* [PATCH] KVM: Eliminate unused variable warning on uniprocessor configs
@ 2017-05-11 3:40 ` Paul Mackerras
0 siblings, 0 replies; 6+ messages in thread
From: Paul Mackerras @ 2017-05-11 3:40 UTC (permalink / raw)
To: Paolo Bonzini, kvm; +Cc: kvm-ppc
Commit 7a97cec26b94 ("KVM: mark requests that need synchronization",
2017-04-27) added a variable 'wait' to kvm_make_all_cpus_request(),
which is only consumed in calls to smp_call_function_many. When the
kernel is compiled with CONFIG_SMP=n, smp_call_function_many() turns
into a macro which doesn't use the 'wait' argument, leading to a
warning about the variable 'wait' being unused:
/home/paulus/kernel/kvm/arch/powerpc/kvm/../../../virt/kvm/kvm_main.c: In function ‘kvm_make_all_cpus_request’:
/home/paulus/kernel/kvm/arch/powerpc/kvm/../../../virt/kvm/kvm_main.c:195:7: error: unused variable ‘wait’ [-Werror=unused-variable]
bool wait = req & KVM_REQUEST_WAIT;
^
Since PPC compiles everything that gets built under arch/powerpc
with -Werror by default, this causes the build to fail.
This fixes it by adding a __maybe_unused annotation to the
declaration of 'wait'.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
---
virt/kvm/kvm_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index f0fe9d0..f72b8a0 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -192,7 +192,7 @@ bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req)
int i, cpu, me;
cpumask_var_t cpus;
bool called = true;
- bool wait = req & KVM_REQUEST_WAIT;
+ bool __maybe_unused wait = req & KVM_REQUEST_WAIT;
struct kvm_vcpu *vcpu;
zalloc_cpumask_var(&cpus, GFP_ATOMIC);
--
2.7.4
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH] KVM: Eliminate unused variable warning on uniprocessor configs
@ 2017-05-11 3:40 ` Paul Mackerras
0 siblings, 0 replies; 6+ messages in thread
From: Paul Mackerras @ 2017-05-11 3:40 UTC (permalink / raw)
To: Paolo Bonzini, kvm; +Cc: kvm-ppc
Commit 7a97cec26b94 ("KVM: mark requests that need synchronization",
2017-04-27) added a variable 'wait' to kvm_make_all_cpus_request(),
which is only consumed in calls to smp_call_function_many. When the
kernel is compiled with CONFIG_SMP=n, smp_call_function_many() turns
into a macro which doesn't use the 'wait' argument, leading to a
warning about the variable 'wait' being unused:
/home/paulus/kernel/kvm/arch/powerpc/kvm/../../../virt/kvm/kvm_main.c: In function ‘kvm_make_all_cpus_request’:
/home/paulus/kernel/kvm/arch/powerpc/kvm/../../../virt/kvm/kvm_main.c:195:7: error: unused variable ‘wait’ [-Werror=unused-variable]
bool wait = req & KVM_REQUEST_WAIT;
^
Since PPC compiles everything that gets built under arch/powerpc
with -Werror by default, this causes the build to fail.
