Message ID | 20231018163751.2423181-4-srikar@linux.vnet.ibm.com (mailing list archive) |
---|---|
State | Superseded |
Headers | show |
Series | powerpc/smp: Shared processor sched optimizations | expand |
Srikar Dronamraju <srikar@linux.vnet.ibm.com> writes: > The ability to detect if the system is running in a shared processor > mode is helpful in few more generic cases not just in > paravirtualization. > For example: At boot time, different scheduler/ topology flags may be > set based on the processor mode. Hence move it to a more generic file. I'd rather you just included paravirt.h in the few files where you need it. cheers > diff --git a/arch/powerpc/include/asm/paravirt.h b/arch/powerpc/include/asm/paravirt.h > index 0372b0093f72..cf83e837a571 100644 > --- a/arch/powerpc/include/asm/paravirt.h > +++ b/arch/powerpc/include/asm/paravirt.h > @@ -15,13 +15,6 @@ > #include <asm/kvm_guest.h> > #include <asm/cputhreads.h> > > -DECLARE_STATIC_KEY_FALSE(shared_processor); > - > -static inline bool is_shared_processor(void) > -{ > - return static_branch_unlikely(&shared_processor); > -} > - > #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING > extern struct static_key paravirt_steal_enabled; > extern struct static_key paravirt_steal_rq_enabled; > @@ -77,11 +70,6 @@ static inline bool is_vcpu_idle(int vcpu) > return lppaca_of(vcpu).idle; > } > #else > -static inline bool is_shared_processor(void) > -{ > - return false; > -} > - > static inline u32 yield_count_of(int cpu) > { > return 0; > diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h > index aaaa576d0e15..08631b2a4528 100644 > --- a/arch/powerpc/include/asm/smp.h > +++ b/arch/powerpc/include/asm/smp.h > @@ -34,6 +34,20 @@ extern bool coregroup_enabled; > extern int cpu_to_chip_id(int cpu); > extern int *chip_id_lookup_table; > > +#ifdef CONFIG_PPC_SPLPAR > +DECLARE_STATIC_KEY_FALSE(shared_processor); > + > +static inline bool is_shared_processor(void) > +{ > + return static_branch_unlikely(&shared_processor); > +} > +#else > +static inline bool is_shared_processor(void) > +{ > + return false; > +} > +#endif > + > DECLARE_PER_CPU(cpumask_var_t, thread_group_l1_cache_map); > DECLARE_PER_CPU(cpumask_var_t, thread_group_l2_cache_map); > DECLARE_PER_CPU(cpumask_var_t, thread_group_l3_cache_map); > -- > 2.31.1
On 10/18/23 10:07 PM, Srikar Dronamraju wrote: > The ability to detect if the system is running in a shared processor > mode is helpful in few more generic cases not just in > paravirtualization. > For example: At boot time, different scheduler/ topology flags may be > set based on the processor mode. Hence move it to a more generic file. > > Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> > --- > arch/powerpc/include/asm/paravirt.h | 12 ------------ > arch/powerpc/include/asm/smp.h | 14 ++++++++++++++ > 2 files changed, 14 insertions(+), 12 deletions(-) > > diff --git a/arch/powerpc/include/asm/paravirt.h b/arch/powerpc/include/asm/paravirt.h > index 0372b0093f72..cf83e837a571 100644 > --- a/arch/powerpc/include/asm/paravirt.h > +++ b/arch/powerpc/include/asm/paravirt.h > @@ -15,13 +15,6 @@ > #include <asm/kvm_guest.h> > #include <asm/cputhreads.h> > > -DECLARE_STATIC_KEY_FALSE(shared_processor); > - > -static inline bool is_shared_processor(void) > -{ > - return static_branch_unlikely(&shared_processor); > -} > - > #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING > extern struct static_key paravirt_steal_enabled; > extern struct static_key paravirt_steal_rq_enabled; > @@ -77,11 +70,6 @@ static inline bool is_vcpu_idle(int vcpu) > return lppaca_of(vcpu).idle; > } Hi Srikar, This patch fails to apply on tip/master as it depends on https://lore.kernel.org/all/20231019091452.95260-1-srikar@linux.vnet.ibm.com/ to be applied first. > #else > -static inline bool is_shared_processor(void) > -{ > - return false; > -} > - > static inline u32 yield_count_of(int cpu) > { > return 0; > diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h > index aaaa576d0e15..08631b2a4528 100644 > --- a/arch/powerpc/include/asm/smp.h > +++ b/arch/powerpc/include/asm/smp.h > @@ -34,6 +34,20 @@ extern bool coregroup_enabled; > extern int cpu_to_chip_id(int cpu); > extern int *chip_id_lookup_table; > > +#ifdef CONFIG_PPC_SPLPAR > +DECLARE_STATIC_KEY_FALSE(shared_processor); > + > +static inline bool is_shared_processor(void) > +{ > + return static_branch_unlikely(&shared_processor); > +} > +#else > +static inline bool is_shared_processor(void) > +{ > + return false; > +} > +#endif > + > DECLARE_PER_CPU(cpumask_var_t, thread_group_l1_cache_map); > DECLARE_PER_CPU(cpumask_var_t, thread_group_l2_cache_map); > DECLARE_PER_CPU(cpumask_var_t, thread_group_l3_cache_map);
