On Fri, 19 May 2017, Christoph Hellwig wrote:
> - /* Stabilize the cpumasks */
> - get_online_cpus();
How is that protected against physical CPU hotplug? Physical CPU hotplug
manipulates the present mask.
> - nodes = get_nodes_in_cpumask(cpu_online_mask, &nodemsk);
> + nodes = get_nodes_in_cpumask(cpu_present_mask, &nodemsk);
> +static int __init irq_build_cpumap(void)
> +{
> + int node, cpu;
> +
> + for (node = 0; node < nr_node_ids; node++) {
> + if (!zalloc_cpumask_var(&node_to_present_cpumask[node],
> + GFP_KERNEL))
> + panic("can't allocate early memory\n");
> + }
>
> - return min(cpus, vecs) + resv;
> + for_each_present_cpu(cpu) {
> + node = cpu_to_node(cpu);
> + cpumask_set_cpu(cpu, node_to_present_cpumask[node]);
> + }
This mask needs updating on physical hotplug as well.
Thanks,
tglx
