From mboxrd@z Thu Jan  1 00:00:00 1970
From: Radim =?utf-8?B?S3LEjW3DocWZ?= <rkrcmar@redhat.com>
Subject: Re: [PATCH kvm-unit-tests 2/7] lib/x86/smp: introduce on_cpus
Date: Wed, 7 Jun 2017 16:48:34 +0200
Message-ID: <20170607144833.GH28750@potion>
References: <20170601154819.18831-1-drjones@redhat.com>
 <20170601154819.18831-3-drjones@redhat.com>
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To: Andrew Jones <drjones@redhat.com>
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2017-06-01 17:48+0200, Andrew Jones:
> Signed-off-by: Andrew Jones <drjones@redhat.com>
> ---
> diff --git a/lib/x86/smp.c b/lib/x86/smp.c
> @@ -1,5 +1,6 @@
> @@ -91,6 +95,21 @@ void on_cpu_async(int cpu, void (*function)(void *data), void *data)
>      __on_cpu(cpu, function, data, 0);
>  }
>  

(I'm sorry the review took so long.)

> +void on_cpus(void (*func)(void))
> +{
> +    int cpu;
> +
> +    for (cpu = cpu_count() - 1; cpu >= 0; --cpu)
> +        on_cpu_async(cpu, (ipi_function_type)func, NULL);

Calling a casted function pointer is undefined behavior in C and I think
that keeping the argument is better anyway -- the API is consistent that
way and you don't need to introduce a global in some patches.

> +
> +    while (cpus_active())
> +        ;

Add a pause() here,

Thanks.