* Michael Ellerman <mpe@ellerman.id.au> [2023-10-19 15:41:40]: > Srikar Dronamraju <srikar@linux.vnet.ibm.com> writes: > > The ability to detect if the system is running in a shared processor > > mode is helpful in few more generic cases not just in > > paravirtualization. > > For example: At boot time, different scheduler/ topology flags may be > > set based on the processor mode. Hence move it to a more generic file. > > I'd rather you just included paravirt.h in the few files where you need it. I thought, detecting if a Processor was shared or not was more a smp/processor related than a paravirt related. Will drop as suggested. > > cheers > > > diff --git a/arch/powerpc/include/asm/paravirt.h b/arch/powerpc/include/asm/paravirt.h > > index 0372b0093f72..cf83e837a571 100644 > > --- a/arch/powerpc/include/asm/paravirt.h > > +++ b/arch/powerpc/include/asm/paravirt.h > > @@ -15,13 +15,6 @@ > > #include <asm/kvm_guest.h> > > #include <asm/cputhreads.h> > > > > -DECLARE_STATIC_KEY_FALSE(shared_processor); > > - > > -static inline bool is_shared_processor(void) > > -{ > > - return static_branch_unlikely(&shared_processor); > > -} > > - > > #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING > > extern struct static_key paravirt_steal_enabled; > > extern struct static_key paravirt_steal_rq_enabled; > > @@ -77,11 +70,6 @@ static inline bool is_vcpu_idle(int vcpu) > > return lppaca_of(vcpu).idle; > > } > > #else > > -static inline bool is_shared_processor(void) > > -{ > > - return false; > > -} > > - > > static inline u32 yield_count_of(int cpu) > > { > > return 0; > > diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h > > index aaaa576d0e15..08631b2a4528 100644 > > --- a/arch/powerpc/include/asm/smp.h > > +++ b/arch/powerpc/include/asm/smp.h > > @@ -34,6 +34,20 @@ extern bool coregroup_enabled; > > extern int cpu_to_chip_id(int cpu); > > extern int *chip_id_lookup_table; > > > > +#ifdef CONFIG_PPC_SPLPAR > > +DECLARE_STATIC_KEY_FALSE(shared_processor); > > + > > +static inline bool is_shared_processor(void) > > +{ > > + return static_branch_unlikely(&shared_processor); > > +} > > +#else > > +static inline bool is_shared_processor(void) > > +{ > > + return false; > > +} > > +#endif > > + > > DECLARE_PER_CPU(cpumask_var_t, thread_group_l1_cache_map); > > DECLARE_PER_CPU(cpumask_var_t, thread_group_l2_cache_map); > > DECLARE_PER_CPU(cpumask_var_t, thread_group_l3_cache_map); > > -- > > 2.31.1
Srikar Dronamraju <srikar@linux.vnet.ibm.com> writes: > * Michael Ellerman <mpe@ellerman.id.au> [2023-10-19 15:41:40]: > >> Srikar Dronamraju <srikar@linux.vnet.ibm.com> writes: >> > The ability to detect if the system is running in a shared processor >> > mode is helpful in few more generic cases not just in >> > paravirtualization. >> > For example: At boot time, different scheduler/ topology flags may be >> > set based on the processor mode. Hence move it to a more generic file. >> >> I'd rather you just included paravirt.h in the few files where you need it. > > I thought, detecting if a Processor was shared or not was more a > smp/processor related than a paravirt related. It's both really :) It's definitely paravirt related though, because if we weren't *para*virt then we wouldn't know there was a hypervisor at all :) But having smaller more focused headers is preferable in general just for mechanical reasons. cheers
diff --git a/arch/powerpc/include/asm/paravirt.h b/arch/powerpc/include/asm/paravirt.h index 0372b0093f72..cf83e837a571 100644 --- a/arch/powerpc/include/asm/paravirt.h +++ b/arch/powerpc/include/asm/paravirt.h @@ -15,13 +15,6 @@ #include <asm/kvm_guest.h> #include <asm/cputhreads.h> -DECLARE_STATIC_KEY_FALSE(shared_processor); - -static inline bool is_shared_processor(void) -{ - return static_branch_unlikely(&shared_processor); -} - #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING extern struct static_key paravirt_steal_enabled; extern struct static_key paravirt_steal_rq_enabled; @@ -77,11 +70,6 @@ static inline bool is_vcpu_idle(int vcpu) return lppaca_of(vcpu).idle; } #else -static inline bool is_shared_processor(void) -{ - return false; -} - static inline u32 yield_count_of(int cpu) { return 0; diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h index aaaa576d0e15..08631b2a4528 100644 --- a/arch/powerpc/include/asm/smp.h +++ b/arch/powerpc/include/asm/smp.h @@ -34,6 +34,20 @@ extern bool coregroup_enabled; extern int cpu_to_chip_id(int cpu); extern int *chip_id_lookup_table; +#ifdef CONFIG_PPC_SPLPAR +DECLARE_STATIC_KEY_FALSE(shared_processor); + +static inline bool is_shared_processor(void) +{ + return static_branch_unlikely(&shared_processor); +} +#else +static inline bool is_shared_processor(void) +{ + return false; +} +#endif + DECLARE_PER_CPU(cpumask_var_t, thread_group_l1_cache_map); DECLARE_PER_CPU(cpumask_var_t, thread_group_l2_cache_map); DECLARE_PER_CPU(cpumask_var_t, thread_group_l3_cache_map);
The ability to detect if the system is running in a shared processor mode is helpful in few more generic cases not just in paravirtualization. For example: At boot time, different scheduler/ topology flags may be set based on the processor mode. Hence move it to a more generic file. Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> --- arch/powerpc/include/asm/paravirt.h | 12 ------------ arch/powerpc/include/asm/smp.h | 14 ++++++++++++++ 2 files changed, 14 insertions(+), 12 deletions(-)