Re: [PATCH v19 3/7] xbitmap: add more operations

[Matthew Wilcox]

On Tue, Dec 12, 2017 at 07:55:55PM +0800, Wei Wang wrote:
> +int xb_preload_and_set_bit(struct xb *xb, unsigned long bit, gfp_t gfp);

I'm struggling to understand when one would use this.  The xb_ API
requires you to handle your own locking.  But specifying GFP flags
here implies you can sleep.  So ... um ... there's no locking?

> +void xb_clear_bit_range(struct xb *xb, unsigned long start, unsigned long end);

That's xb_zero() which you deleted with the previous patch ... remember,
keep things as close as possible to the bitmap API.