[PATCH] powerpc/64: implement a slice mask cache

[Nicholas Piggin]

On Sat, 23 Jul 2016 18:49:06 +1000
Benjamin Herrenschmidt <benh at kernel.crashing.org> wrote:

> On Sat, 2016-07-23 at 17:10 +1000, Nicholas Piggin wrote:
> > I wanted to avoid doing more work under slice_convert_lock, but
> > we should just make that a per-mm lock anyway shouldn't we?  
> 
> Aren't the readers under the mm sem taken for writing or has this
> changed ?


I don't think this has changed, but I look at the writers now,
which aren't synchronized by mm sem. But neither are readers
under the slice_convert_lock, so I'm looking at what the locking
actually is. Is it just using atomicity of dword stores vs loads?

Thanks,
Nick