reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/daveh/devel.git/commit/?id=a820a994160883fea70750876fe26073766d831f
        git remote add daveh-devel https://git.kernel.org/pub/scm/linux/kernel/git/daveh/devel.git
        git fetch --no-tags daveh-devel shstk-vmalloc
        git checkout a820a994160883fea70750876fe26073766d831f

        # 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 arch/x86/kernel/