On 06/23/2014 09:35 PM, Benjamin Herrenschmidt wrote:

On Fri, 2014-06-13 at 09:38 -0700, Guenter Roeck wrote:

quoted

If compiled with W=1, the following warning is seen in powerpc builds.

arch/powerpc/kernel/smp.c:750:18: warning:
	type qualifiers ignored on function return type
static const int powerpc_smt_flags(void)
                  ^

This is caused by a function returning 'const int', which doesn't
make sense to gcc. Drop 'const' to fix the problem.

This breaks the 64-bit build:

arch/powerpc/kernel/smp.c:764:2: error: initialization from incompatible pointer type [-Werror]
arch/powerpc/kernel/smp.c:764:2: error: (near initialization for 'powerpc_topology[0].sd_flags') [-Werror]

It appears that the generic definition in sched.h has this function
defined as const int, so that needs to be fixed too along with all
instances in all archs.

https://lkml.org/lkml/2014/6/12/743

Guenter