diff --git a/libc/kernel/common/linux/smp.h b/libc/kernel/common/linux/smp.h
index ab4982d..615f32a 100644
--- a/libc/kernel/common/linux/smp.h
+++ b/libc/kernel/common/linux/smp.h
@@ -7,20 +7,28 @@
  ***   structures, and macros generated from the original header, and thus,
  ***   contains no copyrightable information.
  ***
+ ***   To edit the content of this header, modify the corresponding
+ ***   source file (e.g. under external/kernel-headers/original/) then
+ ***   run bionic/libc/kernel/tools/update_all.py
+ ***
+ ***   Any manual change here will be lost the next time this script will
+ ***   be run. You've been warned!
+ ***
  ****************************************************************************
  ****************************************************************************/
 #ifndef __LINUX_SMP_H
 #define __LINUX_SMP_H
-
 #define raw_smp_processor_id() 0
 #define hard_smp_processor_id() 0
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define smp_call_function(func,info,retry,wait) (up_smp_call_function())
 #define on_each_cpu(func,info,retry,wait)   ({   local_irq_disable();   func(info);   local_irq_enable();   0;   })
 #define num_booting_cpus() 1
 #define smp_prepare_boot_cpu() do {} while (0)
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define smp_processor_id() raw_smp_processor_id()
 #define get_cpu() ({ preempt_disable(); smp_processor_id(); })
 #define put_cpu() preempt_enable()
 #define put_cpu_no_resched() preempt_enable_no_resched()
-
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #endif