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Date: Wed, 26 May 2010 12:08:48 +0200
From: Frederic Weisbecker <fweisbec@gmail.com>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>, Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>,
       Arnaldo Carvalho de Melo <acme@infradead.org>,
       Steven Rostedt <rostedt@goodmis.org>,
       David Miller <davem@davemloft.net>, Paul Mundt <lethal@linux-sh.org>,
       Will Deacon <will.deacon@arm.com>,
       Deng-Cheng Zhu <dengcheng.zhu@gmail.com>,
       LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 0/4] convert perf to local64_t
Message-ID: <20100526100844.GB5311@nowhere>
References: <20100521134205.781916350@chello.nl>
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On Fri, May 21, 2010 at 03:42:05PM +0200, Peter Zijlstra wrote:
> These patches introduce local64_t.
> 
> Since perf_event:count is only modified cross-cpu when child-counters
> feed back their changes on exit, and we can use a secondary variable
> for that, we can convert perf to use local64_t instead of atomic64_t
> and use instructions without buslock semantics.
> 
> The local64_t implementation uses local_t for 64 bits, since local_t is
> of type long, for 32 bit it falls back to atomic64_t. Architectures can
> provide their own implementation as usual.


It seems nobody disagrees with it. Can we give it a try?

Thanks.