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Subject: Re: [PATCH 1/2] lib: Provide generic atomic64_t implementation
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Mike Frysinger <vapier.adi@gmail.com>
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Date: Fri, 19 Jun 2009 10:46:14 +1000
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Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org,
	Paul Mackerras <paulus@samba.org>, linux-kernel@vger.kernel.org,
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On Thu, 2009-06-18 at 19:55 -0400, Mike Frysinger wrote:
> On Sat, Jun 13, 2009 at 03:10, Paul Mackerras wrote:
> > +typedef struct {
> > +       long long counter;
> > +} atomic64_t;
> 
> lack of volatile seems odd compared to:
> include/linux/types.h:
> typedef struct {
>     volatile int counter;
> } atomic_t;

Since the counter is only accessed within a spinlock, the volatile
wouldn't be very useful here.

Cheers,
Ben.