[openwrt/openwrt] netifd: add a packet steering mode matching the old script

[LEDE Commits]

nbd pushed a commit to openwrt/openwrt.git, branch main:
https://git.openwrt.org/c4d394c6cc0facba94fda5f1cc886edaf342be3a

commit c4d394c6cc0facba94fda5f1cc886edaf342be3a
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Wed Apr 24 19:16:05 2024 +0200

    netifd: add a packet steering mode matching the old script
    
    This spreads packet processing across all cores
    
    Signed-off-by: Felix Fietkau <nbd at nbd.name>
---
 .../files/usr/libexec/network/packet-steering.uc   | 23 ++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/package/network/config/netifd/files/usr/libexec/network/packet-steering.uc b/package/network/config/netifd/files/usr/libexec/network/packet-steering.uc
index 72f96024d8..025532c1c1 100755
--- a/package/network/config/netifd/files/usr/libexec/network/packet-steering.uc
+++ b/package/network/config/netifd/files/usr/libexec/network/packet-steering.uc
@@ -9,6 +9,7 @@ let eth_bias = 2.0;
 let debug = 0, do_nothing = 0;
 let disable;
 let cpus;
+let all_cpus;
 
 for (let arg in ARGV) {
 	switch (arg) {
@@ -21,6 +22,9 @@ for (let arg in ARGV) {
 	case '0':
 		disable = true;
 		break;
+	case '2':
+		all_cpus = true;
+		break;
 	}
 }
 
@@ -46,9 +50,19 @@ function set_task_cpu(pid, cpu) {
 		system(`taskset -p -c ${cpu} ${pid}`);
 }
 
+function cpu_mask(cpu)
+{
+	let mask;
+	if (cpu < 0)
+		mask = (1 << length(cpus)) - 1;
+	else
+		mask = (1 << int(cpu));
+	return sprintf("%x", mask);
+}
+
 function set_netdev_cpu(dev, cpu) {
 	let queues = glob(`/sys/class/net/${dev}/queues/rx-*/rps_cpus`);
-	let val = sprintf("%x", (1 << int(cpu)));
+	let val = cpu_mask(cpu);
 	if (disable)
 		val = 0;
 	for (let queue in queues) {
@@ -173,7 +187,12 @@ function assign_dev_cpu(dev) {
 	}
 
 	if (length(dev.netdev) > 0) {
-		let cpu = dev.rx_cpu = get_next_cpu(rx_weight, dev.napi_cpu);
+		let cpu;
+		if (all_cpus)
+			cpu = -1;
+		else
+			cpu = get_next_cpu(rx_weight, dev.napi_cpu);
+		dev.rx_cpu = cpu;
 		for (let netdev in dev.netdev)
 			set_netdev_cpu(netdev, cpu);
 	}