reproduce (this is a W=1 build):
        git remote add lwn git://git.lwn.net/linux.git
        git fetch --no-tags lwn docs-next
        git checkout 5f88f44d8427a97347afda3a6114aed0df472a0b

        # 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 drivers/cpufreq/