[PATCH v3 2/3] powerpc/numa: Prefer node id queried from vphn

Srikar Dronamraju
2020-05-01T03:12:03Z

Node id queried from the static device tree may not
be correct. For example: it may always show 0 on a shared processor.
Hence prefer the node id queried from vphn and fallback on the device tree
based node id if vphn query fails.

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>
Cc: Gautham R Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
---
Changelog v2:->v3:
- Resolved comments from Gautham.
Link v2: https://lore.kernel.org/linuxppc-dev/20200428093836.27190-1-srikar@linux.vnet.ibm.com/t/#u

Changelog v1:->v2:
- Rebased to v5.7-rc3

arch/powerpc/mm/numa.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index b3615b7fdbdf..79c74a2753c1 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -719,21 +719,22 @@ static int __init parse_numa_properties(void)
*/
for_each_present_cpu(i) {
struct device_node *cpu;
- int nid;
-
- cpu = of_get_cpu_node(i, NULL);
- BUG_ON(!cpu);
- nid = of_node_to_nid_single(cpu);
- of_node_put(cpu);
+ int nid = vphn_get_nid(i);

/*
* Don't fall back to default_nid yet -- we will plug
* cpus into nodes once the memory scan has discovered
* the topology.
*/
- if (nid < 0)
- continue;
- node_set_online(nid);
+ if (nid == NUMA_NO_NODE) {
+ cpu = of_get_cpu_node(i, NULL);
+ BUG_ON(!cpu);
+ nid = of_node_to_nid_single(cpu);
+ of_node_put(cpu);
+ }
+
+ if (likely(nid > 0))
+ node_set_online(nid);
}

get_n_mem_cells(&n_mem_addr_cells, &n_mem_size_cells);
--
2.20.1