2022-09-19 02:14:14

by Li zeming

Subject: [PATCH] asm-generic: Remove unnecessary ‘0’ values from guest_id

The file variable is assigned guest_id, it does not need to be initialized.

Signed-off-by: Li zeming <[email protected]>
---
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);
--
2.18.2

2022-09-19 16:01:38

by Vitaly Kuznetsov

Subject: Re: [PATCH] asm-generic: Remove unnecessary ‘0’ values from guest_id

Li zeming <[email protected]> writes:

> The file variable is assigned guest_id, it does not need to be initialized.
>
> Signed-off-by: Li zeming <[email protected]>
> ---
> 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

2022-09-20 01:40:39

by Li zeming

Subject: Re: [PATCH] asm-generic: Remove unnecessary ‘0’ values from guest_id

Thank you very much for your suggestion. I will submit the new version after passing the test code.