Re: [PATCH 01/31] huge tmpfs: prepare counts in meminfo, vmstat and SysRq-m

[Kirill A. Shutemov]

On Tue, Apr 05, 2016 at 02:12:26PM -0700, Hugh Dickins wrote:
> ShmemFreeHoles will show the wastage from using huge pages for small, or
> sparsely occupied, or unrounded files: wastage not included in Shmem or
> MemFree, but will be freed under memory pressure.  (But no count for the
> partially occupied portions of huge pages: seems less important, but
> could be added.)

And here first difference in interfaces comes: I don't have an
equivalent in my implementation, as I don't track such information.
It looks like an implementation detail for team-pages based huge tmpfs.

We don't track anything similar for anon-THP.

> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -3830,6 +3830,11 @@ out:
>  }
>  
>  #define K(x) ((x) << (PAGE_SHIFT-10))
> +#ifdef CONFIG_TRANSPARENT_HUGEPAGE
> +#define THPAGE_PMD_NR	HPAGE_PMD_NR
> +#else
> +#define THPAGE_PMD_NR	0	/* Avoid BUILD_BUG() */
> +#endif

I've just put THP-related counters on separate line and wrap it into
#ifdef.


-- 
 Kirill A. Shutemov