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. Signed-off-by: Huang Shijie <shijie@xxxxxxxxxxxxxxxxxxxxxx> --- v2 --> v3: Do not change the cpu_to_node to function pointer. Introduce early_numa_node_init() which initialize the numa_node at an early stage. v2: https://lore.kernel.org/all/20240123045843.75969-1-shijie@xxxxxxxxxxxxxxxxxxxxxx/ v1 --> v2: In order to fix the x86 compiling error, move the cpu_to_node() from driver/base/arch_numa.c to driver/base/node.c. v1: http://lists.infradead.org/pipermail/linux-arm-kernel/2024-January/896160.html An old different title patch: http://lists.infradead.org/pipermail/linux-arm-kernel/2024-January/895963.html --- init/main.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/init/main.c b/init/main.c index e24b0780fdff..39efe5ed58a0 100644 --- a/init/main.c +++ b/init/main.c @@ -870,6 +870,19 @@ static void __init print_unknown_bootoptions(void) memblock_free(unknown_options, len); } +static void __init early_numa_node_init(void) +{ +#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID +#ifndef cpu_to_node + int cpu; + + /* The early_cpu_to_node() should be ready here. */ + for_each_possible_cpu(cpu) + set_cpu_numa_node(cpu, early_cpu_to_node(cpu)); +#endif +#endif +} + asmlinkage __visible __init __no_sanitize_address __noreturn __no_stack_protector void start_kernel(void) { @@ -900,6 +913,7 @@ void start_kernel(void) setup_nr_cpu_ids(); setup_per_cpu_areas(); smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */ + early_numa_node_init(); boot_cpu_hotplug_init(); pr_notice("Kernel command line: %s\n", saved_command_line); -- 2.40.1
