Re: [PATCH v3 2/5] ARM: topology: factorize the update of sibling masks

[Namhyung Kim <namhyung@kernel.org>]

On Wed, 20 Jun 2012 17:19:19 +0200, Vincent Guittot wrote:
> This factorization has also been proposed in another patchset that has not been
> merged yet:
> http://lists.infradead.org/pipermail/linux-arm-kernel/2012-January/080873.html
> So, this patch could be dropped depending of the state of the other one.
>
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>

Reviewed-by: Namhyung Kim <namhyung@kernel.org>


> ---
>  arch/arm/kernel/topology.c |   48 +++++++++++++++++++++++++-------------------
>  1 file changed, 27 insertions(+), 21 deletions(-)
>
> diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c
> index 51f23b3..eb5fc81 100644
> --- a/arch/arm/kernel/topology.c
> +++ b/arch/arm/kernel/topology.c
> @@ -82,6 +82,32 @@ const struct cpumask *cpu_coregroup_mask(int cpu)
>  	return &cpu_topology[cpu].core_sibling;
>  }
>  
> +void update_siblings_masks(unsigned int cpuid)
> +{
> +	struct cputopo_arm *cpu_topo, *cpuid_topo = &cpu_topology[cpuid];
> +	int cpu;
> +
> +	/* update core and thread sibling masks */
> +	for_each_possible_cpu(cpu) {
> +		cpu_topo = &cpu_topology[cpu];
> +
> +		if (cpuid_topo->socket_id != cpu_topo->socket_id)
> +			continue;
> +
> +		cpumask_set_cpu(cpuid, &cpu_topo->core_sibling);
> +		if (cpu != cpuid)
> +			cpumask_set_cpu(cpu, &cpuid_topo->core_sibling);
> +
> +		if (cpuid_topo->core_id != cpu_topo->core_id)
> +			continue;
> +
> +		cpumask_set_cpu(cpuid, &cpu_topo->thread_sibling);
> +		if (cpu != cpuid)
> +			cpumask_set_cpu(cpu, &cpuid_topo->thread_sibling);
> +	}
> +	smp_wmb();
> +}
> +
>  /*
>   * store_cpu_topology is called at boot when only one cpu is running
>   * and with the mutex cpu_hotplug.lock locked, when several cpus have booted,
> @@ -91,7 +117,6 @@ void store_cpu_topology(unsigned int cpuid)
>  {
>  	struct cputopo_arm *cpuid_topo = &cpu_topology[cpuid];
>  	unsigned int mpidr;
> -	unsigned int cpu;
>  
>  	/* If the cpu topology has been already set, just return */
>  	if (cpuid_topo->core_id != -1)
> @@ -133,26 +158,7 @@ void store_cpu_topology(unsigned int cpuid)
>  		cpuid_topo->socket_id = -1;
>  	}
>  
> -	/* update core and thread sibling masks */
> -	for_each_possible_cpu(cpu) {
> -		struct cputopo_arm *cpu_topo = &cpu_topology[cpu];
> -
> -		if (cpuid_topo->socket_id == cpu_topo->socket_id) {
> -			cpumask_set_cpu(cpuid, &cpu_topo->core_sibling);
> -			if (cpu != cpuid)
> -				cpumask_set_cpu(cpu,
> -					&cpuid_topo->core_sibling);
> -
> -			if (cpuid_topo->core_id == cpu_topo->core_id) {
> -				cpumask_set_cpu(cpuid,
> -					&cpu_topo->thread_sibling);
> -				if (cpu != cpuid)
> -					cpumask_set_cpu(cpu,
> -						&cpuid_topo->thread_sibling);
> -			}
> -		}
> -	}
> -	smp_wmb();
> +	update_siblings_masks(cpuid);
>  
>  	printk(KERN_INFO "CPU%u: thread %d, cpu %d, socket %d, mpidr %x\n",
>  		cpuid, cpu_topology[cpuid].thread_id,