| Message ID | 20170726133447.2056379-1-arnd@arndb.de |
|---|---|
| State | New |
| Headers | show |
On 26/07/2017 15:32, Arnd Bergmann wrote: > A new caller of smp_call_function() passes a local variable as the 'wait' > argument, and that variable is otherwise unused, so we get a warning > in non-SMP configurations: > > virt/kvm/kvm_main.c: In function 'kvm_make_all_cpus_request': > virt/kvm/kvm_main.c:195:7: error: unused variable 'wait' [-Werror=unused-variable] > bool wait = req & KVM_REQUEST_WAIT; > > This addresses the warning by changing the two macros into inline functions. > As reported by the 0day build bot, a small change is required in the MIPS > r4k code for this, which then gets a warning about a missing variable. > > Fixes: 7a97cec26b94 ("KVM: mark requests that need synchronization") > Cc: Paolo Bonzini <pbonzini@redhat.com> > Link: https://patchwork.kernel.org/patch/9722063/ > Signed-off-by: Arnd Bergmann <arnd@arndb.de> This is not needed anymore, I've fixed it in KVM: commit b49defe83659cefbb1763d541e779da32594ab10 Author: Paolo Bonzini <pbonzini@redhat.com> Date: Fri Jun 30 13:25:45 2017 +0200 kvm: avoid unused variable warning for UP builds The uniprocessor version of smp_call_function_many does not evaluate all of its argument, and the compiler emits a warning about "wait" being unused. This breaks the build on architectures for which "-Werror" is enabled by default. Work around it by moving the invocation of smp_call_function_many to its own inline function. Reported-by: Paul Mackerras <paulus@ozlabs.org> Cc: stable@vger.kernel.org Fixes: 7a97cec26b94c909f4cbad2dc3186af3e457a522 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Paolo
On Wed, Jul 26, 2017 at 4:42 PM, Paolo Bonzini <pbonzini@redhat.com> wrote: > On 26/07/2017 15:32, Arnd Bergmann wrote: >> A new caller of smp_call_function() passes a local variable as the 'wait' >> argument, and that variable is otherwise unused, so we get a warning >> in non-SMP configurations: >> >> virt/kvm/kvm_main.c: In function 'kvm_make_all_cpus_request': >> virt/kvm/kvm_main.c:195:7: error: unused variable 'wait' [-Werror=unused-variable] >> bool wait = req & KVM_REQUEST_WAIT; >> >> This addresses the warning by changing the two macros into inline functions. >> As reported by the 0day build bot, a small change is required in the MIPS >> r4k code for this, which then gets a warning about a missing variable. >> >> Fixes: 7a97cec26b94 ("KVM: mark requests that need synchronization") >> Cc: Paolo Bonzini <pbonzini@redhat.com> >> Link: https://patchwork.kernel.org/patch/9722063/ >> Signed-off-by: Arnd Bergmann <arnd@arndb.de> > > This is not needed anymore, I've fixed it in KVM: > > commit b49defe83659cefbb1763d541e779da32594ab10 > Author: Paolo Bonzini <pbonzini@redhat.com> > Date: Fri Jun 30 13:25:45 2017 +0200 > > kvm: avoid unused variable warning for UP builds Ok, that seems sufficient, thanks! Arnd
diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c index 81d6a15c93d0..f353bf5f24f1 100644 --- a/arch/mips/mm/c-r4k.c +++ b/arch/mips/mm/c-r4k.c @@ -97,9 +97,11 @@ static inline void r4k_on_each_cpu(unsigned int type, void (*func)(void *info), void *info) { preempt_disable(); +#ifdef CONFIG_SMP if (r4k_op_needs_ipi(type)) smp_call_function_many(&cpu_foreign_map[smp_processor_id()], func, info, 1); +#endif func(info); preempt_enable(); } diff --git a/include/linux/smp.h b/include/linux/smp.h index 68123c1fe549..ea24e2d3504c 100644 --- a/include/linux/smp.h +++ b/include/linux/smp.h @@ -135,17 +135,19 @@ 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 int smp_call_function(smp_call_func_t func, void *info, int wait) { return 0; } -#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 smp_call_function_many(const struct cpumask *mask, + smp_call_func_t func, void *info, bool wait) +{ +} + static inline void call_function_init(void) { } static inline int
A new caller of smp_call_function() passes a local variable as the 'wait' argument, and that variable is otherwise unused, so we get a warning in non-SMP configurations: virt/kvm/kvm_main.c: In function 'kvm_make_all_cpus_request': virt/kvm/kvm_main.c:195:7: error: unused variable 'wait' [-Werror=unused-variable] bool wait = req & KVM_REQUEST_WAIT; This addresses the warning by changing the two macros into inline functions. As reported by the 0day build bot, a small change is required in the MIPS r4k code for this, which then gets a warning about a missing variable. Fixes: 7a97cec26b94 ("KVM: mark requests that need synchronization") Cc: Paolo Bonzini <pbonzini@redhat.com> Link: https://patchwork.kernel.org/patch/9722063/ Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- v2: - fix MIPS build error reported by kbuild test robot - remove up_smp_call_function() --- arch/mips/mm/c-r4k.c | 2 ++ include/linux/smp.h | 12 +++++++----- 2 files changed, 9 insertions(+), 5 deletions(-) -- 2.9.0