From mboxrd@z Thu Jan  1 00:00:00 1970
From: Glauber Costa <glommer@parallels.com>
Subject: Re: [patch 04/16] x86: pvclock: create helper for pvclock data retrieval
Date: Thu, 1 Nov 2012 18:04:02 +0400
Message-ID: <50928152.2060005@parallels.com>
References: <20121031224656.417434866@redhat.com> <20121031224824.003238142@redhat.com>
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Cc: <kvm@vger.kernel.org>, <johnstul@us.ibm.com>, <jeremy@goop.org>,
	<zamsden@gmail.com>, <gleb@redhat.com>, <avi@redhat.com>,
	<pbonzini@redhat.com>
To: Marcelo Tosatti <mtosatti@redhat.com>
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On 11/01/2012 02:47 AM, Marcelo Tosatti wrote:
> +static __always_inline
> +unsigned __pvclock_read_cycles(const struct pvclock_vcpu_time_info *src,
> +			       cycle_t *cycles, u8 *flags)
> +{
> +	unsigned version;
> +	cycle_t ret, offset;
> +	u8 ret_flags;
> +
> +	version = src->version;
> +	rdtsc_barrier();
> +	offset = pvclock_get_nsec_offset(src);
> +	ret = src->system_time + offset;
> +	ret_flags = src->flags;
> +	rdtsc_barrier();
> +
> +	*cycles = ret;
> +	*flags = ret_flags;
> +	return version;
> +}
> +
This interface is a bit weird.
The actual value you are interested in is "cycles", so why is it
returned through the parameters? I think it would be clearer to have
this return cycles, and &version as a parameter.