Re: [PATCH v3 27/34] mm: pagewalk: Add 'depth' parameter to pte_hole

[Dave Hansen]

On 2/27/19 9:06 AM, Steven Price wrote:
>  #ifdef CONFIG_SHMEM
>  static int smaps_pte_hole(unsigned long addr, unsigned long end,
> -		struct mm_walk *walk)
> +			  __always_unused int depth, struct mm_walk *walk)
>  {

I think this 'depth' argument is a mistake.  It's synthetic and it's
surely going to be a source of bugs.

The page table dumpers seem to be using this to dump out the "name" of a
hole which seems a bit bogus in the first place.  I'd much rather teach
the dumpers about the length of the hole, "the hole is 0x12340000 bytes
long", rather than "there's a hole at this level".