mm/compaction: rename 'start_pfn' to 'iteration_start_pfn' in compact_zone()

There are two 'start_pfn' declared in compact_zone() which have different
meanings.  Rename the second one to 'iteration_start_pfn' to prevent
confusion.

Also, remove an useless semicolon.

Link: https://lkml.kernel.org/r/20201019115044.1571-1-yanfei.xu@windriver.com
Signed-off-by: Yanfei Xu <yanfei.xu@windriver.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/compaction.c b/mm/compaction.c
index 13cb7a9..4d237a7 100644 (file)
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -2275,7 +2275,7 @@ compact_zone(struct compact_control *cc, struct capture_control *capc)
 
        while ((ret = compact_finished(cc)) == COMPACT_CONTINUE) {
                int err;
-               unsigned long start_pfn = cc->migrate_pfn;
+               unsigned long iteration_start_pfn = cc->migrate_pfn;
 
                /*
                 * Avoid multiple rescans which can happen if a page cannot be
@@ -2287,7 +2287,7 @@ compact_zone(struct compact_control *cc, struct capture_control *capc)
                 */
                cc->rescan = false;
                if (pageblock_start_pfn(last_migrated_pfn) ==
-                   pageblock_start_pfn(start_pfn)) {
+                   pageblock_start_pfn(iteration_start_pfn)) {
                        cc->rescan = true;
                }
 
@@ -2311,8 +2311,7 @@ compact_zone(struct compact_control *cc, struct capture_control *capc)
                        goto check_drain;
                case ISOLATE_SUCCESS:
                        update_cached = false;
-                       last_migrated_pfn = start_pfn;
-                       ;
+                       last_migrated_pfn = iteration_start_pfn;
                }
 
                err = migrate_pages(&cc->migratepages, compaction_alloc,