Re: [PATCH] dax: Fix missed PMD wakeups

[Matthew Wilcox]

On Wed, Jul 10, 2019 at 09:02:04PM +0200, Jan Kara wrote:
> +#define DAX_ENTRY_CONFLICT dax_make_entry(pfn_to_pfn_t(1), DAX_EMPTY)

I was hoping to get rid of DAX_EMPTY ... it's almost unused now.  Once
we switch to having a single DAX_LOCK value instead of a single bit,
I think it can go away, freeing up two bits.

If you really want a special DAX_ENTRY_CONFLICT, I think we can make
one in the 2..4094 range.

That aside, this looks pretty similar to the previous patch I sent, so
if you're now happy with this, let's add

#define XA_DAX_CONFLICT_ENTRY xa_mk_internal(258)

to xarray.h and do it that way?