mm/page_alloc: integrate classzone_idx and high_zoneidx

classzone_idx is just different name for high_zoneidx now.  So, integrate
them and add some comment to struct alloc_context in order to reduce
future confusion about the meaning of this variable.

The accessor, ac_classzone_idx() is also removed since it isn't needed
after integration.

In addition to integration, this patch also renames high_zoneidx to
highest_zoneidx since it represents more precise meaning.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Baoquan He <bhe@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Ye Xiaolong <xiaolong.ye@intel.com>
Link: http://lkml.kernel.org/r/1587095923-7515-3-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 4 deletions

diff --git a/include/linux/compaction.h b/include/linux/compaction.h
index 4b898cdbdf05..3ed2f22b588a 100644
--- a/include/linux/compaction.h
+++ b/include/linux/compaction.h
@@ -97,7 +97,7 @@ extern enum compact_result try_to_compact_pages(gfp_t gfp_mask,
 		struct page **page);
 extern void reset_isolation_suitable(pg_data_t *pgdat);
 extern enum compact_result compaction_suitable(struct zone *zone, int order,
-		unsigned int alloc_flags, int classzone_idx);
+		unsigned int alloc_flags, int highest_zoneidx);
 
 extern void defer_compaction(struct zone *zone, int order);
 extern bool compaction_deferred(struct zone *zone, int order);
@@ -182,7 +182,7 @@ bool compaction_zonelist_suitable(struct alloc_context *ac, int order,
 
 extern int kcompactd_run(int nid);
 extern void kcompactd_stop(int nid);
-extern void wakeup_kcompactd(pg_data_t *pgdat, int order, int classzone_idx);
+extern void wakeup_kcompactd(pg_data_t *pgdat, int order, int highest_zoneidx);
 
 #else
 static inline void reset_isolation_suitable(pg_data_t *pgdat)
@@ -190,7 +190,7 @@ static inline void reset_isolation_suitable(pg_data_t *pgdat)
 }
 
 static inline enum compact_result compaction_suitable(struct zone *zone, int order,
-					int alloc_flags, int classzone_idx)
+					int alloc_flags, int highest_zoneidx)
 {
 	return COMPACT_SKIPPED;
 }
@@ -232,7 +232,8 @@ static inline void kcompactd_stop(int nid)
 {
 }
 
-static inline void wakeup_kcompactd(pg_data_t *pgdat, int order, int classzone_idx)
+static inline void wakeup_kcompactd(pg_data_t *pgdat,
+				int order, int highest_zoneidx)
 {
 }