package/network/config/netifd/files/usr/libexec/network/packet-steering.uc

   1 #!/usr/bin/env ucode
   2 'use strict';
   3 import { glob, basename, dirname, readlink, readfile, realpath, writefile, error, open } from "fs";
   4
   5 let napi_weight = 1.0;
   6 let cpu_thread_weight = 0.75;
   7 let rx_weight = 0.75;
   8 let eth_bias = 2.0;
   9 let debug = 0, do_nothing = 0;
  10 let disable;
  11 let cpus;
  12
  13 for (let arg in ARGV) {
  14         switch (arg) {
  15         case "-d":
  16                 debug++;
  17                 break;
  18         case "-n":
  19                 do_nothing++;
  20                 break;
  21         case '0':
  22                 disable = true;
  23                 break;
  24         }
  25 }
  26
  27 function task_name(pid)
  28 {
  29         let stat = open(`/proc/${pid}/status`, "r");
  30         let line = stat.read("line");
  31         stat.close();
  32         return trim(split(line, "\t", 2)[1]);
  33 }
  34
  35 function set_task_cpu(pid, cpu) {
  36         if (disable)
  37                 cpu = join(",", map(cpus, (cpu) => cpu.id));
  38         if (debug || do_nothing)
  39                 warn(`taskset -p -c ${cpu} ${task_name(pid)}\n`);
  40         if (!do_nothing)
  41                 system(`taskset -p -c ${cpu} ${pid}`);
  42 }
  43
  44 function set_netdev_cpu(dev, cpu) {
  45         let queues = glob(`/sys/class/net/${dev}/queues/rx-*/rps_cpus`);
  46         let val = sprintf("%x", (1 << int(cpu)));
  47         if (disable)
  48                 val = 0;
  49         for (let queue in queues) {
  50                 if (debug || do_nothing)
  51                         warn(`echo ${val} > ${queue}\n`);
  52                 if (!do_nothing)
  53                         writefile(queue, `${val}`);
  54         }
  55 }
  56
  57 function task_device_match(name, device)
  58 {
  59         let napi_match = match(name, /napi\/([^-+])-\d+/);
  60         if (!napi_match)
  61                 napi_match = match(name, /mt76-tx (phy\d+)/);
  62         if (napi_match &&
  63             (index(device.phy, napi_match[1]) >= 0 ||
  64              index(device.netdev, napi_match[1]) >= 0))
  65                 return true;
  66
  67         if (device.driver == "mtk_soc_eth" && match(name, /napi\/mtk_eth-/))
  68                 return true;
  69
  70         return false;
  71 }
  72
  73 cpus = map(glob("/sys/bus/cpu/devices/*"), (path) => {
  74         return {
  75                 id: int(match(path, /.*cpu(\d+)/)[1]),
  76                 core: int(trim(readfile(`${path}/topology/core_id`))),
  77                 load: 0.0,
  78         };
  79 });
  80
  81 cpus = slice(cpus, 0, 64);
  82 if (length(cpus) < 2)
  83         exit(0);
  84
  85 function cpu_add_weight(cpu_id, weight)
  86 {
  87         let cpu = cpus[cpu_id];
  88         cpu.load += weight;
  89         for (let sibling in cpus) {
  90                 if (sibling == cpu || sibling.core != cpu.core)
  91                         continue;
  92                 sibling.load += weight * cpu_thread_weight;
  93         }
  94 }
  95
  96 function get_next_cpu(weight, prev_cpu)
  97 {
  98         if (disable)
  99                 return 0;
 100
 101         let sort_cpus = sort(slice(cpus), (a, b) => a.load - b.load);
 102         let idx = 0;
 103
 104         if (prev_cpu != null && sort_cpus[idx].id == prev_cpu)
 105                 idx++;
 106
 107         let cpu = sort_cpus[idx].id;
 108         cpu_add_weight(cpu, weight);
 109         return cpu;
 110 }
 111
 112 let phys_devs = {};
 113 let netdev_phys = {};
 114 let netdevs = map(glob("/sys/class/net/*"), (dev) => basename(dev));
 115
 116 for (let dev in netdevs) {
 117         let pdev_path = realpath(`/sys/class/net/${dev}/device`);
 118         if (!pdev_path)
 119                 continue;
 120
 121         if (length(glob(`/sys/class/net/${dev}/lower_*`)) > 0)
 122                 continue;
 123
 124         let pdev = phys_devs[pdev_path];
 125         if (!pdev) {
 126                 pdev = phys_devs[pdev_path] = {
 127                         path: pdev_path,
 128                         driver: basename(readlink(`${pdev_path}/driver`)),
 129                         netdev: [],
 130                         phy: [],
 131                         tasks: [],
 132                 };
 133         }
 134
 135         let phyidx = trim(readfile(`/sys/class/net/${dev}/phy80211/index`));
 136         if (phyidx != null) {
 137                 let phy = `phy${phyidx}`;
 138                 if (index(pdev.phy, phy) < 0)
 139                         push(pdev.phy, phy);
 140         }
 141
 142         push(pdev.netdev, dev);
 143         netdev_phys[dev] = pdev;
 144 }
 145
 146 for (let path in glob("/proc/*/exe")) {
 147         readlink(path);
 148         if (error() != "No such file or directory")
 149                 continue;
 150
 151         let pid = basename(dirname(path));
 152         let name = task_name(pid);
 153         for (let devname in phys_devs) {
 154                 let dev = phys_devs[devname];
 155                 if (!task_device_match(name, dev))
 156                         continue;
 157
 158                 push(dev.tasks, pid);
 159                 break;
 160         }
 161 }
 162
 163 function assign_dev_cpu(dev) {
 164         if (length(dev.tasks) > 0) {
 165                 let cpu = dev.napi_cpu = get_next_cpu(napi_weight);
 166                 for (let task in dev.tasks)
 167                         set_task_cpu(task, cpu);
 168         }
 169
 170         if (length(dev.netdev) > 0) {
 171                 let cpu = dev.rx_cpu = get_next_cpu(rx_weight, dev.napi_cpu);
 172                 for (let netdev in dev.netdev)
 173                         set_netdev_cpu(netdev, cpu);
 174         }
 175 }
 176
 177 // Assign ethernet devices first
 178 for (let devname in phys_devs) {
 179         let dev = phys_devs[devname];
 180         if (!length(dev.phy))
 181                 assign_dev_cpu(dev);
 182 }
 183
 184 // Add bias to avoid assigning other tasks to CPUs with ethernet NAPI
 185 for (let devname in phys_devs) {
 186         let dev = phys_devs[devname];
 187         if (!length(dev.tasks) || dev.napi_cpu == null)
 188                 continue;
 189         cpu_add_weight(dev.napi_cpu, eth_bias);
 190 }
 191
 192 // Assign WLAN devices
 193 for (let devname in phys_devs) {
 194         let dev = phys_devs[devname];
 195         if (length(dev.phy) > 0)
 196                 assign_dev_cpu(dev);
 197 }
 198
 199 if (debug > 1)
 200         warn(sprintf("devices: %.J\ncpus: %.J\n", phys_devs, cpus));