On Wed, Mar 22, 2023 at 03:54:09PM +0800, WANG Xuerui wrote: > On 2023/3/22 15:42, Mike Rapoport wrote: > > On Tue, Mar 21, 2023 at 10:59:36AM +0800, Huacai Chen wrote: > > > Hi, all, > > > > > > On Mon, Mar 20, 2023 at 11:56 PM Kirill A. Shutemov > > > <kirill@xxxxxxxxxxxxx> wrote: > > > > > > > > On Mon, Mar 20, 2023 at 04:06:33PM +0800, kernel test robot wrote: > > > > > tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master > > > > > head: 73f2c2a7e1d2b31fdd5faa6dfa151c437a6c0a5a > > > > > commit: af8daebdbc0833b8095767ccef7ddce55e9fdf32 [3778/4413] mm, treewide: redefine MAX_ORDER sanely > > > > > config: loongarch-buildonly-randconfig-r003-20230320 (https://download.01.org/0day-ci/archive/20230320/202303201615.Qfu18nWV-lkp@xxxxxxxxx/config) > > > > > compiler: loongarch64-linux-gcc (GCC) 12.1.0 > > > > > 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 > > > > > # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=af8daebdbc0833b8095767ccef7ddce55e9fdf32 > > > > > git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git > > > > > git fetch --no-tags linux-next master > > > > > git checkout af8daebdbc0833b8095767ccef7ddce55e9fdf32 > > > > > # save the config file > > > > > mkdir build_dir && cp config build_dir/.config > > > > > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=loongarch olddefconfig > > > > > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=loongarch prepare > > > > > > > > > > If you fix the issue, kindly add following tag where applicable > > > > > | Reported-by: kernel test robot <lkp@xxxxxxxxx> > > > > > | Link: https://lore.kernel.org/oe-kbuild-all/202303201615.Qfu18nWV-lkp@xxxxxxxxx/ > > > > > > > > > > All errors (new ones prefixed by >>): > > > > > > > > > > In file included from include/linux/gfp.h:7, > > > > > from include/linux/mm.h:7, > > > > > from arch/loongarch/kernel/asm-offsets.c:9: > > > > > > > include/linux/mmzone.h:1749:2: error: #error Allocator MAX_ORDER exceeds SECTION_SIZE > > > > > 1749 | #error Allocator MAX_ORDER exceeds SECTION_SIZE > > > > > | ^~~~~ > > > > > > > > +Loongarch folks. > > > LoongArch defines SECTION_SIZE_BITS as 29, so I think the upper limit > > > of ARCH_FORCE_MAX_ORDER should not be 63, MIPS is similar. > > The ranges MIPS add LoongArch define for ARCH_FORCE_MAX_ORDER are insane. > > I'm going to drop them and leave ARCH_FORCE_MAX_ORDER an int with sane > > defaults. > > > > As for this splat, in the .config above ARCH_FORCE_MAX_ORDER=14 and > > PAGE_SIZE=64k, so we end up with MAX_ORDER + PAGE_SHIFT being 30, that's > > larger than SECTION_SIZE. > > > > AFAIK randconfig does not randomize integers, so it's unclear to me how > > ARCH_FORCE_MAX_ORDER got to 14. > > > > As far as I can see, arch/loongarch/Kconfig has the following lines: > > > config ARCH_FORCE_MAX_ORDER > > int "Maximum zone order" > > range 14 64 if PAGE_SIZE_64KB > > default "14" if PAGE_SIZE_64KB > > range 12 64 if PAGE_SIZE_16KB > > default "12" if PAGE_SIZE_16KB > > range 11 64 > > default "11" > > So the value 14 is because PAGE_SIZE_64KB is being set, which I confirmed to > be the case with this particular run. And I believe the stanza is inherited > from arch/mips. With Kirill's patch the range became '13 63', so I don't see why randconfig would set ARCH_FORCE_MAX_ORDER to 14. > Looking at other arches it seems a much smaller upper limit would be > desirable. Even the lower limit of 14 could be lowered, e.g. arch/powerpc > has "range 8 9 if PPC64 && PPC_64K_PAGES". Is that okay? I don't think architectures should mess with MAX_ORDER unless strictly necessary. Having an integer config symbol with sensible defaults is enough to ensure that MAX_ORDER can fit a PMD page. I really doubt anyone should ever override that default in their kernel builds. > -- > WANG "xen0n" Xuerui > > Linux/LoongArch mailing list: https://lore.kernel.org/loongarch/ > -- Sincerely yours, Mike.
