Re: [PATCH v7 02/61] radix tree: Use bottom four bits of gfp_t for flags

[Matthew Wilcox]

On Sat, Mar 03, 2018 at 07:44:36AM -0500, Jeff Layton wrote:
> > -	return root->gfp_mask & __GFP_BITS_MASK;
> > +	return root->gfp_mask & ((__GFP_BITS_MASK >> 4) << 4);
> 
> Maybe phrase this in terms of a constant like GFP_ZONEMASK here? Would
> this be more appropriate?

Yeah, that's a better idea.  This is only interim; once all radix tree users
are converted to the xarray, we stop storing GFP flags here.  So I hadn't
put much thought into it, but I'll change it.