On Fri, 26 Jan 2024 14:44:51 +0800 Huang Shijie <shi...@os.amperecomputing.com> wrote:
> During the kernel booting, the generic cpu_to_node() is called too early in > arm64, powerpc and riscv when CONFIG_NUMA is enabled. > > There are at least four places in the common code where > the generic cpu_to_node() is called before it is initialized: > 1.) early_trace_init() in kernel/trace/trace.c > 2.) sched_init() in kernel/sched/core.c > 3.) init_sched_fair_class() in kernel/sched/fair.c > 4.) workqueue_init_early() in kernel/workqueue.c > > In order to fix the bug, the patch introduces early_numa_node_init() > which is called after smp_prepare_boot_cpu() in start_kernel. > early_numa_node_init will initialize the "numa_node" as soon as > the early_cpu_to_node() is ready, before the cpu_to_node() is called > at the first time. What are the userspace-visible runtime effects of this bug?
