From 95e5a2361dad6256c4dd527d34b28af07271a1cd Mon Sep 17 00:00:00 2001
From: Brennan Lamoreaux <blamoreaux@vmware.com>
Date: Tue, 12 Sep 2023 19:21:11 +0000
Subject: [PATCH] add support for sched kernel cmdline parameter

Add a new variable "sched_isolation" to manage the new
'sched' parameter on the kernel cmdline

Signed-off-by: Roye Eshed <roye.eshed@broadcom.com>
---
 profiles/realtime/realtime-variables.conf | 7 +++++++
 profiles/realtime/tuned.conf              | 8 ++++++--
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/profiles/realtime/realtime-variables.conf b/profiles/realtime/realtime-variables.conf
index d3d898d..e2e21ec 100644
--- a/profiles/realtime/realtime-variables.conf
+++ b/profiles/realtime/realtime-variables.conf
@@ -20,3 +20,10 @@ isolate_managed_irq=Y
 # (non-isolated) CPUs.
 #
 # netdev_queue_count=4
+
+#
+# Uncomment the 'sched_isolation=Y' below to improve initial process placement
+# away from isolated cores when scheduled under a cpuset containing both
+# isolated and non-isolated cores. This does not affect realtime processes.
+#
+# sched_isolation=Y
diff --git a/profiles/realtime/tuned.conf b/profiles/realtime/tuned.conf
index b51308f..769f961 100644
--- a/profiles/realtime/tuned.conf
+++ b/profiles/realtime/tuned.conf
@@ -8,7 +8,7 @@ summary=Optimize for realtime workloads
 include = network-latency
 
 [variables]
-# User is responsible for updating variables.conf with variable content such as isolated_cores=X-Y 
+# User is responsible for updating variables.conf with variable content such as isolated_cores=X-Y
 include = /etc/tuned/realtime-variables.conf
 
 isolated_cores_assert_check = \\${isolated_cores}
@@ -35,6 +35,10 @@ assert2=${f:assertion:isolated_cores contains online CPU(s):${isolated_cores_exp
 isolate_managed_irq = ${isolate_managed_irq}
 managed_irq=${f:regex_search_ternary:${isolate_managed_irq}:\b[y,Y,1,t,T]\b:managed_irq,domain,:}
 
+# Set sched_isolation
+sched_isolation = ${sched_isolation}
+sched=${f:regex_search_ternary:${sched_isolation}:\b[y,Y,1,t,T]\b:sched,:}
+
 [net]
 channels=combined ${f:check_net_queue_count:${netdev_queue_count}}
 
@@ -53,7 +57,7 @@ kernel.timer_migration = 0
 /sys/devices/system/machinecheck/machinecheck*/ignore_ce = 1
 
 [bootloader]
-cmdline_realtime=+isolcpus=${managed_irq}${isolated_cores} intel_pstate=disable nosoftlockup
+cmdline_realtime=+isolcpus=${managed_irq}${sched}${isolated_cores} intel_pstate=disable nosoftlockup
 
 [irqbalance]
 banned_cpus=${isolated_cores}
-- 
2.39.0