On Mon, Dec 23, 2019 at 6:31 AM Christophe Leroy <christophe.le...@c-s.fr> wrote: > > do_hres() is called from several places, so GCC doesn't inline > it at first. > > do_hres() takes a struct __kernel_timespec * parameter for > passing the result. In the 32 bits case, this parameter corresponds > to a local var in the caller. In order to provide a pointer > to this structure, the caller has to put it in its stack and > do_hres() has to write the result in the stack. This is suboptimal, > especially on RISC processor like powerpc. > > By making GCC inline the function, the struct __kernel_timespec > remains a local var using registers, avoiding the need to write and > read stack. > > The improvement is significant on powerpc.
I'm okay with it, mainly because I don't expect many workloads to have more than one copy of the code hot at the same time.
