[SRU][F][G][H][PATCH 1/1] s390/vtime: fix increased steal time accounting

[frank.heimes at canonical.com]

From: Gerald Schaefer <gerald.schaefer at linux.ibm.com>

BugLink: https://bugs.launchpad.net/bugs/1921498

Commit 152e9b8676c6e ("s390/vtime: steal time exponential moving average")
inadvertently changed the input value for account_steal_time() from
"cputime_to_nsecs(steal)" to just "steal", resulting in broken increased
steal time accounting.

Fix this by changing it back to "cputime_to_nsecs(steal)".

Fixes: 152e9b8676c6e ("s390/vtime: steal time exponential moving average")
Cc: <stable at vger.kernel.org> # 5.1
Reported-by: Sabine Forkel <sabine.forkel at de.ibm.com>
Reviewed-by: Heiko Carstens <hca at linux.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer at linux.ibm.com>
Signed-off-by: Heiko Carstens <hca at linux.ibm.com>
(cherry picked from commit d54cb7d54877d529bc1e0e1f47a3dd082f73add3)
Signed-off-by: Frank Heimes <frank.heimes at canonical.com>
---
 arch/s390/kernel/vtime.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c
index 3e72f955bff7..6e60cc2443b2 100644
--- a/arch/s390/kernel/vtime.c
+++ b/arch/s390/kernel/vtime.c
@@ -217,7 +217,7 @@ void vtime_flush(struct task_struct *tsk)
 	avg_steal = S390_lowcore.avg_steal_timer / 2;
 	if ((s64) steal > 0) {
 		S390_lowcore.steal_timer = 0;
-		account_steal_time(steal);
+		account_steal_time(cputime_to_nsecs(steal));
 		avg_steal += steal;
 	}
 	S390_lowcore.avg_steal_timer = avg_steal;
-- 
2.25.1