Hi Rafael, Thank you for the patch! Yet something to improve: [auto build test ERROR on hnaz-linux-mm/master] url: https://github.com/0day-ci/linux/commits/Rafael-Aquini/mm-slab_common-pro... base: https://github.com/hnaz/linux-mm master config: powerpc-randconfig-r004-20210318 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project fcc1ce00931751ac02498986feb37744e9ace8de) 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 powerpc cross compiling tool for clang build # apt-get install binutils-powerpc-linux-gnu # https://github.com/0day-ci/linux/commit/d6cb7528eaf0afbcb48bee452f7fa3959... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Rafael-Aquini/mm-slab_common-provide-slab_merge-option-for-IS_ENABLED-CONFIG_SLAB_MERGE_DEFAULT-builds/20210320-032434 git checkout d6cb7528eaf0afbcb48bee452f7fa395938bd559 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc 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 >>): __do_insb ^ arch/powerpc/include/asm/io.h:541:56: note: expanded from macro '__do_insb' #define __do_insb(p, b, n) readsb((PCI_IO_ADDR)_IO_BASE+(p), (b), (n)) ~~~~~~~~~~~~~~~~~~~~~^ In file included from mm/slab_common.c:11: In file included from include/linux/interrupt.h:11: In file included from include/linux/hardirq.h:10: In file included from arch/powerpc/include/asm/hardirq.h:6: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/powerpc/include/asm/io.h:604: arch/powerpc/include/asm/io-defs.h:45:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(insw, (unsigned long p, void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:9:1: note: expanded from here __do_insw ^ arch/powerpc/include/asm/io.h:542:56: note: expanded from macro '__do_insw' #define __do_insw(p, b, n) readsw((PCI_IO_ADDR)_IO_BASE+(p), (b), (n)) ~~~~~~~~~~~~~~~~~~~~~^ In file included from mm/slab_common.c:11: In file included from include/linux/interrupt.h:11: In file included from include/linux/hardirq.h:10: In file included from arch/powerpc/include/asm/hardirq.h:6: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/powerpc/include/asm/io.h:604: arch/powerpc/include/asm/io-defs.h:47:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(insl, (unsigned long p, void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:11:1: note: expanded from here __do_insl ^ arch/powerpc/include/asm/io.h:543:56: note: expanded from macro '__do_insl' #define __do_insl(p, b, n) readsl((PCI_IO_ADDR)_IO_BASE+(p), (b), (n)) ~~~~~~~~~~~~~~~~~~~~~^ In file included from mm/slab_common.c:11: In file included from include/linux/interrupt.h:11: In file included from include/linux/hardirq.h:10: In file included from arch/powerpc/include/asm/hardirq.h:6: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/powerpc/include/asm/io.h:604: arch/powerpc/include/asm/io-defs.h:49:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(outsb, (unsigned long p, const void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:13:1: note: expanded from here __do_outsb ^ arch/powerpc/include/asm/io.h:544:58: note: expanded from macro '__do_outsb' #define __do_outsb(p, b, n) writesb((PCI_IO_ADDR)_IO_BASE+(p),(b),(n)) ~~~~~~~~~~~~~~~~~~~~~^ In file included from mm/slab_common.c:11: In file included from include/linux/interrupt.h:11: In file included from include/linux/hardirq.h:10: In file included from arch/powerpc/include/asm/hardirq.h:6: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/powerpc/include/asm/io.h:604: arch/powerpc/include/asm/io-defs.h:51:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(outsw, (unsigned long p, const void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:15:1: note: expanded from here __do_outsw ^ arch/powerpc/include/asm/io.h:545:58: note: expanded from macro '__do_outsw' #define __do_outsw(p, b, n) writesw((PCI_IO_ADDR)_IO_BASE+(p),(b),(n)) ~~~~~~~~~~~~~~~~~~~~~^ In file included from mm/slab_common.c:11: In file included from include/linux/interrupt.h:11: In file included from include/linux/hardirq.h:10: In file included from arch/powerpc/include/asm/hardirq.h:6: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/powerpc/include/asm/io.h:604: arch/powerpc/include/asm/io-defs.h:53:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(outsl, (unsigned long p, const void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:17:1: note: expanded from here __do_outsl ^ arch/powerpc/include/asm/io.h:546:58: note: expanded from macro '__do_outsl' #define __do_outsl(p, b, n) writesl((PCI_IO_ADDR)_IO_BASE+(p),(b),(n)) ~~~~~~~~~~~~~~~~~~~~~^ __setup("slab_merge", setup_slab_nomerge); ^ include/linux/init.h:262:2: note: expanded from macro '__setup' __setup_param(str, fn, fn, 0) ^ include/linux/init.h:254:20: note: expanded from macro '__setup_param' static const char __setup_str_##unique_id[] __initconst \ ^ <scratch space>:124:1: note: expanded from here __setup_str_setup_slab_nomerge ^ mm/slab_common.c:83:1: note: previous definition is here __setup("slab_nomerge", setup_slab_nomerge); ^ include/linux/init.h:262:2: note: expanded from macro '__setup' __setup_param(str, fn, fn, 0) ^ include/linux/init.h:254:20: note: expanded from macro '__setup_param' static const char __setup_str_##unique_id[] __initconst \ ^ <scratch space>:119:1: note: expanded from here __setup_str_setup_slab_nomerge ^ 12 warnings and 1 error generated. vim +/__setup_str_setup_slab_nomerge +84 mm/slab_common.c 82 83 __setup("slab_nomerge", setup_slab_nomerge); 85 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org