Re: [PATCH 08/46] kernel: MOve prototype declaration to header file include/linux/perf_event.h

Peter Zijlstra
2014-02-27T11:54:53Z

On Thu, Feb 27, 2014 at 05:02:48PM +0530, Rashika Kheria wrote:
> Add prototype declaration of function to header file
> include/linux/perf_event.h because it is used by more than one file.
>
> This eliminates the following warning in kernel/events/core.c:
> kernel/events/core.c:3743:13: warning: no previous prototype for ‘arch_perf_update_userpage’ [-Wmissing-prototypes]

# git grep arch_perf_update_userpage
arch/x86/kernel/cpu/perf_event.c:void arch_perf_update_userpage(struct perf_event_mmap_page *userpg, u64 now)
kernel/events/core.c:void __weak arch_perf_update_userpage(struct perf_event_mmap_page *userpg, u64 now)
kernel/events/core.c: arch_perf_update_userpage(userpg, now);

There's two definitions; one weak, and one usage site.

What gives?