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From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>,
	Davidlohr Bueso <dave@stgolabs.net>,
	Dmitry Vyukov <dvyukov@google.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Ingo Molnar <mingo@kernel.org>
Subject: Re: [PATCH RFC] locking: Add volatile to arch_spinlock_t structures
Date: Thu, 4 Dec 2014 12:12:05 -0800	[thread overview]
Message-ID: <20141204201205.GA27787@linux.vnet.ibm.com> (raw)
In-Reply-To: <20141204200052.GY25340@linux.vnet.ibm.com>

On Thu, Dec 04, 2014 at 12:00:52PM -0800, Paul E. McKenney wrote:

[ . . . ]

> So any compiler that clobbers some adjacent non-bitfield variable or
> field that is accessible by other threads is not just despicable, it
> fails to conform to the standard.
> 
> Whew!  ;-)

And part of the reason for my confusion is that I am using an old version
of gcc, 4.6.3.  Apparently this aspect of gcc wasn't fixed until 4.7
or thereabouts.

							Thanx, Paul


  reply	other threads:[~2014-12-04 20:12 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-12-04  6:20 [PATCH RFC] locking: Add volatile to arch_spinlock_t structures Paul E. McKenney
     [not found] ` <CA+55aFzn-6asfWHB8SAvz4GJWz7uEriujgVLfaqoo_VPtNBLuA@mail.gmail.com>
2014-12-04  6:57   ` Paul E. McKenney
     [not found]   ` <CA+55aFxGCxQNE4HzRP_Uk2FmFDn_+Hfm6GBz75S+5+SDeODVJQ@mail.gmail.com>
2014-12-04  7:02     ` Paul E. McKenney
2014-12-04 18:02       ` Linus Torvalds
2014-12-04 18:36         ` Paul E. McKenney
2014-12-04 19:18           ` Linus Torvalds
2014-12-04 20:00             ` Paul E. McKenney
2014-12-04 20:12               ` Paul E. McKenney [this message]
2014-12-04 21:45           ` One Thousand Gnomes
2014-12-04 22:06             ` Paul E. McKenney

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