Re: [PATCH v2 3/6] powerpc/smp: Move shared_processor static key to smp.h

Shrikanth Hegde
2023-10-19T11:03:10Z

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);