Re: [PATCH 1/3] perf bench: Add wrappers for atomic operation of GCC

Darren Hart
2009-11-24T16:20:20Z

Hitoshi Mitake wrote:
> This patch adds new file util/include/asm/atomic.h.
> It contains wrappers for atomic operation of GCC,
> I think this is useful not only for 'perf bench',
> but also for entire of perf command.
>
> This patch adds new typedefed struct 'atomic_t'.
> I know new typedef is not a thing to welcome,
> but I believe that atomic_t is worth to typedef
> because it is much general.
>
> I borrowed this file from Darren Hart's futextest.
> http://git.kernel.org/?p=linux/kernel/git/dvhart/futextest.git

Hi Hitoshi-san,

I took the gcc built-ins approach for futextest.h because I didn't want
the hassle of maintaining per-arch asm files. Since perf is already in
the kernel source, I wonder if you could leverage the already existing
kernel atomic code? See Documentation/atomic_ops.txt.

>
> Signed-off-by: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
> Cc: Michel Lespinasse <walken@google.com>
> Cc: Darren Hart <dvhltc@us.ibm.com>
> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Frederic Weisbecker <fweisbec@gmail.com>
> ---
> tools/perf/util/include/asm/atomic.h | 91 ++++++++++++++++++++++++++++++++++
> 1 files changed, 91 insertions(+), 0 deletions(-)
> create mode 100644 tools/perf/util/include/asm/atomic.h
>
> diff --git a/tools/perf/util/include/asm/atomic.h b/tools/perf/util/include/asm/atomic.h
> new file mode 100644
> index 0000000..1cef451
> --- /dev/null
> +++ b/tools/perf/util/include/asm/atomic.h
> @@ -0,0 +1,91 @@
> +/******************************************************************************
> + *
> + * Copyright B) International Business Machines Corp., 2009

B) should be © (or (C) at the very least), I'm guessing character set issue?

Thanks,

--
Darren Hart
IBM Linux Technology Center
Real-Time Linux Team