x86: add debug of invalid per_cpu map accesses
Provide a means to trap usages of per_cpu map variables before
they are setup. Define CONFIG_DEBUG_PER_CPU_MAPS to activate.
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/include/asm-x86/topology.h b/include/asm-x86/topology.h
index 040374f..f1e1232 100644
--- a/include/asm-x86/topology.h
+++ b/include/asm-x86/topology.h
@@ -66,6 +66,13 @@
static inline int cpu_to_node(int cpu)
{
+#ifdef CONFIG_DEBUG_PER_CPU_MAPS
+ if(x86_cpu_to_node_map_early_ptr) {
+ printk("KERN_NOTICE cpu_to_node(%d): usage too early!\n",
+ (int)cpu);
+ BUG();
+ }
+#endif
if(per_cpu_offset(cpu))
return per_cpu(x86_cpu_to_node_map, cpu);
else