* [PATCH] x86/smp: Unused value freq_scale
@ 2021-09-10 18:44 Tim Gardner
2021-09-15 7:12 ` Giovanni Gherdovich
2021-09-17 19:27 ` [tip: x86/cleanups] x86/smp: Remove unnecessary assignment to local var freq_scale tip-bot2 for Tim Gardner
0 siblings, 2 replies; 3+ messages in thread
From: Tim Gardner @ 2021-09-10 18:44 UTC (permalink / raw)
To: x86
Cc: tim.gardner, Thomas Gleixner, Ingo Molnar, Borislav Petkov,
H. Peter Anvin, Peter Zijlstra (Intel),
Giovanni Gherdovich, Rafael J. Wysocki, Vitaly Kuznetsov,
Alison Schofield, Nathan Fontenot, Balbir Singh, linux-kernel
Coverity warns of an unused value in arch_scale_freq_tick().
CID 100778 (#1 of 1): Unused value (UNUSED_VALUE)
assigned_value: Assigning value 1024ULL to freq_scale here, but that stored
value is overwritten before it can be used.
e2b0d619b400a ("x86, sched: check for counters overflow in frequency invariant
accounting") introduced this warning.
Fix this by removing the variable initializer.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Giovanni Gherdovich <ggherdovich@suse.cz>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Nathan Fontenot <nathan.fontenot@amd.com>
Cc: Balbir Singh <sblbir@amazon.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
---
arch/x86/kernel/smpboot.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 85f6e242b6b4..c453b825a57f 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -2166,7 +2166,7 @@ DEFINE_PER_CPU(unsigned long, arch_freq_scale) = SCHED_CAPACITY_SCALE;
void arch_scale_freq_tick(void)
{
- u64 freq_scale = SCHED_CAPACITY_SCALE;
+ u64 freq_scale;
u64 aperf, mperf;
u64 acnt, mcnt;
--
2.33.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] x86/smp: Unused value freq_scale
2021-09-10 18:44 [PATCH] x86/smp: Unused value freq_scale Tim Gardner
@ 2021-09-15 7:12 ` Giovanni Gherdovich
2021-09-17 19:27 ` [tip: x86/cleanups] x86/smp: Remove unnecessary assignment to local var freq_scale tip-bot2 for Tim Gardner
1 sibling, 0 replies; 3+ messages in thread
From: Giovanni Gherdovich @ 2021-09-15 7:12 UTC (permalink / raw)
To: Tim Gardner, x86
Cc: Thomas Gleixner, Ingo Molnar, Borislav Petkov, H. Peter Anvin,
Peter Zijlstra (Intel),
Rafael J. Wysocki, Vitaly Kuznetsov, Alison Schofield,
Nathan Fontenot, Balbir Singh, linux-kernel
On Fri, 2021-09-10 at 12:44 -0600, Tim Gardner wrote:
> Coverity warns of an unused value in arch_scale_freq_tick().
>
> CID 100778 (#1 of 1): Unused value (UNUSED_VALUE)
> assigned_value: Assigning value 1024ULL to freq_scale here, but that stored
> value is overwritten before it can be used.
>
> e2b0d619b400a ("x86, sched: check for counters overflow in frequency invariant
> accounting") introduced this warning.
>
> Fix this by removing the variable initializer.
>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Borislav Petkov <bp@alien8.de>
> Cc: x86@kernel.org
> Cc: "H. Peter Anvin" <hpa@zytor.com>
> Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
> Cc: Giovanni Gherdovich <ggherdovich@suse.cz>
> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
> Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
> Cc: Alison Schofield <alison.schofield@intel.com>
> Cc: Nathan Fontenot <nathan.fontenot@amd.com>
> Cc: Balbir Singh <sblbir@amazon.com>
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
> ---
> arch/x86/kernel/smpboot.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
> index 85f6e242b6b4..c453b825a57f 100644
> --- a/arch/x86/kernel/smpboot.c
> +++ b/arch/x86/kernel/smpboot.c
> @@ -2166,7 +2166,7 @@ DEFINE_PER_CPU(unsigned long, arch_freq_scale) = SCHED_CAPACITY_SCALE;
>
> void arch_scale_freq_tick(void)
> {
> - u64 freq_scale = SCHED_CAPACITY_SCALE;
> + u64 freq_scale;
> u64 aperf, mperf;
> u64 acnt, mcnt;
>
Reviewed-by: Giovanni Gherdovich <ggherdovich@suse.cz>
Thanks,
Giovanni
^ permalink raw reply [flat|nested] 3+ messages in thread
* [tip: x86/cleanups] x86/smp: Remove unnecessary assignment to local var freq_scale
2021-09-10 18:44 [PATCH] x86/smp: Unused value freq_scale Tim Gardner
2021-09-15 7:12 ` Giovanni Gherdovich
@ 2021-09-17 19:27 ` tip-bot2 for Tim Gardner
1 sibling, 0 replies; 3+ messages in thread
From: tip-bot2 for Tim Gardner @ 2021-09-17 19:27 UTC (permalink / raw)
To: linux-tip-commits
Cc: Tim Gardner, Borislav Petkov, Giovanni Gherdovich, x86, linux-kernel
The following commit has been merged into the x86/cleanups branch of tip:
Commit-ID: 85784470efa2d5733e86679ba05d310ece81b20f
Gitweb: https://git.kernel.org/tip/85784470efa2d5733e86679ba05d310ece81b20f
Author: Tim Gardner <tim.gardner@canonical.com>
AuthorDate: Fri, 10 Sep 2021 12:44:05 -06:00
Committer: Borislav Petkov <bp@suse.de>
CommitterDate: Fri, 17 Sep 2021 21:20:34 +02:00
x86/smp: Remove unnecessary assignment to local var freq_scale
Coverity warns of an unused value in arch_scale_freq_tick():
CID 100778 (#1 of 1): Unused value (UNUSED_VALUE)
assigned_value: Assigning value 1024ULL to freq_scale here, but that stored
value is overwritten before it can be used.
It was introduced by commit:
e2b0d619b400a ("x86, sched: check for counters overflow in frequency invariant accounting")
Remove the variable initializer.
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Giovanni Gherdovich <ggherdovich@suse.cz>
Link: https://lkml.kernel.org/r/20210910184405.24422-1-tim.gardner@canonical.com
---
arch/x86/kernel/smpboot.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 85f6e24..c453b82 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -2166,7 +2166,7 @@ DEFINE_PER_CPU(unsigned long, arch_freq_scale) = SCHED_CAPACITY_SCALE;
void arch_scale_freq_tick(void)
{
- u64 freq_scale = SCHED_CAPACITY_SCALE;
+ u64 freq_scale;
u64 aperf, mperf;
u64 acnt, mcnt;
^ permalink raw reply related [flat|nested] 3+ messages in thread
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2021-09-10 18:44 [PATCH] x86/smp: Unused value freq_scale Tim Gardner
2021-09-15 7:12 ` Giovanni Gherdovich
2021-09-17 19:27 ` [tip: x86/cleanups] x86/smp: Remove unnecessary assignment to local var freq_scale tip-bot2 for Tim Gardner
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