On Wed, 26 Sep 2012 18:20:44 -0500 Daniel Santos <[email protected]> wrote:
> I've noticed that there's a lot of misperception about the meaning of > the __always_inline, or more specifically, > __attribute__((always_inline)), which does not actually cause the > function to always be inlined. Rather, it *allows* gcc to inline the > function, even when compiling without optimizations. Here is the > description of the attribute from gcc's docs > (http://gcc.gnu.org/onlinedocs/gcc-4.7.2/gcc/Function-Attributes.html) > > always_inline > Generally, functions are not inlined unless optimization is specified. > For functions declared inline, this attribute inlines the function even > if no optimization level was specified. > > This would even appear to imply that such functions aren't even marked > as "inline" (something I wasn't aware of until today). The only > mechanism I'm currently aware of to force gcc to inline a function is > the flatten attribute (see https://lkml.org/lkml/2012/9/25/643) which > works backwards, you declare it on the calling function, and it forces > gcc to inline all functions (marked as inline) that it calls. As I mentioned in the other thread, the __always_inline's in fs/namei.c (at least) are doing exactly what we want them to do, so some more investigation is needed here? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
