s390/kvm: bad rss-counter state

commit c3f0327f8e9d7a503f0d64573c311eddd61f197d
    mm: add rss counters consistency check
detected the following problem with kvm on s390:

BUG: Bad rss-counter state mm:00000004f73ef000 idx:0 val:-10
BUG: Bad rss-counter state mm:00000004f73ef000 idx:1 val:-5

We have to make sure that we accumulate all rss values into
the mm before we replace the mm to avoid triggering this (harmless)
bug message.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 6e765bf..a3db5a3 100644 (file)
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -822,6 +822,8 @@ int s390_enable_sie(void)
 
        /* we copy the mm and let dup_mm create the page tables with_pgstes */
        tsk->mm->context.alloc_pgste = 1;
+       /* make sure that both mms have a correct rss state */
+       sync_mm_rss(tsk->mm);
        mm = dup_mm(tsk);
        tsk->mm->context.alloc_pgste = 0;
        if (!mm)