reproduce (this is a W=1 build): # https://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git/commit/?id=637a4f5485c20fbeb03d920745ae345b81406600 git remote add jolsa-perf https://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git git fetch --no-tags jolsa-perf bpf/optimized_usdt_1 git checkout 637a4f5485c20fbeb03d920745ae345b81406600 # save the config file mkdir build_dir && cp config build_dir/.config make W=1 O=build_dir ARCH=i386 olddefconfig make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash kernel/