From 637f4d283c419cb7eeacbc1538f61b8216c7a51a Mon Sep 17 00:00:00 2001
From: Suneeth D <Suneeth.D@amd.com>
Date: Mon, 17 Aug 2026 10:54:27 +0000
Subject: [PATCH] Enable numactl for will-it-scale testcases

Few testcases especially memory based testcases shows too much run-2-run
variance when ran for say 10 iterations. But when run with the command
prefix "$numactl --membind=0" the variance goes away.

This patch adds numactl parameter which can be set to true(default:
false) in the job.yaml based on user's requirements.

Signed-off-by: Suneeth D <Suneeth.D@amd.com>
---
 programs/will-it-scale/meta.yaml   |  6 ++++++
 programs/will-it-scale/pkg/depends |  1 +
 programs/will-it-scale/run         | 13 ++++++++++++-
 3 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/programs/will-it-scale/meta.yaml b/programs/will-it-scale/meta.yaml
index 3eaa45527..a4e9bc81e 100644
--- a/programs/will-it-scale/meta.yaml
+++ b/programs/will-it-scale/meta.yaml
@@ -19,6 +19,10 @@ description: |
   warmup period before which an average is taken. The averaging period can be
   changed with the -s option, which by default is 5 seconds.
 
+  numactl is a boolean parameter, if true, confine the tasks and their memory to
+  a single node (numa_node, 0 by default) so that the results are not perturbed
+  by remote memory accesses. Default to false.
+
 homepage: https://github.com/antonblanchard/will-it-scale
 
 parameters:
@@ -27,6 +31,8 @@ parameters:
   mode: [process, thread, both]
   nr_task:
   smt: [0, 1]
+  numactl:
+  numa_node:
 
 results:
   will-it-scale.scalability:
diff --git a/programs/will-it-scale/pkg/depends b/programs/will-it-scale/pkg/depends
index 83fed7f70..283ea7a84 100644
--- a/programs/will-it-scale/pkg/depends
+++ b/programs/will-it-scale/pkg/depends
@@ -1,3 +1,4 @@
 libhwloc5
 linux-perf
+numactl
 python-minimal
diff --git a/programs/will-it-scale/run b/programs/will-it-scale/run
index 86f7233e0..bd7424adf 100755
--- a/programs/will-it-scale/run
+++ b/programs/will-it-scale/run
@@ -5,6 +5,8 @@
 # - nr_task
 # - no_affinity
 # - smt
+# - numactl
+# - numa_node
 
 . $LKP_SRC/lib/debug.sh
 . $LKP_SRC/lib/env.sh
@@ -47,7 +49,16 @@ fi
 
 [[ -n "$no_affinity" ]] || no_affinity=0
 
+# Confine both the tasks' memory to $numa_node, so that the results are
+# not perturbed by remote memory accesses.
+numactl_prefix=
+if [[ "$numactl" = true ]]; then
+	has_cmd numactl || die "numactl is not found in $PATH"
+	[[ -n "$numa_node" ]] || numa_node=0
+	numactl_prefix="numactl --membind=$numa_node --"
+fi
+
 ulimit -n 65536
 
 has_cmd python3 || die "python3 is not found in $PATH"
-log_cmd python3 ./runtest.py $test $duration $mode $no_affinity $smt $threads_to_iterate
+log_cmd $numactl_prefix python3 ./runtest.py $test $duration $mode $no_affinity $smt $threads_to_iterate