Messages in this thread | | | Date | Wed, 27 Mar 2024 07:36:17 -0700 (PDT) | Subject | Re: [PATCH v3] NUMA: Early use of cpu_to_node() returns 0 instead of the correct node id | From | Palmer Dabbelt <> |
| |
On Thu, 25 Jan 2024 22:44:51 PST (-0800), shijie@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. > > Signed-off-by: Huang Shijie <shijie@os.amperecomputing.com> > --- > 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@os.amperecomputing.com/ > > 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);
Acked-by: Palmer Dabbelt <palmer@rivosinc.com> # RISC-V
I don't really understand the init/main.c stuff all that well, I'm adding Andrew as it looks like he's been merging stuff here.
| |