s390/hiperdispatch: Decrease steal time threshold

Higher steal time thresholds favor low utilization scenarios, which is not
the common case for s390. Set steal time threshold to a lower value to
prioritize vertical high and medium CPUs sooner and allow high utilization
scenarios to benefit from it.

Suggested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Mete Durlu <meted@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

diff --git a/arch/s390/kernel/hiperdispatch.c b/arch/s390/kernel/hiperdispatch.c
index 2507bc3f775741de20dd06a3be7789693dfe4f5a..7ad134cc9ad3326706201812ef631ead8ee0abd2 100644 (file)
--- a/arch/s390/kernel/hiperdispatch.c
+++ b/arch/s390/kernel/hiperdispatch.c
@@ -65,7 +65,7 @@
 
 #define HD_DELAY_FACTOR                        (4)
 #define HD_DELAY_INTERVAL              (HZ / 4)
-#define HD_STEAL_THRESHOLD             30
+#define HD_STEAL_THRESHOLD             10
 #define HD_STEAL_AVG_WEIGHT            16
 
 static cpumask_t hd_vl_coremask;       /* Mask containing all vertical low COREs */