On Thu, 30 Jun 2022 at 14:07, Arnd Bergmann <arnd@xxxxxxxx> wrote: > > On Thu, Jun 30, 2022 at 6:32 AM Huacai Chen <chenhuacai@xxxxxxxxxxx> wrote: > > > > To avoid build error on LoongArch we should include linux/static_key.h > > in page-flags.h. > > This is an expensive change in terms of compile speed, as static_key.h has > lots of dependencies, and page-flags.h is included in a lot of places. What > it is actually needed for? > Hi, Arnd, If CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP=y, the page-flags.h relies on static keys. If we don't include static_key.h, we will get the following errors when compiling. In file included from ./include/linux/mmzone.h:22, from ./include/linux/gfp.h:6, from ./include/linux/mm.h:7, from arch/loongarch/kernel/asm-offsets.c:9: ./include/linux/page-flags.h:208:1: warning: data definition has no type or storage class 208 | DECLARE_STATIC_KEY_MAYBE(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON, | ^~~~~~~~~~~~~~~~~~~~~~~~ ./include/linux/page-flags.h:208:1: error: type defaults to 'int' in declaration of 'DECLARE_STATIC_KEY_MAYBE' [-Werror=implicit-int] ./include/linux/page-flags.h:209:26: warning: parameter names (without types) in function declaration 209 | hugetlb_optimize_vmemmap_key); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ ./include/linux/page-flags.h: In function 'hugetlb_optimize_vmemmap_enabled': ./include/linux/page-flags.h:213:16: error: implicit declaration of function 'static_branch_maybe' [-Werror=implicit-function-declaration] 213 | return static_branch_maybe(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON, | ^~~~~~~~~~~~~~~~~~~ ./include/linux/page-flags.h:213:36: error: 'CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON' undeclared (first use in this function); did you mean 'CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP'? 213 | return static_branch_maybe(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP ./include/linux/page-flags.h:213:36: note: each undeclared identifier is reported only once for each function it appears in ./include/linux/page-flags.h:214:37: error: 'hugetlb_optimize_vmemmap_key' undeclared (first use in this function); did you mean 'hugetlb_optimize_vmemmap_enabled'? 214 | &hugetlb_optimize_vmemmap_key); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ | hugetlb_optimize_vmemmap_enabled Thanks, Feiyang > Arnd >
