From c1087732a0cbb19866e1c864bcd31f3c7bba50fa Mon Sep 17 00:00:00 2001
From: Eric MacDonald <eric.macdonald@windriver.com>
Date: Fri, 13 May 2022 16:21:01 +0000
Subject: [PATCH] Debian KS: Force enable lowlatency trait if realtime kernel
 is detected

If the lowlatency trait is not specified yet the running kernel is RT
then force enable the lowlatency trait.

Test Plan:

PASS: Verify Debian build and install
PASS: Verify lowlatency trait force enable
PASS: Verify no force enable when kernel is not RT
PASS: Verify no force enable when lowlatency is already
      specified and RT kernel is present

Story: 2009301
Task: 45369
Signed-off-by: Eric MacDonald <eric.macdonald@windriver.com>
Change-Id: Ic5708001e80714ddf8a9c2bd774e487a5508b02e
---
 kickstart/files/kickstart.cfg | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/kickstart/files/kickstart.cfg b/kickstart/files/kickstart.cfg
index 2374e3ee..a9a98223 100644
--- a/kickstart/files/kickstart.cfg
+++ b/kickstart/files/kickstart.cfg
@@ -651,6 +651,17 @@ for trait in ${traits//,/ }; do
    esac
 done
 
+ilog "Install traits: $traits"
+
+# Force enable 'lowlatency' trait if the realtime kernel is detected ; PREEMPT_RT
+uname=$(uname -a)
+if [[ "${uname}" == *"PREEMPT_RT"* ]] ; then
+    if [ "${lowlatency}" = false ] ; then
+        wlog "forcing lowlatency trait after discovering the RT kernel"
+        lowlatency=true
+    fi
+fi
+
 [ "${controller}" = true -a "${worker}" = true ] && aio=true
 
 grep -q 'debug_kickstart' /proc/cmdline
@@ -1378,8 +1389,6 @@ for e in $*; do
 done
 fi
 
-ilog "Install traits: $traits"
-
 # Set node traits' state
 [ "${controller}" = true ] && ilog "Controller Function"
 [ "${storage}" = true ] && ilog "Storage Function"