2022-11-23 07:17:02

by Jiapeng Chong

Subject: [PATCH] x86/cacheinfo: Remove set but unused variable 'trace'

Variable 'trace' is not effectively used in the function, so delete it.

arch/x86/kernel/cpu/cacheinfo.c:737:15: warning: variable 'trace' set but not used.

Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=3243
Reported-by: Abaci Robot <[email protected]>
Signed-off-by: Jiapeng Chong <[email protected]>
---
arch/x86/kernel/cpu/cacheinfo.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/cacheinfo.c b/arch/x86/kernel/cpu/cacheinfo.c
index f4e5aa27eec6..c6c0052def8e 100644
--- a/arch/x86/kernel/cpu/cacheinfo.c
+++ b/arch/x86/kernel/cpu/cacheinfo.c
@@ -734,7 +734,7 @@ void init_hygon_cacheinfo(struct cpuinfo_x86 *c)
void init_intel_cacheinfo(struct cpuinfo_x86 *c)
{
/* Cache sizes */
- unsigned int trace = 0, l1i = 0, l1d = 0, l2 = 0, l3 = 0;
+ unsigned int l1i = 0, l1d = 0, l2 = 0, l3 = 0;
unsigned int new_l1d = 0, new_l1i = 0; /* Cache sizes from cpuid(4) */
unsigned int new_l2 = 0, new_l3 = 0, i; /* Cache sizes from cpuid(4) */
unsigned int l2_id = 0, l3_id = 0, num_threads_sharing, index_msb;
@@ -836,7 +836,6 @@ void init_intel_cacheinfo(struct cpuinfo_x86 *c)
l3 += cache_table[k].size;
break;
case LVL_TRACE:
- trace += cache_table[k].size;
break;
}

--
2.20.1.7.g153144c

2022-12-02 13:22:10

by Thomas Gleixner

Subject: Re: [PATCH] x86/cacheinfo: Remove set but unused variable 'trace'

On Wed, Nov 23 2022 at 14:01, Jiapeng Chong wrote:

> Variable 'trace' is not effectively used in the function, so delete it.
>
> arch/x86/kernel/cpu/cacheinfo.c:737:15: warning: variable 'trace' set but not used.
>
> Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=3243

This link is really pointless.

> Reported-by: Abaci Robot <[email protected]>
> Signed-off-by: Jiapeng Chong <[email protected]>
> ---
> arch/x86/kernel/cpu/cacheinfo.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/cacheinfo.c b/arch/x86/kernel/cpu/cacheinfo.c
> index f4e5aa27eec6..c6c0052def8e 100644
> --- a/arch/x86/kernel/cpu/cacheinfo.c
> +++ b/arch/x86/kernel/cpu/cacheinfo.c
> @@ -734,7 +734,7 @@ void init_hygon_cacheinfo(struct cpuinfo_x86 *c)
> void init_intel_cacheinfo(struct cpuinfo_x86 *c)
> {
> /* Cache sizes */
> - unsigned int trace = 0, l1i = 0, l1d = 0, l2 = 0, l3 = 0;
> + unsigned int l1i = 0, l1d = 0, l2 = 0, l3 = 0;
> unsigned int new_l1d = 0, new_l1i = 0; /* Cache sizes from cpuid(4) */
> unsigned int new_l2 = 0, new_l3 = 0, i; /* Cache sizes from cpuid(4) */
> unsigned int l2_id = 0, l3_id = 0, num_threads_sharing, index_msb;
> @@ -836,7 +836,6 @@ void init_intel_cacheinfo(struct cpuinfo_x86 *c)
> l3 += cache_table[k].size;
> break;
> case LVL_TRACE:
> - trace += cache_table[k].size;
> break;

Sure, that makes the warning go away, but what's the purpose of
'case LVL_TRACE:' now?

Now if you remove that you really want look at the surrounding logic of
LVL_TRACE. Hint: There is way more completely useless code to remove.

Thanks,

tglx