Messages in this thread | | | Date | Wed, 13 Jun 2012 10:50:59 +0200 | Subject | Re: [RFC 1/4] ARM: topology: Add arch_scale_freq_power function | From | Jean Pihet <> |
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Hi Vincent,
On Tue, Jun 12, 2012 at 2:02 PM, Vincent Guittot <vincent.guittot@linaro.org> wrote: > Add infrastructure to be able to modify the cpu_power of each core > > Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> > --- > arch/arm/include/asm/topology.h | 2 ++ > arch/arm/kernel/topology.c | 36 +++++++++++++++++++++++++++++++++++- > 2 files changed, 37 insertions(+), 1 deletion(-) > > diff --git a/arch/arm/include/asm/topology.h b/arch/arm/include/asm/topology.h > index 58b8b84..78e4c85 100644 > --- a/arch/arm/include/asm/topology.h > +++ b/arch/arm/include/asm/topology.h > @@ -27,11 +27,13 @@ void init_cpu_topology(void); > void store_cpu_topology(unsigned int cpuid); > const struct cpumask *cpu_coregroup_mask(int cpu); > > +void set_power_scale(unsigned int cpu, unsigned long power); > #else > > static inline void init_cpu_topology(void) { } > static inline void store_cpu_topology(unsigned int cpuid) { } > > +static inline void set_power_scale(unsigned int cpu, unsigned long power) { } > #endif > > #include <asm-generic/topology.h> > diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c > index 8200dea..00301a7 100644 > --- a/arch/arm/kernel/topology.c > +++ b/arch/arm/kernel/topology.c > @@ -22,6 +22,35 @@ > #include <asm/cputype.h> > #include <asm/topology.h> > > +/* > + * cpu power scale management > + */ > + > +/* > + * cpu power table > + * This per cpu data structure describes the relative capacity of each core. > + * On a heteregenous system, cores don't have the same computation capacity > + * and we reflect that difference in the cpu_power field so the scheduler can > + * take this difference into account for load balance. A per cpu structure is > + * preferred because each cpu is mainly using its own cpu_power even it's not > + * always true because of nohz_idle_balance The end of the comment is unclear IMO; Can you give more details on the relation between cpu_power and nohz_idle_balance?
Regards, Jean -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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