Merge pull request #345 from pjps/RHBZ#1947858

RHBZ#1947858 profiles: improve realtime verify functions

profiles/realtime-virtual-guest/script.sh

@@ -2,13 +2,8 @@
 
 . /usr/lib/tuned/functions
 
-KTIMER_LOCKLESS_FILE=/sys/kernel/ktimer_lockless_check
-
 start() {
-    if [ -f $KTIMER_LOCKLESS_FILE ]; then
-        echo 1 > $KTIMER_LOCKLESS_FILE
-    fi
-    return "$?"
+    return 0
 }
 
 stop() {
@@ -16,7 +11,7 @@ stop() {
 }
 
 verify() {
-    return "$?"
+    return 0
 }
 
 process $@

profiles/realtime-virtual-guest/tuned.conf

@@ -36,6 +36,11 @@ group.ktimersoftd=0:f:3:*:ktimersoftd.*
 
 ps_blacklist=ksoftirqd.*;rcuc.*;rcub.*;ktimersoftd.*
 
+[sysfs]
+# Perform lockless check for timer softirq on isolated CPUs.
+#
+/sys/kernel/ktimer_lockless_check = 1
+
 [script]
 script=${i:PROFILE_DIR}/script.sh
 

profiles/realtime-virtual-host/script.sh

@@ -2,36 +2,39 @@
 
 . /usr/lib/tuned/functions
 
-KTIMER_LOCKLESS_FILE=/sys/kernel/ktimer_lockless_check
-
 start() {
     setup_kvm_mod_low_latency
-
-    disable_ksm
-
-    if [ -f $KTIMER_LOCKLESS_FILE ]; then
-        echo 1 > $KTIMER_LOCKLESS_FILE
-    fi
-
     return 0
 }
 
 stop() {
     if [ "$1" = "full_rollback" ]; then
         teardown_kvm_mod_low_latency
-        enable_ksm
     fi
     return "$?"
 }
 
 verify() {
+    retval=0
+
+    # set via /etc/modprobe.d/kvm.conf and /etc/modprobe.d/kvm.rt.tuned.conf
     if [ -f /sys/module/kvm/parameters/kvmclock_periodic_sync ]; then
-        test "$(cat /sys/module/kvm/parameters/kvmclock_periodic_sync)" = 0
-        retval=$?
+        kps=$(cat /sys/module/kvm/parameters/kvmclock_periodic_sync)
+        if [ "$kps" = "N" -o "$kps" = "0" ]; then
+            echo "  kvmclock_periodic_sync:($kps): disabled: okay"
+        else
+            echo "  kvmclock_periodic_sync:($kps): enabled: expected N(0)"
+            retval=1
+        fi
     fi
-    if [ $retval -eq 0 -a -f /sys/module/kvm_intel/parameters/ple_gap ]; then
-        test "$(cat /sys/module/kvm_intel/parameters/ple_gap)" = 0
-        retval=$?
+    if [ -f /sys/module/kvm_intel/parameters/ple_gap ]; then
+        ple_gap=$(cat /sys/module/kvm_intel/parameters/ple_gap)
+        if [ $ple_gap -eq 0 ]; then
+            echo "  ple_gap:($ple_gap): disabled: okay"
+        else
+            echo "  ple_gap:($ple_gap): enabled: expected 0"
+            retval=1
+        fi
     fi
     return $retval
 }

profiles/realtime-virtual-host/tuned.conf

@@ -41,6 +41,18 @@ group.ktimersoftd=0:f:3:*:ktimersoftd.*
 
 ps_blacklist=ksoftirqd.*;rcuc.*;rcub.*;ktimersoftd.*;.*pmd.*;.*PMD.*;^DPDK;.*qemu-kvm.*
 
+[sysfs]
+# Stop kernel same page merge (KSM) daemon, it may introduce latencies.
+#
+# 0: stop ksmd, keep merged pages
+# 1: run ksmd
+# 2: stop ksmd, unmerge all pages
+/sys/kernel/mm/ksm/run = 2
+
+# Perform lockless check for timer softirq on isolated CPUs.
+#
+/sys/kernel/ktimer_lockless_check = 1
+
 [script]
 script=${i:PROFILE_DIR}/script.sh
 

profiles/realtime/script.sh

@@ -11,8 +11,12 @@ stop() {
 }
 
 verify() {
-    tuna -c "$TUNED_isolated_cores" -P
-    return "$?"
+    retval=0
+    if [ "$TUNED_isolated_cores" ]; then
+        tuna -c "$TUNED_isolated_cores" -P > /dev/null 2>&1
+        retval=$?
+    fi
+    return $retval
 }
 
 process $@