src/sd_rr.c

   1 /*
   2  * Lightweight Autonomic Network Architecture
   3  *
   4  * Round robin scheduler.
   5  *
   6  * Copyright 2011 Daniel Borkmann <dborkma@tik.ee.ethz.ch>,
   7  * Swiss federal institute of technology (ETH Zurich)
   8  * Subject to the GPL.
   9  */
  10
  11 #include <linux/module.h>
  12 #include <linux/kernel.h>
  13 #include <linux/cache.h>
  14 #include <linux/cpumask.h>
  15 #include <linux/spinlock.h>
  16
  17 #include "xt_sched.h"
  18 #include "xt_engine.h"
  19
  20 static unsigned long cpu;
  21 static unsigned long cpu_max;
  22 static spinlock_t lock;
  23 static int initialized = 0;
  24
  25 static int ppe_rr_init(void)
  26 {
  27         if (likely(initialized))
  28                 return 0;
  29         cpu = 0;
  30         cpu_max = num_online_cpus();
  31         spin_lock_init(&lock);
  32         initialized = 1;
  33         return 0;
  34 }
  35
  36 static int ppe_rr_sched(struct sk_buff *skb, enum path_type dir)
  37 {
  38         unsigned long __cpu, flags;
  39
  40         spin_lock_irqsave(&lock, flags);
  41         __cpu = cpu++;
  42         if (cpu == cpu_max)
  43                 cpu = 0;
  44         spin_unlock_irqrestore(&lock, flags);
  45
  46         switch (dir) {
  47         case TYPE_EGRESS:
  48                 enqueue_egress_on_engine(skb, __cpu);
  49                 break;
  50         case TYPE_INGRESS:
  51                 enqueue_ingress_on_engine(skb, __cpu);
  52                 break;
  53         default:
  54                 return PPE_ERROR;
  55         }
  56         return PPE_SUCCESS;
  57 }
  58
  59 static void ppe_rr_cleanup(void)
  60 {
  61         initialized = 0;
  62 }
  63
  64 static struct ppesched_discipline_ops ppe_rr_ops __read_mostly = {
  65         .discipline_init = ppe_rr_init,
  66         .discipline_sched = ppe_rr_sched,
  67         .discipline_cleanup = ppe_rr_cleanup,
  68 };
  69
  70 static struct ppesched_discipline ppe_rr __read_mostly = {
  71         .name = "roundrobin",
  72         .ops = &ppe_rr_ops,
  73         .owner = THIS_MODULE,
  74 };
  75
  76 static int __init init_ppe_rr_module(void)
  77 {
  78         return ppesched_discipline_register(&ppe_rr);
  79 }
  80
  81 static void __exit cleanup_ppe_rr_module(void)
  82 {
  83         return ppesched_discipline_unregister(&ppe_rr);
  84 }
  85
  86 module_init(init_ppe_rr_module);
  87 module_exit(cleanup_ppe_rr_module);
  88
  89 MODULE_LICENSE("GPL");
  90 MODULE_AUTHOR("Daniel Borkmann <dborkma@tik.ee.ethz.ch>");
  91 MODULE_DESCRIPTION("LANA round robin scheduler");
  92