[PATCH] s390/mm: correct pgtable_bytes on page table downgrade

[Martin Schwidefsky]

The downgrade of a page table from 3 levels to 2 levels for a 31-bit compat
process removes a pmd table which has to be counted against pgtable_bytes.

Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
---
 arch/s390/mm/pgalloc.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/s390/mm/pgalloc.c b/arch/s390/mm/pgalloc.c
index 814f26520aa2..6791562779ee 100644
--- a/arch/s390/mm/pgalloc.c
+++ b/arch/s390/mm/pgalloc.c
@@ -131,6 +131,7 @@ void crst_table_downgrade(struct mm_struct *mm)
 	}
 
 	pgd = mm->pgd;
+	mm_dec_nr_pmds(mm);
 	mm->pgd = (pgd_t *) (pgd_val(*pgd) & _REGION_ENTRY_ORIGIN);
 	mm->context.asce_limit = _REGION3_SIZE;
 	mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH |
-- 
2.16.4
-- 
blue skies,
   Martin.

"Reality continues to ruin my life." - Calvin.