dn_sched_rr.c revision 294879 
1/*
2 * Copyright (c) 2010 Riccardo Panicucci, Universita` di Pisa
3 * All rights reserved
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27/*
28 * $FreeBSD: head/sys/netpfil/ipfw/dn_sched_rr.c 294879 2016-01-27 02:08:30Z luigi $
29 */
30
31#ifdef _KERNEL
32#include <sys/malloc.h>
33#include <sys/socket.h>
34#include <sys/socketvar.h>
35#include <sys/kernel.h>
36#include <sys/mbuf.h>
37#include <sys/module.h>
38#include <net/if.h>	/* IFNAMSIZ */
39#include <netinet/in.h>
40#include <netinet/ip_var.h>		/* ipfw_rule_ref */
41#include <netinet/ip_fw.h>	/* flow_id */
42#include <netinet/ip_dummynet.h>
43#include <netpfil/ipfw/dn_heap.h>
44#include <netpfil/ipfw/ip_dn_private.h>
45#include <netpfil/ipfw/dn_sched.h>
46#else
47#include <dn_test.h>
48#endif
49
50#define DN_SCHED_RR	3 // XXX Where?
51
52struct rr_queue {
53	struct dn_queue q;		/* Standard queue */
54	int status;			/* 1: queue is in the list */
55	uint32_t credit;		/* max bytes we can transmit */
56	uint32_t quantum;		/* quantum * weight */
57	struct rr_queue *qnext;		/* */
58};
59
60/* struct rr_schk contains global config parameters
61 * and is right after dn_schk
62 */
63struct rr_schk {
64	uint32_t min_q;		/* Min quantum */
65	uint32_t max_q;		/* Max quantum */
66	uint32_t q_bytes;	/* default quantum in bytes */
67};
68
69/* per-instance round robin list, right after dn_sch_inst */
70struct rr_si {
71	struct rr_queue *head, *tail;	/* Pointer to current queue */
72};
73
74/* Append a queue to the rr list */
75static inline void
76rr_append(struct rr_queue *q, struct rr_si *si)
77{
78	q->status = 1;		/* mark as in-rr_list */
79	q->credit = q->quantum;	/* initialize credit */
80
81	/* append to the tail */
82	if (si->head == NULL)
83		si->head = q;
84	else
85		si->tail->qnext = q;
86	si->tail = q;		/* advance the tail pointer */
87	q->qnext = si->head;	/* make it circular */
88}
89
90/* Remove the head queue from circular list. */
91static inline void
92rr_remove_head(struct rr_si *si)
93{
94	if (si->head == NULL)
95		return; /* empty queue */
96	si->head->status = 0;
97
98	if (si->head == si->tail) {
99		si->head = si->tail = NULL;
100		return;
101	}
102
103	si->head = si->head->qnext;
104	si->tail->qnext = si->head;
105}
106
107/* Remove a queue from circular list.
108 * XXX see if ti can be merge with remove_queue()
109 */
110static inline void
111remove_queue_q(struct rr_queue *q, struct rr_si *si)
112{
113	struct rr_queue *prev;
114
115	if (q->status != 1)
116		return;
117	if (q == si->head) {
118		rr_remove_head(si);
119		return;
120	}
121
122	for (prev = si->head; prev; prev = prev->qnext) {
123		if (prev->qnext != q)
124			continue;
125		prev->qnext = q->qnext;
126		if (q == si->tail)
127			si->tail = prev;
128		q->status = 0;
129		break;
130	}
131}
132
133
134static inline void
135next_pointer(struct rr_si *si)
136{
137	if (si->head == NULL)
138		return; /* empty queue */
139
140	si->head = si->head->qnext;
141	si->tail = si->tail->qnext;
142}
143
144static int
145rr_enqueue(struct dn_sch_inst *_si, struct dn_queue *q, struct mbuf *m)
146{
147	struct rr_si *si;
148	struct rr_queue *rrq;
149
150	if (m != q->mq.head) {
151		if (dn_enqueue(q, m, 0)) /* packet was dropped */
152			return 1;
153		if (m != q->mq.head)
154			return 0;
155	}
156
157	/* If reach this point, queue q was idle */
158	si = (struct rr_si *)(_si + 1);
159	rrq = (struct rr_queue *)q;
160
161	if (rrq->status == 1) /* Queue is already in the queue list */
162		return 0;
163
164	/* Insert the queue in the queue list */
165	rr_append(rrq, si);
166
167	return 0;
168}
169
