Hi David, I love your patch! Yet something to improve: [auto build test ERROR on next-20200909] [cannot apply to mmotm/master hnaz-linux-mm/master xen-tip/linux-next powerpc/next linus/master v5.9-rc4 v5.9-rc3 v5.9-rc2 v5.9-rc4] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/David-Hildenbrand/mm-memory_hotp... base: 7204eaa2c1f509066486f488c9dcb065d7484494 config: x86_64-randconfig-a016-20200909 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 0a5dc7effb191eff740e0e7ae7bd8e1f6bdb3ad9) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # install x86_64 cross compiling tool for clang build # apt-get install binutils-x86-64-linux-gnu # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): WARNING: unmet direct dependencies detected for PHY_SAMSUNG_UFS Depends on OF && (ARCH_EXYNOS || COMPILE_TEST Selected by - SCSI_UFS_EXYNOS && SCSI_LOWLEVEL && SCSI && SCSI_UFSHCD_PLATFORM && (ARCH_EXYNOS || COMPILE_TEST In file included from arch/x86/kernel/asm-offsets.c:9: In file included from include/linux/crypto.h:20: In file included from include/linux/slab.h:15: In file included from include/linux/gfp.h:6: In file included from include/linux/mmzone.h:853: >> include/linux/memory_hotplug.h:354:55: error: unknown type name 'mhp_t' extern int __add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags); ^ include/linux/memory_hotplug.h:355:53: error: unknown type name 'mhp_t' extern int add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags); ^ include/linux/memory_hotplug.h:357:11: error: unknown type name 'mhp_t' mhp_t mhp_flags); ^ include/linux/memory_hotplug.h:360:10: error: unknown type name 'mhp_t' mhp_t mhp_flags); ^ 4 errors generated. Makefile Module.symvers System.map arch block certs crypto drivers fs include init ipc kernel lib mm modules.builtin modules.builtin.modinfo modules.order net scripts security sound source tools usr virt vmlinux vmlinux.o vmlinux.symvers [scripts/Makefile.build:117: arch/x86/kernel/asm-offsets.s] Error 1 Target '__build' not remade because of errors. Makefile Module.symvers System.map arch block certs crypto drivers fs include init ipc kernel lib mm modules.builtin modules.builtin.modinfo modules.order net scripts security sound source tools usr virt vmlinux vmlinux.o vmlinux.symvers [Makefile:1196: prepare0] Error 2 Target 'prepare' not remade because of errors. make: Makefile Module.symvers System.map arch block certs crypto drivers fs include init ipc kernel lib mm modules.builtin modules.builtin.modinfo modules.order net scripts security sound source tools usr virt vmlinux vmlinux.o vmlinux.symvers [Makefile:185: __sub-make] Error 2 make: Target 'prepare' not remade because of errors. # https://github.com/0day-ci/linux/commit/d88270d1c0783a7f99f24a85692be90fd... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review David-Hildenbrand/mm-memory_hotplug-selective-merging-of-system-ram-resources/20200910-171630 git checkout d88270d1c0783a7f99f24a85692be90fd2ae0d7d vim +/mhp_t +354 include/linux/memory_hotplug.h 352 353 extern void __ref free_area_init_core_hotplug(int nid); > 354 extern int __add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags);