On Wed, May 20, 2020 at 01:54:43PM -0700, Ben Widawsky wrote:
> While making other modifications it was easy to confuse the two struct
> members node_zones and node_zonelists. For those already familiar with
> the code, this might seem to be a silly patch, but it's quite helpful to
> disambiguate the similar-sounding fields
>
> While here, add a small comment on why nr_zones isn't simply MAX_NR_ZONES
It seems like a real shame to write all this excellent documentation
and not format it as kernel-doc.
> Signed-off-by: Ben Widawsky <ben.widawsky@xxxxxxxxx>
> ---
> include/linux/mmzone.h | 14 +++++++++++++-
> 1 file changed, 13 insertions(+), 1 deletion(-)
>
> diff --git include/linux/mmzone.h include/linux/mmzone.h
> index 1b9de7d220fb..4f7c95e9bad8 100644
> --- include/linux/mmzone.h
> +++ include/linux/mmzone.h
> @@ -665,9 +665,21 @@ struct deferred_split {
> * per-zone basis.
> */
> typedef struct pglist_data {
> + /*
> + * node_zones contains just the zones for THIS node. Not all of the
> + * zones may be populated, but it is the full list. It is referenced by
> + * this node's node_zonelists as well as other node's node_zonelists.
> + */
> struct zone node_zones[MAX_NR_ZONES];
> +
> + /*
> + * node_zonelists contains references to all zones in all nodes.
> + * Generally the first zones will be references to this node's
> + * node_zones.
> + */
> struct zonelist node_zonelists[MAX_ZONELISTS];
> - int nr_zones;
> +
> + int nr_zones; /* number of populated zones in this node */
> #ifdef CONFIG_FLAT_NODE_MEM_MAP /* means !SPARSEMEM */
> struct page *node_mem_map;
> #ifdef CONFIG_PAGE_EXTENSION
> --
> 2.26.2
>
>
