<div dir="ltr"><div class="gmail_extra"><br><div class="gmail_quote">On 28 July 2015 at 03:00, <span dir="ltr"><<a href="mailto:rongqing.li@windriver.com" target="_blank">rongqing.li@windriver.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div id=":3ky" class="a3s" style="overflow:hidden">+<a href="http://config.mk" rel="noreferrer" target="_blank">config.mk</a> will be included only if auto.conf is newer than .config<br>
+but in some system, the HPET is not enabled, the smallest unit of<br>
+time is second, and can not decise which file is newer, even if<br>
+the correct dependency has been created.<br>
+<br>
+The below shows unit of time:<br>
+<br>
+under SUSE Linux Enterprise Desktop 11 SP2 (i586):<br>
+ $ls --full-time include/config/auto.conf .config<br>
+ 2015-07-27 03:46:20.000000000 -0400 .config<br>
+ 2015-07-27 03:46:20.000000000 -0400 include/config/auto.conf<br>
+ $<br>
+<br>
+under Ubuntu 14.04 LTS:<br>
+ $ ls --full-time include/config/auto.conf .config<br>
+ 2015-07-27 13:40:14.008703027 +0800 .config<br>
+ 2015-07-27 13:40:15.020703054 +0800 include/config/auto.conf<br>
+ $<br>
+<br>
+The rule of including <a href="http://config.mk" rel="noreferrer" target="_blank">config.mk</a> in Makefile as below<br>
+ autoconf_is_current := $(if $(wildcard $(KCONFIG_CONFIG)),$(shell find . \<br>
+ -path ./include/config/auto.conf -newer $(KCONFIG_CONFIG)))<br>
+ ifneq ($(autoconf_is_current),)<br>
+ include $(srctree)/<a href="http://config.mk" rel="noreferrer" target="_blank">config.mk</a><br>
+ include $(srctree)/arch/$(ARCH)/Makefile<br>
+ endif<br>
+<br>
+The compilation will be failed if <a href="http://config.mk" rel="noreferrer" target="_blank">config.mk</a> is not included<br>
+so delay 1 second to create auto.conf after creating of .config</div></blockquote></div><br>Adding a sleep seems pretty ugly, wouldn't a neater fix be to change the logic so that instead of the test being "is newer" you use "is not older", to handle identical timestamps as being current.</div><div class="gmail_extra"><br></div><div class="gmail_extra">Ross</div></div>