Hi all,

[Also reported by Randy Dunlap.]

After merging the akpm-current tree, today's linux-next build (arm
multi_v7_defconfig) failed like this:

mm/migrate.c: In function 'migrate_pages':
mm/migrate.c:1528:19: error: 'THP_MIGRATION_SUCCESS' undeclared (first use in this function); did you mean 'PGMIGRATE_SUCCESS'?
 1528 |   count_vm_events(THP_MIGRATION_SUCCESS, nr_thp_succeeded);
      |                   ^~~~~~~~~~~~~~~~~~~~~
      |                   PGMIGRATE_SUCCESS
mm/migrate.c:1528:19: note: each undeclared identifier is reported only once for each function it appears in
mm/migrate.c:1530:19: error: 'THP_MIGRATION_FAILURE' undeclared (first use in this function); did you mean 'SWP_MIGRATION_WRITE'?
 1530 |   count_vm_events(THP_MIGRATION_FAILURE, nr_thp_failed);
      |                   ^~~~~~~~~~~~~~~~~~~~~
      |                   SWP_MIGRATION_WRITE
mm/migrate.c:1532:19: error: 'THP_MIGRATION_SPLIT' undeclared (first use in this function); did you mean 'SWP_MIGRATION_WRITE'?
 1532 |   count_vm_events(THP_MIGRATION_SPLIT, nr_thp_split);
      |                   ^~~~~~~~~~~~~~~~~~~
      |                   SWP_MIGRATION_WRITE

Caused by commit

  f85bb1e35327 ("mm/vmstat: add events for THP migration without split")

I have reverted that commit (and its followup fix) for today.

-- 
Cheers,
Stephen Rothwell