From 2d128922ba0b8e2d24e676bc99a1db9a2abcf06f Mon Sep 17 00:00:00 2001
From: prabhataravind <108555774+prabhataravind@users.noreply.github.com>
Date: Fri, 8 Nov 2024 12:06:31 -0800
Subject: [PATCH] [image_config]: Enable Receive Packet Steering (RPS) (#20211)

[image_config]: Enable Receive Packet Steering (RPS)

Signed-off-by: Prabhat Aravind <paravind@microsoft.com>
---
 .../build_templates/sonic_debian_extension.j2 |   8 +-
 files/image_config/rps/rps.py                 | 109 ++++++++++++++++++
 files/image_config/udev/rules.d/99-rps.rules  |   1 +
 3 files changed, 117 insertions(+), 1 deletion(-)
 create mode 100755 files/image_config/rps/rps.py
 create mode 100644 files/image_config/udev/rules.d/99-rps.rules

diff --git a/files/build_templates/sonic_debian_extension.j2 b/files/build_templates/sonic_debian_extension.j2
index aa427f6157c1..8d529b2ec09e 100644
--- a/files/build_templates/sonic_debian_extension.j2
+++ b/files/build_templates/sonic_debian_extension.j2
@@ -515,8 +515,10 @@ sudo cp $IMAGE_CONFIGS/resolv-config/update-containers $FILESYSTEM_ROOT/etc/reso
 sudo cp $IMAGE_CONFIGS/interfaces/init_interfaces $FILESYSTEM_ROOT/etc/network/interfaces
 sudo mkdir -p $FILESYSTEM_ROOT/etc/network/interfaces.d
 
-# System'd network udev rules
+# Systemd network udev rules
 sudo cp $IMAGE_CONFIGS/systemd/network/* $FILESYSTEM_ROOT_ETC/systemd/network/
+sudo mkdir -p $FILESYSTEM_ROOT_ETC/udev/rules.d
+sudo cp $IMAGE_CONFIGS/udev/rules.d/* $FILESYSTEM_ROOT_ETC/udev/rules.d/
 
 # copy core file uploader files
 sudo cp $IMAGE_CONFIGS/corefile_uploader/core_uploader.service $FILESYSTEM_ROOT_USR_LIB_SYSTEMD_SYSTEM
@@ -725,6 +727,10 @@ sudo cp $IMAGE_CONFIGS/backend_acl/backend-acl.service $FILESYSTEM_ROOT_USR_LIB_
 sudo cp $IMAGE_CONFIGS/backend_acl/backend_acl.py $FILESYSTEM_ROOT/usr/bin/backend_acl.py
 echo "backend-acl.service" | sudo tee -a $GENERATED_SERVICE_FILE
 
+# Copy RPS script file
+sudo cp $IMAGE_CONFIGS/rps/rps.py $FILESYSTEM_ROOT/usr/bin/rps.py
+sudo chmod 755 $FILESYSTEM_ROOT/usr/bin/rps.py
+
 # Copy SNMP configuration files
 sudo cp $IMAGE_CONFIGS/snmp/snmp.yml $FILESYSTEM_ROOT/etc/sonic/
 
diff --git a/files/image_config/rps/rps.py b/files/image_config/rps/rps.py
new file mode 100755
index 000000000000..df1dbf5a3ccd
--- /dev/null
+++ b/files/image_config/rps/rps.py
@@ -0,0 +1,109 @@
+#!/usr/bin/env python3
+"""
+    Script to enable Receive Packet Steering (RPS).
+    This script reads the number of available CPUs in the system
+    and configures RPS on all front-panel ports using sysfs.
+"""
+import os
+import sys
+import syslog
+import argparse
+
+def write_syslog(message, *args):
+    """
+    Write a message to syslog.
+
+    Args:
+        message (str): Message string to be logged
+        args: Optional args
+
+    Returns:
+        None
+    """
+
+    if args:
+        message %= args
+    syslog.syslog(syslog.LOG_NOTICE, message)
+
+
+def get_num_cpus():
+    """
+    Get number of CPUs in the system.
+
+    Returns:
+        ncpus (int): Number of CPUs
+    """
+    ncpus = 0
+    cpu_count = os.cpu_count()
+    if cpu_count is not None:
+        ncpus = cpu_count
+
+    return ncpus
+
+
+def get_cpumask(ncpus):
+    """
+    Get a hex cpumask string.
+
+    Args:
+        ncpus (int): Number of CPUs
+
+    Returns:
+        cpu_mask (str): CPU mask as hex string
+    """
+    cpu_mask = '0'
+    if isinstance(ncpus, int) and ncpus >= 0:
+        cpu_mask = hex(pow(2, ncpus) - 1)[2:]
+
+    return cpu_mask
+
+
+def configure_rps(intf):
+    """
+    Configure Receive Packet Steering (RPS)
+
+    Returns:
+        rv (int): zero for success and non-zero otherwise
+    """
+    rv = 0
+    NET_DIR_PATH = "/sys/class/net"
+
+    num_cpus = get_num_cpus()
+    if not num_cpus:
+        rv = -1
+        return rv
+
+    cpumask = get_cpumask(num_cpus)
+    if cpumask == '0':
+        # Nothing to do
+        return rv
+
+    queues_path = os.path.join(NET_DIR_PATH, intf, "queues")
+    queues = os.listdir(queues_path)
+    num_rx_queues = len([q for q in queues if q.startswith("rx")])
+    for q in range(num_rx_queues):
+        rps_cpus_path = os.path.join(queues_path, "rx-{}", "rps_cpus").format(q)
+        with open(rps_cpus_path, 'w') as file:
+            file.write(cpumask)
+
+    return rv
+
+
+def main():
+    rv = -1
+    try:
+        parser = argparse.ArgumentParser(description='Configure RPS.')
+        parser.add_argument('interface', type=str, help='Network interface')
+        args = parser.parse_args()
+        rv = configure_rps(args.interface)
+        write_syslog("configure_rps {} for interface {}".format
+                    ("failed" if rv else "successful", args.interface))
+    except Exception as e:
+        write_syslog("configure_rps exception: {}".format(str(e)))
+
+    sys.exit(rv)
+
+
+if __name__ == "__main__":
+    main()
+
diff --git a/files/image_config/udev/rules.d/99-rps.rules b/files/image_config/udev/rules.d/99-rps.rules
new file mode 100644
index 000000000000..2e98cfe7e07d
--- /dev/null
+++ b/files/image_config/udev/rules.d/99-rps.rules
@@ -0,0 +1 @@
+ACTION=="add", SUBSYSTEM=="net", KERNEL=="Ethernet*", RUN+="/usr/bin/rps.py %k"