This fixes it by adding a __maybe_unused annotation to the
declaration of 'wait'.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
---
virt/kvm/kvm_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index f0fe9d0..f72b8a0 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -192,7 +192,7 @@ bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req)
int i, cpu, me;
cpumask_var_t cpus;
bool called = true;
- bool wait = req & KVM_REQUEST_WAIT;
+ bool __maybe_unused wait = req & KVM_REQUEST_WAIT;
struct kvm_vcpu *vcpu;
zalloc_cpumask_var(&cpus, GFP_ATOMIC);
--
2.7.4
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] KVM: Eliminate unused variable warning on uniprocessor configs
2017-05-11 3:40 ` Paul Mackerras
@ 2017-05-11 7:44 ` Paolo Bonzini
-1 siblings, 0 replies; 6+ messages in thread
From: Paolo Bonzini @ 2017-05-11 7:44 UTC (permalink / raw)
To: Paul Mackerras, kvm; +Cc: kvm-ppc, linux-kernel
On 11/05/2017 05:40, Paul Mackerras wrote:
> When the
> kernel is compiled with CONFIG_SMP=n, smp_call_function_many() turns
> into a macro which doesn't use the 'wait' argument, leading to a
> warning about the variable 'wait' being unused:
>
> /home/paulus/kernel/kvm/arch/powerpc/kvm/../../../virt/kvm/kvm_main.c: In function ‘kvm_make_all_cpus_request’:
> /home/paulus/kernel/kvm/arch/powerpc/kvm/../../../virt/kvm/kvm_main.c:195:7: error: unused variable ‘wait’ [-Werror=unused-variable]
> bool wait = req & KVM_REQUEST_WAIT;
Maybe the macro should not be a macro:
diff --git a/include/linux/smp.h b/include/linux/smp.h
index 8e0cb7a0f836..899c72f0933f 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -128,17 +128,18 @@ static inline void smp_send_stop(void) { }
* These macros fold the SMP functionality into a single CPU system
*/
#define raw_smp_processor_id() 0
-static inline int up_smp_call_function(smp_call_func_t func, void *info)
+static inline void smp_call_function_many(const struct cpumask *mask,
+ smp_call_func_t func, void *info,
+ bool wait);
{
- return 0;
+}
+
+static inline void smp_call_function(smp_call_func_t func, void *info, bool wait);
+{
}
-#define smp_call_function(func, info, wait) \
- (up_smp_call_function(func, info))
static inline void smp_send_reschedule(int cpu) { }
#define smp_prepare_boot_cpu() do {} while (0)
-#define smp_call_function_many(mask, func, info, wait) \
- (up_smp_call_function(func, info))
static inline void call_function_init(void) { }
static inline int
Paolo
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] KVM: Eliminate unused variable warning on uniprocessor configs
@ 2017-05-11 7:44 ` Paolo Bonzini
0 siblings, 0 replies; 6+ messages in thread
From: Paolo Bonzini @ 2017-05-11 7:44 UTC (permalink / raw)
To: Paul Mackerras, kvm; +Cc: kvm-ppc, linux-kernel
On 11/05/2017 05:40, Paul Mackerras wrote:
> When the
> kernel is compiled with CONFIG_SMP=n, smp_call_function_many() turns
> into a macro which doesn't use the 'wait' argument, leading to a
> warning about the variable 'wait' being unused:
>
> /home/paulus/kernel/kvm/arch/powerpc/kvm/../../../virt/kvm/kvm_main.c: In function ‘kvm_make_all_cpus_request’:
> /home/paulus/kernel/kvm/arch/powerpc/kvm/../../../virt/kvm/kvm_main.c:195:7: error: unused variable ‘wait’ [-Werror=unused-variable]
> bool wait = req & KVM_REQUEST_WAIT;
Maybe the macro should not be a macro:
diff --git a/include/linux/smp.h b/include/linux/smp.h
index 8e0cb7a0f836..899c72f0933f 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -128,17 +128,18 @@ static inline void smp_send_stop(void) { }
* These macros fold the SMP functionality into a single CPU system
*/
#define raw_smp_processor_id() 0
-static inline int up_smp_call_function(smp_call_func_t func, void *info)
+static inline void smp_call_function_many(const struct cpumask *mask,
+ smp_call_func_t func, void *info,
+ bool wait);
{
- return 0;
+}
+
+static inline void smp_call_function(smp_call_func_t func, void *info, bool wait);
+{
}
-#define smp_call_function(func, info, wait) \
- (up_smp_call_function(func, info))
static inline void smp_send_reschedule(int cpu) { }
#define smp_prepare_boot_cpu() do {} while (0)
-#define smp_call_function_many(mask, func, info, wait) \
- (up_smp_call_function(func, info))
static inline void call_function_init(void) { }
static inline int
Paolo
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] KVM: Eliminate unused variable warning on uniprocessor configs
2017-05-11 7:44 ` Paolo Bonzini
@ 2017-05-12 6:10 ` Paul Mackerras
-1 siblings, 0 replies; 6+ messages in thread
From: Paul Mackerras @ 2017-05-12 6:10 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: kvm, kvm-ppc, linux-kernel
On Thu, May 11, 2017 at 09:44:06AM +0200, Paolo Bonzini wrote:
>
>
> On 11/05/2017 05:40, Paul Mackerras wrote:
> > When the
> > kernel is compiled with CONFIG_SMP=n, smp_call_function_many() turns
> > into a macro which doesn't use the 'wait' argument, leading to a
> > warning about the variable 'wait' being unused:
> >
> > /home/paulus/kernel/kvm/arch/powerpc/kvm/../../../virt/kvm/kvm_main.c: In function ‘kvm_make_all_cpus_request’:
> > /home/paulus/kernel/kvm/arch/powerpc/kvm/../../../virt/kvm/kvm_main.c:195:7: error: unused variable ‘wait’ [-Werror=unused-variable]
> > bool wait = req & KVM_REQUEST_WAIT;
>
> Maybe the macro should not be a macro:
Sounds fair, and with a couple of semicolons removed, it works and
fixes the problem. Do you want to send it to the appropriate
maintainer(s) or will I?
