How about this?

Thanks,
H.Seto

Verify the pfn is valid before calling pfn_to_page(),
and cut isolation message if nothing was done.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>

Russ Anderson wrote:
> Jack Steiner wrote:
>>
>>Perhaps another status should be returned.
> 
> In this case, is any message really needed?  As you say, success is
> is misleading because nothing was done.  Failure is not accurate
> because it didn't fail.  So perhaps a third status that does not
> print any page isolation message is the best solution.