[PATCH v2] powerpc: Fix warning reported by verify_cpu_node_mapping()

Li Zhong zhong at linux.vnet.ibm.com
Mon Aug 25 17:22:35 EST 2014


With commit 2fabf084b, during boottime, cpu_numa_callback() is called
earlier(before their online) for each cpu, and verify_cpu_node_mapping()
uses cpu_to_node() to check whether siblings are in the same node. 

It skips the checking for siblings that are not online yet. So the only
check done here is for the bootcpu, which is online at that time. But
the per-cpu numa_node cpu_to_node() uses hasn't been set up yet (which
will be set up in smp_prepare_cpus()).

So I saw something like following reported:
[    0.000000] CPU thread siblings 1/2/3 and 0 don't belong to the same
node!

As we don't actually do the checking during this early stage, so maybe
we could directly call numa_setup_cpu() in do_init_bootmem().

Also, as Nish suggested, here it's better to use present cpu mask
instead of possible mask to avoid warning in numa_setup_cpu().

Signed-off-by: Li Zhong <zhong at linux.vnet.ibm.com>
---
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index d7737a5..3a9061e 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -1127,9 +1127,8 @@ void __init do_init_bootmem(void)
 	 * even before we online them, so that we can use cpu_to_{node,mem}
 	 * early in boot, cf. smp_prepare_cpus().
 	 */
-	for_each_possible_cpu(cpu) {
-		cpu_numa_callback(&ppc64_numa_nb, CPU_UP_PREPARE,
-				  (void *)(unsigned long)cpu);
+	for_each_present_cpu(cpu) {
+		numa_setup_cpu((unsigned long)cpu);
 	}
 }
 




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