Greeting, FYI, we noticed the following commit (built with gcc-9): commit: 394b6e92389887aaf0ef8a2a70ef295b045c748b ("[PATCH] libbpf: add support for canceling cached_cons advance") url: https://github.com/0day-ci/linux/commits/Li-RongQing/libbpf-add-support-f... base: https://git.kernel.org/cgit/linux/kernel/git/bpf/bpf-next.git master in testcase: perf-sanity-tests version: perf-x86_64-eccc87672492-1_20201111 with following parameters: perf_compiler: gcc ucode: 0xe2 on test machine: 4 threads Intel(R) Core(TM) i5-6500 CPU @ 3.20GHz with 32G memory caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): If you fix the issue, kindly add following tag Reported-by: kernel test robot <oliver.sang(a)intel.com&gt; In file included from xsk.c:35: xsk.h: In function ▒~@~Xxsk_ring_cons__cancel▒~@~Y: xsk.h:159:2: error: ▒~@~Xrx▒~@~Y undeclared (first use in this function) rx->cached_cons -= nb; ^~ xsk.h:159:2: note: each undeclared identifier is reported only once for each function it appears in make[4]: *** [/usr/src/perf_selftests-x86_64-rhel-8.3-394b6e92389887aaf0ef8a2a70ef295b045c748b/tools/build/Makefile.build:97: staticobjs/xsk.o] Error 1 make[4]: *** Waiting for unfinished jobs.... To reproduce: git clone https://github.com/intel/lkp-tests.git cd lkp-tests bin/lkp install job.yaml # job file is attached in this email bin/lkp run job.yaml Thanks, Oliver Sang