Hi Yunhui, Thank you for the patch! Yet something to improve: [auto build test ERROR on bpf-next/master] [also build test ERROR on bpf/master linus/master v6.0-rc3 next-20220901] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Yunhui-Cui/bpf-added-the-account-of-BPF-running-time/20220902-181437 base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master config: um-x86_64_defconfig (https://download.01.org/0day-ci/archive/20220903/202209030333.Goj9I0Pe-lkp@xxxxxxxxx/config) compiler: gcc-11 (Debian 11.3.0-5) 11.3.0 reproduce (this is a W=1 build): # https://github.com/intel-lab-lkp/linux/commit/e31420772f2a63d6bc561211b8ef0331d41b2123 git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Yunhui-Cui/bpf-added-the-account-of-BPF-running-time/20220902-181437 git checkout e31420772f2a63d6bc561211b8ef0331d41b2123 # save the config file mkdir build_dir && cp config build_dir/.config make W=1 O=build_dir ARCH=um SUBARCH=x86_64 SHELL=/bin/bash If you fix the issue, kindly add following tag where applicable Reported-by: kernel test robot <lkp@xxxxxxxxx> All errors (new ones prefixed by >>): /usr/bin/ld: warning: arch/x86/um/vdso/vdso.o: missing .note.GNU-stack section implies executable stack /usr/bin/ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker /usr/bin/ld: warning: .tmp_vmlinux.kallsyms1 has a LOAD segment with RWX permissions /usr/bin/ld: kernel/seccomp.o: in function `seccomp_run_filters': seccomp.c:(.text+0xaa7): undefined reference to `bpftime' /usr/bin/ld: fs/proc/stat.o: in function `show_stat': stat.c:(.text+0x124): undefined reference to `bpftime' /usr/bin/ld: stat.c:(.text+0x332): undefined reference to `bpftime' /usr/bin/ld: net/core/flow_dissector.o: in function `bpf_flow_dissect': >> flow_dissector.c:(.text+0x9f5): undefined reference to `bpftime' /usr/bin/ld: net/core/dev.o: in function `bpf_prog_run_generic_xdp': >> dev.c:(.text+0x8c43): undefined reference to `bpftime' /usr/bin/ld: net/core/ptp_classifier.o:ptp_classifier.c:(.text+0xf8): more undefined references to `bpftime' follow collect2: error: ld returned 1 exit status -- 0-DAY CI Kernel Test Service https://01.org/lkp