[PATCH 4/6] x86/numa: concentrate the code of setting cpu to node map

From: Pingfan Liu
Date: Sun Feb 24 2019 - 07:35:02 EST


Both numa_init_array() and init_cpu_to_node() aim at setting up the cpu to
node map, so combining them. And the coming patch will set up node to
cpumask map in the combined function.

Signed-off-by: Pingfan Liu <kernelfans@xxxxxxxxx>
CC: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CC: Ingo Molnar <mingo@xxxxxxxxxx>
CC: Borislav Petkov <bp@xxxxxxxxx>
CC: "H. Peter Anvin" <hpa@xxxxxxxxx>
CC: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
CC: Vlastimil Babka <vbabka@xxxxxxx>
CC: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
CC: Mel Gorman <mgorman@xxxxxxx>
CC: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
CC: Andy Lutomirski <luto@xxxxxxxxxx>
CC: Andi Kleen <ak@xxxxxxxxxxxxxxx>
CC: Petr Tesarik <ptesarik@xxxxxxx>
CC: Michal Hocko <mhocko@xxxxxxxx>
CC: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
CC: Jonathan Corbet <corbet@xxxxxxx>
CC: Nicholas Piggin <npiggin@xxxxxxxxx>
CC: Daniel Vacek <neelx@xxxxxxxxxx>
CC: linux-kernel@xxxxxxxxxxxxxxx
---
arch/x86/mm/numa.c | 39 +++++++++++++--------------------------
1 file changed, 13 insertions(+), 26 deletions(-)

diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
index bfe6732..c8dd7af 100644
--- a/arch/x86/mm/numa.c
+++ b/arch/x86/mm/numa.c
@@ -599,30 +599,6 @@ static int __init numa_register_memblks(struct numa_meminfo *mi)
return 0;
}

-#ifdef CONFIG_NUMA
-/*
- * There are unfortunately some poorly designed mainboards around that
- * only connect memory to a single CPU. This breaks the 1:1 cpu->node
- * mapping. To avoid this fill in the mapping for all possible CPUs,
- * as the number of CPUs is not known yet. We round robin the existing
- * nodes.
- */
-static void __init numa_init_array(void)
-{
- int rr, i;
-
- rr = first_node(node_online_map);
- for (i = 0; i < nr_cpu_ids; i++) {
- if (early_cpu_to_node(i) != NUMA_NO_NODE)
- continue;
- numa_set_node(i, rr);
- rr = next_node_in(rr, node_online_map);
- }
-}
-#else
-static void __init numa_init_array(void) {}
-#endif
-
static int __init numa_init(int (*init_func)(void))
{
int i;
@@ -675,7 +651,6 @@ static int __init numa_init(int (*init_func)(void))
if (!node_online(nid))
numa_clear_node(i);
}
- numa_init_array();

return 0;
}
@@ -758,14 +733,26 @@ void __init init_cpu_to_node(void)
{
int cpu;
u16 *cpu_to_apicid = early_per_cpu_ptr(x86_cpu_to_apicid);
+ int rr;

BUG_ON(cpu_to_apicid == NULL);
+ rr = first_node(node_online_map);

for_each_possible_cpu(cpu) {
int node = numa_cpu_node(cpu);

- if (node == NUMA_NO_NODE)
+ /*
+ * There are unfortunately some poorly designed mainboards
+ * around that only connect memory to a single CPU. This
+ * breaks the 1:1 cpu->node mapping. To avoid this fill in
+ * the mapping for all possible CPUs, as the number of CPUs
+ * is not known yet. We round robin the existing nodes.
+ */
+ if (node == NUMA_NO_NODE) {
+ numa_set_node(cpu, rr);
+ rr = next_node_in(rr, node_online_map);
continue;
+ }

if (!node_online(node))
init_memory_less_node(node);
--
2.7.4