ` Linus Torvalds
2012-02-02 18:42               ` Paul E. McKenney
2012-02-02 19:08                 ` Linus Torvalds
2012-02-02 19:37                   ` Paul E. McKenney
2012-02-03 16:38                     ` Andrew MacLeod
2012-02-03 17:16                       ` Linus Torvalds
2012-02-03 19:16                         ` Andrew MacLeod
2012-02-03 20:00                           ` Linus Torvalds
2012-02-03 20:19                             ` Paul E. McKenney
2012-02-06 15:38                             ` Torvald Riegel
2012-02-10 19:27                             ` Richard Henderson
2012-02-02 11:19           ` Ingo Molnar
2012-02-01 21:04       ` Boehm, Hans
2012-02-02  9:28         ` Bernd Petrovitsch [this message]
2012-02-01 17:08 ` Torvald Riegel
2012-02-01 17:29   ` Linus Torvalds
2012-02-01 20:53     ` Torvald Riegel
2012-02-01 21:20       ` Linus Torvalds
2012-02-01 21:37         ` Torvald Riegel
2012-02-01 22:18           ` Boehm, Hans
2012-02-02 11:11 ` James Courtier-Dutton
2012-02-02 11:24   ` Richard Guenther
2012-02-02 11:13 ` David Sterba
2012-02-02 11:23   ` Richard Guenther
2012-02-03  6:45 ` DJ Delorie
2012-02-03  9:37   ` Richard Guenther
2012-02-03 10:03     ` Matthew Gretton-Dann
  -- strict thread matches above, loose matches on Subject: below --
2012-02-01 17:52 Dennis Clarke

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