On Sat, 2 Feb 2019 00:14:13 +0800 kbuild test robot <lkp@xxxxxxxxx> wrote: > tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master > head: 9fe36dd579c794ae5f1c236293c55fb6847e9654 > commit: a3402cb621c1b3908600d3f364e991a6c5a8c06e [5141/5361] mm/hmm: improve driver API to work and wait over a range > config: x86_64-randconfig-b0-02012138 (attached as .config) > compiler: gcc-8 (Debian 8.2.0-14) 8.2.0 > reproduce: > git checkout a3402cb621c1b3908600d3f364e991a6c5a8c06e > # save the attached .config to linux build tree > make ARCH=x86_64 > > All errors (new ones prefixed by >>): > > In file included from kernel/memremap.c:14: > >> include/linux/hmm.h:102:22: error: field 'mmu_notifier' has incomplete type > struct mmu_notifier mmu_notifier; I can't reproduce this with that .config. hmm.h includes mmu_notifier.h so I can't eyeball why this would happen.