percpu_foreach() does not execute remotely

[Jason Thorpe <thorpej%me.com@localhost>]

So, percpu_foreach() is pretty handy for enumerating data that's managed on a per-cpu basis.  But there's a problem ... it does not actually execute the callback on the remote CPU, instead getting a pointer to the remote data and accessing it directly.

Does this seem like a problem to anyone else?  I think we need to at least provide a variant that is safe to use with xcalls (I can see an argument for having the current version that does not rely on xcalls).

-- thorpej