Re: [PATCH] arm64: perf: no need to initialise statics to 0

From: Mark Rutland
Date: Mon May 09 2022 - 04:57:32 EST


On Sun, May 08, 2022 at 10:23:12AM +0800, Jason Wang wrote:
> Static variables do not need to be initialised to 0, because compiler
> will initialise all uninitialised statics to 0. Thus, remove the
> unneeded initializations.
>
> Signed-off-by: Jason Wang <wangborong@xxxxxxxxxx>

I would strongly prefer that we leave this as-is.

There is no problem with explicitly initializing a static variable to 0, and it
clearly aligns with the cmpxchg arguments below. Removing the initialization
makes that *less* clear.

Thanks,
Mark.

> ---
> arch/arm64/kernel/perf_event.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c
> index cb69ff1e6138..919fdcf8fce6 100644
> --- a/arch/arm64/kernel/perf_event.c
> +++ b/arch/arm64/kernel/perf_event.c
> @@ -1226,7 +1226,7 @@ static struct ctl_table armv8_pmu_sysctl_table[] = {
>
> static void armv8_pmu_register_sysctl_table(void)
> {
> - static u32 tbl_registered = 0;
> + static u32 tbl_registered;
>
> if (!cmpxchg_relaxed(&tbl_registered, 0, 1))
> register_sysctl("kernel", armv8_pmu_sysctl_table);
> --
> 2.35.1
>
>