On Tue, Jul 5, 2022 at 2:22 PM Huacai Chen <chenhuacai@xxxxxxxxxx> wrote: > > Hi, Arnd, > > On Mon, Jul 4, 2022 at 8:18 PM Arnd Bergmann <arnd@xxxxxxxx> wrote: > > > > On Mon, Jul 4, 2022 at 1:25 PM Huacai Chen <chenhuacai@xxxxxxxxxxx> wrote: > > > To avoid the following build error on LoongArch we should include linux/ > > > static_key.h in page-flags.h. > > > > > > 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 > > > > I wonder if page_fixed_fake_head() should be moved out of line to avoid > > this, it's already nontrivial here, and that would avoid the static key > > in a central header. > I have some consideration here. I think both inline function and > static key are instruments to make things faster, in other words, > page_fixed_fake_head() is a performance critical function. If so, it > is not suitable to move it out of line. +1 The static key is an optimization when HVO is disabled. Thanks. > > Huacai > > > > Arnd > >