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From: David Miller <davem@davemloft.net>
To: npiggin@suse.de
Cc: paulmck@linux.vnet.ibm.com, torvalds@linux-foundation.org,
	anton@samba.org, akpm@linux-foundation.org,
	willy@linux.intel.com, benh@kernel.crashing.org,
	paulus@samba.org, linux-arch@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2]: atomic_t: Remove volatile from atomic_t definition
Date: Thu, 20 May 2010 23:10:37 -0700 (PDT)	[thread overview]
Message-ID: <20100520.231037.200798708.davem@davemloft.net> (raw)
In-Reply-To: <20100521060600.GM2516@laptop>

From: Nick Piggin <npiggin@suse.de>
Date: Fri, 21 May 2010 16:06:00 +1000

> Actually, I bet we have a lot of bugs there with loading integers and
> pointers atomically, where the code assumes the loaded value will not
> be reloaded by the compiler, because it is an easy thing to assume.

Alexey Kuznetsov was aware of this problem 8+ years ago when we were
first adding fine-grained locking the the networking.

> atomic_read_light could be useful though, for sure.

I definitely think so. And every usage of it should have a big fat
comment right next to it explaining how it's usage is valid in that
spot :-)

  reply	other threads:[~2010-05-21  6:10 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-05-17  4:33 [PATCH 1/2]: atomic_t: Cast to volatile when accessing atomic variables Anton Blanchard
2010-05-17  4:34 ` [PATCH 2/2]: atomic_t: Remove volatile from atomic_t definition Anton Blanchard
2010-05-17  8:58   ` Heiko Carstens
2010-05-17 15:01   ` Linus Torvalds
2010-05-17 20:13     ` Jamie Lokier
2010-05-17 20:20       ` Linus Torvalds
2010-05-19 13:03     ` Nick Piggin
2010-05-19 14:55       ` Linus Torvalds
2010-05-19 15:01       ` Paul E. McKenney
2010-05-19 19:54         ` David Miller
2010-05-19 22:50           ` Paul E. McKenney
2010-05-21  5:27             ` Nick Piggin
2010-05-21  5:54               ` David Miller
2010-05-21  6:06                 ` Nick Piggin
2010-05-21  6:10                   ` David Miller [this message]
2010-05-21  6:44                     ` Eric Dumazet

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