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freebsd/sys/netinet/ipfw/dn_sched_prio.c
Luigi Rizzo 3b4d8b3f7a Add a priority-based packet scheduler.
Sponsored by:	The ONELAB2 Project
Submitted by:	Riccardo Panicucci
2010-03-21 16:30:32 +00:00

230 lines
6.1 KiB
C

/*
* Copyright (c) 2010 Riccardo Panicucci, Universita` di Pisa
* All rights reserved
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* $FreeBSD$
*/
#ifdef _KERNEL
#include <sys/malloc.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/kernel.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <net/if.h> /* IFNAMSIZ */
#include <netinet/in.h>
#include <netinet/ip_var.h> /* ipfw_rule_ref */
#include <netinet/ip_fw.h> /* flow_id */
#include <netinet/ip_dummynet.h>
#include <netinet/ipfw/dn_heap.h>
#include <netinet/ipfw/ip_dn_private.h>
#include <netinet/ipfw/dn_sched.h>
#else
#include <dn_test.h>
#endif
#define DN_SCHED_PRIO 5 //XXX
#if !defined(_KERNEL) || !defined(__linux__)
#define test_bit(ix, pData) ((*pData) & (1<<(ix)))
#define __set_bit(ix, pData) (*pData) |= (1<<(ix))
#define __clear_bit(ix, pData) (*pData) &= ~(1<<(ix))
#endif
#ifdef __MIPSEL__
#define __clear_bit(ix, pData) (*pData) &= ~(1<<(ix))
#endif
/* Size of the array of queues pointers. */
#define BITMAP_T unsigned long
#define MAXPRIO (sizeof(BITMAP_T) * 8)
/*
* The scheduler instance contains an array of pointers to queues,
* one for each priority, and a bitmap listing backlogged queues.
*/
struct prio_si {
BITMAP_T bitmap; /* array bitmap */
struct dn_queue *q_array[MAXPRIO]; /* Array of queues pointers */
};
/*
* If a queue with the same priority is already backlogged, use
* that one instead of the queue passed as argument.
*/
static int
prio_enqueue(struct dn_sch_inst *_si, struct dn_queue *q, struct mbuf *m)
{
struct prio_si *si = (struct prio_si *)(_si + 1);
int prio = q->fs->fs.par[0];
if (test_bit(prio, &si->bitmap) == 0) {
/* No queue with this priority, insert */
__set_bit(prio, &si->bitmap);
si->q_array[prio] = q;
} else { /* use the existing queue */
q = si->q_array[prio];
}
if (dn_enqueue(q, m, 0))
return 1;
return 0;
}
/*
* Packets are dequeued only from the highest priority queue.
* The function ffs() return the lowest bit in the bitmap that rapresent
* the array index (-1) which contains the pointer to the highest priority
* queue.
* After the dequeue, if this queue become empty, it is index is removed
* from the bitmap.
* Scheduler is idle if the bitmap is empty
*
* NOTE: highest priority is 0, lowest is sched->max_prio_q
*/
static struct mbuf *
prio_dequeue(struct dn_sch_inst *_si)
{
struct prio_si *si = (struct prio_si *)(_si + 1);
struct mbuf *m;
struct dn_queue *q;
int prio;
if (si->bitmap == 0) /* scheduler idle */
return NULL;
prio = ffs(si->bitmap) - 1;
/* Take the highest priority queue in the scheduler */
q = si->q_array[prio];
// assert(q)
m = dn_dequeue(q);
if (q->mq.head == NULL) {
/* Queue is now empty, remove from scheduler
* and mark it
*/
si->q_array[prio] = NULL;
__clear_bit(prio, &si->bitmap);
}
return m;
}
static int
prio_new_sched(struct dn_sch_inst *_si)
{
struct prio_si *si = (struct prio_si *)(_si + 1);
bzero(si->q_array, sizeof(si->q_array));
si->bitmap = 0;
return 0;
}
static int
prio_new_fsk(struct dn_fsk *fs)
{
/* Check if the prioritiy is between 0 and MAXPRIO-1 */
ipdn_bound_var(&fs->fs.par[0], 0, 0, MAXPRIO - 1, "PRIO priority");
return 0;
}
static int
prio_new_queue(struct dn_queue *q)
{
struct prio_si *si = (struct prio_si *)(q->_si + 1);
int prio = q->fs->fs.par[0];
struct dn_queue *oldq;
q->ni.oid.subtype = DN_SCHED_PRIO;
if (q->mq.head == NULL)
return 0;
/* Queue already full, must insert in the scheduler or append
* mbufs to existing queue. This partly duplicates prio_enqueue
*/
if (test_bit(prio, &si->bitmap) == 0) {
/* No queue with this priority, insert */
__set_bit(prio, &si->bitmap);
si->q_array[prio] = q;
} else if ( (oldq = si->q_array[prio]) != q) {
/* must append to the existing queue.
* can simply append q->mq.head to q2->...
* and add the counters to those of q2
*/
oldq->mq.tail->m_nextpkt = q->mq.head;
oldq->mq.tail = q->mq.tail;
oldq->ni.length += q->ni.length;
q->ni.length = 0;
oldq->ni.len_bytes += q->ni.len_bytes;
q->ni.len_bytes = 0;
q->mq.tail = q->mq.head = NULL;
}
return 0;
}
static int
prio_free_queue(struct dn_queue *q)
{
int prio = q->fs->fs.par[0];
struct prio_si *si = (struct prio_si *)(q->_si + 1);
if (si->q_array[prio] == q) {
si->q_array[prio] = NULL;
__clear_bit(prio, &si->bitmap);
}
return 0;
}
static struct dn_alg prio_desc = {
_SI( .type = ) DN_SCHED_PRIO,
_SI( .name = ) "PRIO",
_SI( .flags = ) DN_MULTIQUEUE,
/* we need extra space in the si and the queue */
_SI( .schk_datalen = ) 0,
_SI( .si_datalen = ) sizeof(struct prio_si),
_SI( .q_datalen = ) 0,
_SI( .enqueue = ) prio_enqueue,
_SI( .dequeue = ) prio_dequeue,
_SI( .config = ) NULL,
_SI( .destroy = ) NULL,
_SI( .new_sched = ) prio_new_sched,
_SI( .free_sched = ) NULL,
_SI( .new_fsk = ) prio_new_fsk,
_SI( .free_fsk = ) NULL,
_SI( .new_queue = ) prio_new_queue,
_SI( .free_queue = ) prio_free_queue,
};
DECLARE_DNSCHED_MODULE(dn_prio, &prio_desc);