Re: [PATCH v3 1/4] LoongArch: Move CONFIG_HAVE_SETUP_PER_CPU_AREA related code to smp.c

From: Tiezhu Yang
Date: Fri Apr 12 2024 - 05:27:47 EST




On 04/12/2024 12:12 PM, Huacai Chen wrote:
On Thu, Apr 11, 2024 at 9:05 AM Tiezhu Yang <yangtiezhu@xxxxxxxxxxx> wrote:

Currently, if CONFIG_NUMA is not set but CONFIG_SMP is set, the arch
specified setup_per_cpu_areas() in arch/loongarch/kernel/numa.c will
not be built and the generic setup_per_cpu_areas() in mm/percpu.c is
actually used, this is not reasonable and does not work as intended.
Why is the generic version not reasonable? We need a custom version
just because it can put the percpu variable in the best node. If NUMA
disabled, software can only see one node, how to optimize?

The initial aim is to use the arch specific setup_per_cpu_areas()
in any case under CONFIG_SMP, this patch can be dropped if it is
meaningless for the case of !CONFIG_NUMA and CONFIG_SMP.

Thanks,
Tiezhu