linux-kernel - Re: [PATCH] asm-generic: Remove unnecessary ‘0’ values from guest

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Message-ID: <878rmfpef8.fsf@redhat.com>
Date:   Mon, 19 Sep 2022 17:33:15 +0200
From:   Vitaly Kuznetsov <vkuznets@...hat.com>
To:     Li zeming <zeming@...china.com>
Cc:     linux-hyperv@...r.kernel.org, linux-arch@...r.kernel.org,
        linux-kernel@...r.kernel.org, Li zeming <zeming@...china.com>,
        kys@...rosoft.com, haiyangz@...rosoft.com, wei.liu@...nel.org
Subject: Re: [PATCH] asm-generic: Remove unnecessary ‘0’ values from guest_id

Li zeming <zeming@...china.com> writes:

> The file variable is assigned guest_id, it does not need to be initialized.
>
> Signed-off-by: Li zeming <zeming@...china.com>
> ---
>  include/asm-generic/mshyperv.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
> index c05d2ce9b6cd..cd5ce86c218a 100644
> --- a/include/asm-generic/mshyperv.h
> +++ b/include/asm-generic/mshyperv.h
> @@ -108,7 +108,7 @@ static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size,
>  static inline  __u64 generate_guest_id(__u64 d_info1, __u64 kernel_version,
>  				       __u64 d_info2)
>  {
> -	__u64 guest_id = 0;
> +	__u64 guest_id;
>  
>  	guest_id = (((__u64)HV_LINUX_VENDOR_ID) << 48);
>  	guest_id |= (d_info1 << 48);

The initializer is certainly not needed, however, if we are to do some
changes, let's be bold. Suggestions:

1) Stop using "__u64" type, "u64" is good enough.

2) Drop all the parameters from the function, both call sites look like

 generate_guest_id(0, LINUX_VERSION_CODE, 0);

3) Rename the function to make it clear it's Hyper-V related,
e.g. "hv_generate_guest_id()".

...

-- 
Vitaly