diff --git a/libc/kernel/common/asm-generic/cputime.h b/libc/kernel/common/asm-generic/cputime.h
index 0486b87..dbc7859 100644
--- a/libc/kernel/common/asm-generic/cputime.h
+++ b/libc/kernel/common/asm-generic/cputime.h
@@ -7,54 +7,58 @@
  ***   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 _ASM_GENERIC_CPUTIME_H
 #define _ASM_GENERIC_CPUTIME_H
-
 #include <linux/time.h>
 #include <linux/jiffies.h>
-
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 typedef unsigned long cputime_t;
-
 #define cputime_zero (0UL)
 #define cputime_max ((~0UL >> 1) - 1)
 #define cputime_add(__a, __b) ((__a) + (__b))
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define cputime_sub(__a, __b) ((__a) - (__b))
 #define cputime_div(__a, __n) ((__a) / (__n))
 #define cputime_halve(__a) ((__a) >> 1)
 #define cputime_eq(__a, __b) ((__a) == (__b))
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define cputime_gt(__a, __b) ((__a) > (__b))
 #define cputime_ge(__a, __b) ((__a) >= (__b))
 #define cputime_lt(__a, __b) ((__a) < (__b))
 #define cputime_le(__a, __b) ((__a) <= (__b))
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define cputime_to_jiffies(__ct) (__ct)
 #define jiffies_to_cputime(__hz) (__hz)
-
 typedef u64 cputime64_t;
-
 #define cputime64_zero (0ULL)
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define cputime64_add(__a, __b) ((__a) + (__b))
 #define cputime64_sub(__a, __b) ((__a) - (__b))
 #define cputime64_to_jiffies64(__ct) (__ct)
 #define jiffies64_to_cputime64(__jif) (__jif)
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define cputime_to_cputime64(__ct) ((u64) __ct)
-
 #define cputime_to_msecs(__ct) jiffies_to_msecs(__ct)
 #define msecs_to_cputime(__msecs) msecs_to_jiffies(__msecs)
-
 #define cputime_to_secs(jif) ((jif) / HZ)
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define secs_to_cputime(sec) ((sec) * HZ)
-
 #define timespec_to_cputime(__val) timespec_to_jiffies(__val)
 #define cputime_to_timespec(__ct,__val) jiffies_to_timespec(__ct,__val)
-
 #define timeval_to_cputime(__val) timeval_to_jiffies(__val)
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define cputime_to_timeval(__ct,__val) jiffies_to_timeval(__ct,__val)
-
 #define cputime_to_clock_t(__ct) jiffies_to_clock_t(__ct)
 #define clock_t_to_cputime(__x) clock_t_to_jiffies(__x)
-
 #define cputime64_to_clock_t(__ct) jiffies_64_to_clock_t(__ct)
-
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #endif