> diff --git a/include/linux/smp.h b/include/linux/smp.h
> index 8e0cb7a0f836..899c72f0933f 100644
> --- a/include/linux/smp.h
> +++ b/include/linux/smp.h
> @@ -128,17 +128,18 @@ static inline void smp_send_stop(void) { }
> * These macros fold the SMP functionality into a single CPU system
> */
> #define raw_smp_processor_id() 0
> -static inline int up_smp_call_function(smp_call_func_t func, void *info)
> +static inline void smp_call_function_many(const struct cpumask *mask,
> + smp_call_func_t func, void *info,
> + bool wait);
No semicolon on the end of this line...
> {
> - return 0;
> +}
> +
> +static inline void smp_call_function(smp_call_func_t func, void *info, bool wait);
or this one.
Paul.
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] KVM: Eliminate unused variable warning on uniprocessor configs
@ 2017-05-12 6:10 ` Paul Mackerras
0 siblings, 0 replies; 6+ messages in thread
From: Paul Mackerras @ 2017-05-12 6:10 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: kvm, kvm-ppc, linux-kernel
On Thu, May 11, 2017 at 09:44:06AM +0200, Paolo Bonzini wrote:
>
>
> On 11/05/2017 05:40, Paul Mackerras wrote:
> > When the
> > kernel is compiled with CONFIG_SMP=n, smp_call_function_many() turns
> > into a macro which doesn't use the 'wait' argument, leading to a
> > warning about the variable 'wait' being unused:
> >
> > /home/paulus/kernel/kvm/arch/powerpc/kvm/../../../virt/kvm/kvm_main.c: In function ‘kvm_make_all_cpus_request’:
> > /home/paulus/kernel/kvm/arch/powerpc/kvm/../../../virt/kvm/kvm_main.c:195:7: error: unused variable ‘wait’ [-Werror=unused-variable]
> > bool wait = req & KVM_REQUEST_WAIT;
>
> Maybe the macro should not be a macro:
Sounds fair, and with a couple of semicolons removed, it works and
fixes the problem. Do you want to send it to the appropriate
maintainer(s) or will I?
> diff --git a/include/linux/smp.h b/include/linux/smp.h
> index 8e0cb7a0f836..899c72f0933f 100644
> --- a/include/linux/smp.h
> +++ b/include/linux/smp.h
> @@ -128,17 +128,18 @@ static inline void smp_send_stop(void) { }
> * These macros fold the SMP functionality into a single CPU system
> */
> #define raw_smp_processor_id() 0
> -static inline int up_smp_call_function(smp_call_func_t func, void *info)
> +static inline void smp_call_function_many(const struct cpumask *mask,
> + smp_call_func_t func, void *info,
> + bool wait);
No semicolon on the end of this line...
> {
> - return 0;
> +}
> +
> +static inline void smp_call_function(smp_call_func_t func, void *info, bool wait);
or this one.
Paul.
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2017-05-12 6:10 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2017-05-11 3:40 [PATCH] KVM: Eliminate unused variable warning on uniprocessor configs Paul Mackerras
2017-05-11 3:40 ` Paul Mackerras
2017-05-11 7:44 ` Paolo Bonzini
2017-05-11 7:44 ` Paolo Bonzini
2017-05-12 6:10 ` Paul Mackerras
2017-05-12 6:10 ` Paul Mackerras
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