@@ -931,8 +931,20 @@ void __init mem_topology_setup(void)
reset_numa_cpu_lookup_table();
- for_each_present_cpu(cpu)
- numa_setup_cpu(cpu);
+ for_each_possible_cpu(cpu) {
+ /*
+ * Powerpc with CONFIG_NUMA always used to have a node 0,
+ * even if it was memoryless or cpuless. For all cpus that
+ * are possible but not present, cpu_to_node() would point
+ * to node 0. To remove a cpuless, memoryless dummy node,
+ * powerpc need to make sure all possible but not present
+ * cpu_to_node are set to a proper node.
+ */
+ if (cpu_present(cpu))
+ numa_setup_cpu(cpu);
+ else
+ set_cpu_numa_node(cpu, first_online_node);
+ }
}
void __init initmem_init(void)
A Powerpc system with multiple possible nodes and with CONFIG_NUMA enabled always used to have a node 0, even if node 0 does not any cpus or memory attached to it. As per PAPR, node affinity of a cpu is only available once its present / online. For all cpus that are possible but not present, cpu_to_node() would point to node 0. To ensure a cpuless, memoryless dummy node is not online, powerpc need to make sure all possible but not present cpu_to_node are set to a proper node. Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org Cc: Michal Hocko <mhocko@suse.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Christopher Lameter <cl@linux.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> --- Changelog v1:->v2: - Rebased to v5.7-rc3 arch/powerpc/mm/numa.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-)