On Fri, Nov 02, 2018 at 04:54:25PM +0100, Arnd Bergmann wrote: > On 11/2/18, Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> wrote: > > On Thu, Nov 1, 2018 at 11:32 PM Changbin Du <changbin.du@xxxxxxxxx> wrote: > >> On Thu, Nov 01, 2018 at 12:32:48PM +0900, Masahiro Yamada wrote: > > > > How about clang? > > > > For clang, -Og might be equivalent to -O1 at this moment, but I am not > > sure. > > > > In my understanding, Clang does not inline functions marked with 'static > > inline' > > for -Og (or -O1) optimization level. > > > > Theoretically, 'inline' keyword is a just hint for the compiler, after all. > > I think this means that we cannot build the kernel in that configuration, > at least with CONFIG_OPTIMIZE_INLINING=y. Without that option, > every 'inline' becomes 'always_inline'. > > Arnd I have verified the new configuration with GCC. CONFIG_OPTIMIZE_INLINING is a whole different thing and I dont think it is so aggressive. Because many of kernel functions marked as 'inline' must be inlined. Otherwise the kernel cannot be compiled at all with CONFIG_OPTIMIZE_INLINING=y. If you wanna to try, just remove the 'inline' keyword from some kernel functions to see what happens. -- Thanks, Changbin Du