170static struct mbuf *
171rr_dequeue(struct dn_sch_inst *_si)
172{
173	/* Access scheduler instance private data */
174	struct rr_si *si = (struct rr_si *)(_si + 1);
175	struct rr_queue *rrq;
176	uint64_t len;
177
178	while ( (rrq = si->head) ) {
179		struct mbuf *m = rrq->q.mq.head;
180		if ( m == NULL) {
181			/* empty queue, remove from list */
182			rr_remove_head(si);
183			continue;
184		}
185		len = m->m_pkthdr.len;
186
187		if (len > rrq->credit) {
188			/* Packet too big */
189			rrq->credit += rrq->quantum;
190			/* Try next queue */
191			next_pointer(si);
192		} else {
193			rrq->credit -= len;
194			return dn_dequeue(&rrq->q);
195		}
196	}
197
198	/* no packet to dequeue*/
199	return NULL;
200}
201
202static int
203rr_config(struct dn_schk *_schk)
204{
205	struct rr_schk *schk = (struct rr_schk *)(_schk + 1);
206	ND("called");
207
208	/* use reasonable quantums (64..2k bytes, default 1500) */
209	schk->min_q = 64;
210	schk->max_q = 2048;
211	schk->q_bytes = 1500;	/* quantum */
212
213	return 0;
214}
215
216static int
217rr_new_sched(struct dn_sch_inst *_si)
218{
219	struct rr_si *si = (struct rr_si *)(_si + 1);
220
221	ND("called");
222	si->head = si->tail = NULL;
223
224	return 0;
225}
226
227static int
228rr_free_sched(struct dn_sch_inst *_si)
229{
230	(void)_si;
231	ND("called");
232	/* Nothing to do? */
233	return 0;
234}
235
236static int
237rr_new_fsk(struct dn_fsk *fs)
238{
239	struct rr_schk *schk = (struct rr_schk *)(fs->sched + 1);
240	/* par[0] is the weight, par[1] is the quantum step */
241	/* make sure the product fits an uint32_t */
242	ipdn_bound_var(&fs->fs.par[0], 1,
243		1, 65536, "RR weight");
244	ipdn_bound_var(&fs->fs.par[1], schk->q_bytes,
245		schk->min_q, schk->max_q, "RR quantum");
246	return 0;
247}
248
249static int
250rr_new_queue(struct dn_queue *_q)
251{
252	struct rr_queue *q = (struct rr_queue *)_q;
253	uint64_t quantum;
254
255	_q->ni.oid.subtype = DN_SCHED_RR;
256
257	quantum = (uint64_t)_q->fs->fs.par[0] * _q->fs->fs.par[1];
258	if (quantum >= (1ULL<< 32)) {
259		D("quantum too large, truncating to 4G - 1");
260		quantum = (1ULL<< 32) - 1;
261	}
262	q->quantum = quantum;
263	ND("called, q->quantum %d", q->quantum);
264	q->credit = q->quantum;
265	q->status = 0;
266
267	if (_q->mq.head != NULL) {
268		/* Queue NOT empty, insert in the queue list */
269		rr_append(q, (struct rr_si *)(_q->_si + 1));
270	}
271	return 0;
272}
273
274static int
275rr_free_queue(struct dn_queue *_q)
276{
277	struct rr_queue *q = (struct rr_queue *)_q;
278
279	ND("called");
280	if (q->status == 1) {
281		struct rr_si *si = (struct rr_si *)(_q->_si + 1);
282		remove_queue_q(q, si);
283	}
284	return 0;
285}
286
287/*
288 * RR scheduler descriptor
289 * contains the type of the scheduler, the name, the size of the
290 * structures and function pointers.
291 */
292static struct dn_alg rr_desc = {
293	_SI( .type = ) DN_SCHED_RR,
294	_SI( .name = ) "RR",
295	_SI( .flags = ) DN_MULTIQUEUE,
296
297	_SI( .schk_datalen = ) sizeof(struct rr_schk),
298	_SI( .si_datalen = ) sizeof(struct rr_si),
299	_SI( .q_datalen = ) sizeof(struct rr_queue) - sizeof(struct dn_queue),
300
301	_SI( .enqueue = ) rr_enqueue,
302	_SI( .dequeue = ) rr_dequeue,
303
304	_SI( .config = ) rr_config,
305	_SI( .destroy = ) NULL,
306	_SI( .new_sched = ) rr_new_sched,
307	_SI( .free_sched = ) rr_free_sched,
308	_SI( .new_fsk = ) rr_new_fsk,
309	_SI( .free_fsk = ) NULL,
310	_SI( .new_queue = ) rr_new_queue,
311	_SI( .free_queue = ) rr_free_queue,
312};
313
314_Static_assert(sizeof(struct dn_schk) < 193, "a");
315
316DECLARE_DNSCHED_MODULE(dn_rr, &rr_desc);
317