On Tue, 2017-08-22 at 15:18 +0200, Frederic Barrat wrote:

quoted

Or you could just incrementer my counter. Just make sure you increment
it at most once per CXL context and decrement when the context is gone.

Ah great, I didn't dare messing with your counter, it makes it easier. 
Arguably what happens on those accelerators is pretty close to an active 
cpu.

Once it is merged, I'm going to have to backport your patch (and an 
update to mine) to the p9-supporting distros. From a quick look, your 
patch, i.e."[PATCH 5/6] powerpc/mm: Optimize detection of thread local 
mm's" is completely independent from the rest of the series, right?

We also need the memory barrier fix but yes.

Cheers,
Ben.