mm: numa: Add THP migration for the NUMA working set scanning fault case build fix

Commit "Add THP migration for the NUMA working set scanning fault case"
breaks the build because HPAGE_PMD_SHIFT and HPAGE_PMD_MASK defined to
explode without CONFIG_TRANSPARENT_HUGEPAGE:

mm/migrate.c: In function 'migrate_misplaced_transhuge_page_put':
mm/migrate.c:1549: error: call to '__build_bug_failed' declared with attribute error: BUILD_BUG failed
mm/migrate.c:1564: error: call to '__build_bug_failed' declared with attribute error: BUILD_BUG failed
mm/migrate.c:1566: error: call to '__build_bug_failed' declared with attribute error: BUILD_BUG failed
mm/migrate.c:1573: error: call to '__build_bug_failed' declared with attribute error: BUILD_BUG failed
mm/migrate.c:1606: error: call to '__build_bug_failed' declared with attribute error: BUILD_BUG failed
mm/migrate.c:1648: error: call to '__build_bug_failed' declared with attribute error: BUILD_BUG failed

CONFIG_NUMA_BALANCING allows compilation without enabling transparent
hugepages, so define the dummy function for such a configuration and only
define migrate_misplaced_transhuge_page_put() when transparent hugepages
are enabled.

Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>

1 files changed, 2 insertions, 0 deletions

diff --git a/mm/migrate.c b/mm/migrate.c
index c9400960fd52..9341a501d168 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1602,7 +1602,9 @@ int migrate_misplaced_page(struct page *page, int node)
 out:
         return isolated;
 }
+#endif /* CONFIG_NUMA_BALANCING */
 
+#if defined(CONFIG_NUMA_BALANCING) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
 int migrate_misplaced_transhuge_page(struct mm_struct *mm,
                                 struct vm_area_struct *vma,
                                 pmd_t *pmd, pmd_t entry,