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From: Richard Henderson <rth@twiddle.net>
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Subject: Re: [Qemu-devel] [PATCH 16/16] cpus-common: lock-free fast path for
 cpu_exec_start/end
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To: Paolo Bonzini <pbonzini@redhat.com>, qemu-devel@nongnu.org
Cc: serge.fdrv@gmail.com, cota@braap.org, alex.bennee@linaro.org, sergey.fedorov@linaro.org

On 09/23/2016 12:31 AM, Paolo Bonzini wrote:
> +        if (atomic_read(&other_cpu->running)) {
...
> +    atomic_set(&cpu->running, true);
...
> +            cpu->running = false;
...
> +            cpu->running = true;

Inconsistent use of atomics.  I don't see that the cpu_list_lock protects the 
last two lines in any way.


r~