Hi Huang, It's probably a bug fix that unveils the link errors. tree: yhuang/random-r0.1i head: 96efac420c3a75d62cf4ff43184d4dbd0ce94b55 commit: 96efac420c3a75d62cf4ff43184d4dbd0ce94b55 [42/42] adjust promote check count config: powerpc-defconfig (attached as .config) compiler: powerpc64-linux-gcc (GCC) 7.4.0 reproduce: wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross git checkout 96efac420c3a75d62cf4ff43184d4dbd0ce94b55 # save the attached .config to linux build tree GCC_VERSION=7.4.0 make.cross ARCH=powerpc If you fix the issue, kindly add following tag Reported-by: kbuild test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): powerpc64-linux-ld: warning: orphan section `.gnu.hash' from `linker stubs' being placed in section `.gnu.hash'. mm/migrate.o: In function `.move_to_new_page': migrate.c:(.text+0x35dc): undefined reference to `.inc_hmem_state' drivers/base/node.o: In function `.random_migrate_threshold_max_ms_store': node.c:(.text+0x3a4): undefined reference to `.node_random_migrate_stop' node.c:(.text+0x434): undefined reference to `.node_random_migrate_start' drivers/base/node.o: In function `.random_migrate_period_ms_store': node.c:(.text+0x5e0): undefined reference to `.node_random_migrate_stop' node.c:(.text+0x6a8): undefined reference to `.node_random_migrate_stop' node.c:(.text+0x6e8): undefined reference to `.node_random_migrate_start' drivers/base/node.o: In function `.random_migrate_mb_store': node.c:(.text+0x8b0): undefined reference to `.node_random_migrate_stop' node.c:(.text+0x8d4): undefined reference to `.node_random_migrate_start' node.c:(.text+0x96c): undefined reference to `.node_random_migrate_pages' --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation