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From: Alex =?utf-8?Q?Benn=C3=A9e?= <alex.bennee@linaro.org>
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Date: Wed, 05 Oct 2016 12:46:00 +0100
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Subject: Re: [Qemu-devel] [PATCH v4 25/35] target-i386: remove helper_lock()
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To: Richard Henderson <rth@twiddle.net>
Cc: qemu-devel@nongnu.org, "Emilio G. Cota" <cota@braap.org>


Richard Henderson <rth@twiddle.net> writes:

> From: "Emilio G. Cota" <cota@braap.org>
>
> It's been superseded by the atomic helpers.
>
> The use of the atomic helpers provides a significant performance and scalability
> improvement. Below is the result of running the atomic_add-test microbenchmark with:
>  $ x86_64-linux-user/qemu-x86_64 tests/atomic_add-bench -o 5000000 -r $r -n $n
> , where $n is the number of threads and $r is the allowed range for the additions.
>
<snip>
>
> For master I stopped measuring master after 8 threads, because there is little
> point in measuring the well-known performance collapse of a contended lock.
>
> Signed-off-by: Emilio G. Cota <cota@braap.org>
> Message-Id: <1467054136-10430-21-git-send-email-cota@braap.org>
> Signed-off-by: Richard Henderson <rth@twiddle.net>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

--
Alex Bennée