linux-kernel - Re: [PATCH linux-next] KVM: x86: remove redundant ret variable

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Message-ID: <Y8hWqgF6ZQdVF5pP@google.com>
Date:   Wed, 18 Jan 2023 20:29:30 +0000
From:   Sean Christopherson <seanjc@...gle.com>
To:     zhang.songyi@....com.cn
Cc:     pbonzini@...hat.com, tglx@...utronix.de, mingo@...hat.com,
        bp@...en8.de, dave.hansen@...ux.intel.com, x86@...nel.org,
        hpa@...or.com, kvm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH linux-next] KVM: x86: remove redundant ret variable

On Wed, Nov 23, 2022, zhang.songyi@....com.cn wrote:
> From: zhang songyi <zhang.songyi@....com.cn>
> 
> Return value from apic_get_tmcct() directly instead of taking
> this in another redundant variable.
> 
> Signed-off-by: zhang songyi <zhang.songyi@....com.cn>
> ---
>  arch/x86/kvm/lapic.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
> index d7639d126e6c..707970804502 100644
> --- a/arch/x86/kvm/lapic.c
> +++ b/arch/x86/kvm/lapic.c
> @@ -1363,7 +1363,6 @@ static u32 apic_get_tmcct(struct kvm_lapic *apic)
>  {
>         ktime_t remaining, now;
>         s64 ns;
> -       u32 tmcct;
> 
>         ASSERT(apic != NULL);
> 
> @@ -1378,10 +1377,9 @@ static u32 apic_get_tmcct(struct kvm_lapic *apic)
>                 remaining = 0;
> 
>         ns = mod_64(ktime_to_ns(remaining), apic->lapic_timer.period);
> -       tmcct = div64_u64(ns,
> -                        (APIC_BUS_CYCLE_NS * apic->divide_count));
> 
> -       return tmcct;
> +       return div64_u64(ns,
> +                       (APIC_BUS_CYCLE_NS * apic->divide_count));

No need to wrap here, this fits comfortably on a single line (so does the
existing code, i.e. not your "bug").  No need for v2, I'll fix up when applying.