Re: [PATCH][V4] Add reboot_pid_ns to handle the reboot syscall

[Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>]

On Wed, 14 Dec 2011 20:17:39 +0100
Oleg Nesterov <oleg-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> wrote:

> > It would be
> > better to do
> >
> > #ifdef CONFIG_PID_NS
> > extern void pidns_handle_reboot(int cmd);
> > #else
> > static inline void pidns_handle_reboot(int cmd)
> > {
> > }
> > #endif
> 
> Can't resist.
> 
> Why the kernel always prefers to do it this way, adding the ugly
> do-nothing inlines?
> 
> Isn't it better to simply call pidns_handle_reboot(cmd) under
> CONFIG_PID_NS in sys_reboot() ?
> 
> 	#ifdef CONFIG_PID_NS
> 	if (task_active_pid_ns(current) != &init_pid_ns)
> 		return reboot_pid_ns(cmd);
> 	#endif

Imagine what the code would look like if we took all the existing empty
inline stubs and replaced them with #if/#else/#endif.