On 25 May 2014 15:22, Preeti U Murthy preeti@linux.vnet.ibm.com wrote:
Hi Vincent,
Why do we have two interfaces arch_scale_freq_power() and arch_scale_cpu_power()? Does it make sense to consolidate them now ?
Hi Preeti,
They don't have the same purpose. arch_scale_cpu_power set the max capacity of your CPU whereas arch_scale_freq_power can be used to give the current capacity. ARM platform were using arch_scale_freq_power because it was the only one available for non SMT system but this induces some misunderstanding and some limitation in the characterization of a CPUs. This consolidation is a necessary step so we can now have the max capacity of a CPU and let arch_scale_freq_power for other purpose (or even remove it if useless).
Regards, Vincent
Regards Preeti U Murthy
On 05/23/2014 09:22 PM, Vincent Guittot wrote:
Use the new arch_scale_cpu_power in order to reflect the original capacity of a CPU instead of arch_scale_freq_power which is more linked to a scaling of the capacity linked to the frequency.
Signed-off-by: Vincent Guittot vincent.guittot@linaro.org
arch/arm/kernel/topology.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c index 71e1fec..6cc25a8 100644 --- a/arch/arm/kernel/topology.c +++ b/arch/arm/kernel/topology.c @@ -42,7 +42,7 @@ */ static DEFINE_PER_CPU(unsigned long, cpu_scale);
-unsigned long arch_scale_freq_power(struct sched_domain *sd, int cpu) +unsigned long arch_scale_cpu_power(struct sched_domain *sd, int cpu) { return per_cpu(cpu_scale, cpu); } @@ -166,7 +166,7 @@ static void update_cpu_power(unsigned int cpu) set_power_scale(cpu, cpu_capacity(cpu) / middle_capacity);
printk(KERN_INFO "CPU%u: update cpu_power %lu\n",
cpu, arch_scale_freq_power(NULL, cpu));
cpu, arch_scale_cpu_power(NULL, cpu));}
#else