Re: [PATCH] dax: Fix missed PMD wakeups

[Jan Kara]

On Wed 10-07-19 13:15:39, Matthew Wilcox wrote:
> 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?

Yeah, that would work for me as well. The chosen value for DAX_ENTRY_CONFLICT
was pretty arbitrary. Or we could possibly use:

#define DAX_ENTRY_CONFLICT XA_ZERO_ENTRY

so that we don't leak DAX-specific internal definition into xarray.h?

								Honza
-- 
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR