Commit d519aab0 authored Jul 31, 2018 by Martin Schwidefsky Committed by Greg Kroah-Hartman Sep 05, 2018

s390/numa: move initial setup of node_to_cpumask_map



commit fb7d7518b0d65955f91c7b875c36eae7694c69bd upstream.

The numa_init_early initcall sets the node_to_cpumask_map[0] to the
full cpu_possible_mask. Unfortunately this early_initcall is too late,
the NUMA setup for numa=emu is done even earlier. The order of calls
is numa_setup() -> emu_update_cpu_topology(), then the early_initcalls(),
followed by sched_init_domains().

Starting with git commit 051f3ca02e46432c0965e8948f00c07d8a2f09c0
"sched/topology: Introduce NUMA identity node sched domain"
the incorrect node_to_cpumask_map[0] really screws up the domain
setup and the kernel panics with the follow oops:

Cc: <stable@vger.kernel.org> # v4.15+
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent b9f66a2b

arch/s390/numa/numa.c

+2 −14

Original line number	Diff line number	Diff line
		@@ -133,26 +133,14 @@ void __init numa_setup(void)
		{
		pr_info("NUMA mode: %s\n", mode->name);
		nodes_clear(node_possible_map);
		/* Initially attach all possible CPUs to node 0. */
		cpumask_copy(&node_to_cpumask_map[0], cpu_possible_mask);
		if (mode->setup)
		mode->setup();
		numa_setup_memory();
		memblock_dump_all();
		}

		/*
		* numa_init_early() - Initialization initcall
		*
		* This runs when only one CPU is online and before the first
		* topology update is called for by the scheduler.
		*/
		static int __init numa_init_early(void)
		{
		/* Attach all possible CPUs to node 0 for now. */
		cpumask_copy(&node_to_cpumask_map[0], cpu_possible_mask);
		return 0;
		}
		early_initcall(numa_init_early);

		/*
		* numa_init_late() - Initialization initcall
		*