diff options
| author | Ben Widawsky <ben.widawsky@intel.com> | 2020-06-10 18:41:50 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-10 19:14:18 -0700 |
| commit | 496df3d3ab8a407f83330fb8d7160a5f91898c55 (patch) | |
| tree | 282b6daef9d09f9a0e1a89aed9f99c568fd6e6eb | |
| parent | cc989e78472e29c69b196d6985e718c8834027b7 (diff) | |
mm: add comments on pglist_data zones
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
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200520205443.2757414-1-ben.widawsky@intel.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | include/linux/mmzone.h | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index df1f08486d81..c4c37fd12104 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -660,9 +660,21 @@ 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 |