Hi Xiaozhou, Couple of comments.
On Sun, Dec 9, 2018 at 4:27 AM Xiaozhou Liu <liuxiaoz...@bytedance.com> wrote: > > v2: update commit message. This line should go below the "---", since it shouldn't be part of the commit message. > +#ifdef __KERNEL__ > + > #ifdef CONFIG_ENABLE_MUST_CHECK > #define __must_check __attribute__((__warn_unused_result__)) > #else > @@ -215,4 +217,6 @@ struct ftrace_likely_data { > */ > #define noinline_for_stack noinline > > +#endif /* __KERNEL */ I wonder if we can/should simply move them into the __KERNEL__ && !__ASSEMBLY__ block that is above, instead. It would be simpler to read, and there aren't apparently dependencies to those outside it that go after the block. I took a look at where the macros were at each "step", and, on one hand, compiler-gcc.h was (and is) included entirely inside it, which is from where most of the macros come originally from. On the other hand, not all do: __must_check (the generic version, not the one in -gcc.h) and noinline_for_stack were defined in __KERNEL__ (only) before commit 815f0ddb346c ("include/linux/compiler*.h: make compiler-*.h mutually exclusive"). But anyway using those two in assembly does not make sense, right? What do you think? Greg/Linus, are you going to pick this (or a v3) directly? If not, I can pick it up in compiler-attributes tree linux-next. PS: In addition (related to this but not for this patch), we should review whether other macros that are currently outside should be there or simply pushed back into __KERNEL__ (and possibly __ASSEMBLY__). For instance, __latent_entropy (the generic one) is outside, but it is only defined in compiler-gcc.h, so the generic one should be inside the __KERNEL__ && !__ASSEMBLY__ block, no? Cheers, Miguel