Re: [PATCH] x86_64: fix build without HOTPLUG_CPU (was Re: 2.6.19-rc6-mm1)

Jiri Kosina
2006-11-23T15:38:23Z

On Thu, 23 Nov 2006, Andi Kleen wrote:

> > Well, is it really? 6b3d1a95ba714bfb1cc81362f7f3e01b7654b4f3 adds the
> > ifdef around the cpu_vsyscall_notifier() declaration, but later it's
> > passed as parameter to hotcpu_notifier() unconditionally. This is fixed by
> > the patch I sent.
> hotcpu_notifier is a macro that expands to nothing for !CONFIG_HOTPLUG_CPU

Now I see where does the confusion come from. 2.6.19-rc6-mm1 has
hotplug-cpu-clean-up-hotcpu_notifier-use.patch from Ingo (CC added), which
does this, among other things:

-#define hotcpu_notifier(fn, pri) do { } while (0)
-#define register_hotcpu_notifier(nb) do { } while (0)
-#define unregister_hotcpu_notifier(nb) do { } while (0)
+#define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0)
+#define register_hotcpu_notifier(nb) do { (void)(nb); } while (0)
+#define unregister_hotcpu_notifier(nb) do { (void)(nb); } while (0)

--
Jiri Kosina
SUSE Labs