--- /dev/null
+/*
+ * Copyright (c) 2010 Riccardo Panicucci, Universita` di Pisa
+ * Copyright (c) 2000-2002 Luigi Rizzo, 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.
+ */
+
+/*
+ * $Id: dn_sched_wf2q.c 5621 2010-03-04 16:51:27Z luigi $
+ */
+
+#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
+
+#ifndef MAX64
+#define MAX64(x,y) (( (int64_t) ( (y)-(x) )) > 0 ) ? (y) : (x)
+#endif
+
+/*
+ * timestamps are computed on 64 bit using fixed point arithmetic.
+ * LMAX_BITS, WMAX_BITS are the max number of bits for the packet len
+ * and sum of weights, respectively. FRAC_BITS is the number of
+ * fractional bits. We want FRAC_BITS >> WMAX_BITS to avoid too large
+ * errors when computing the inverse, FRAC_BITS < 32 so we can do 1/w
+ * using an unsigned 32-bit division, and to avoid wraparounds we need
+ * LMAX_BITS + WMAX_BITS + FRAC_BITS << 64
+ * As an example
+ * FRAC_BITS = 26, LMAX_BITS=14, WMAX_BITS = 19
+ */
+#ifndef FRAC_BITS
+#define FRAC_BITS 28 /* shift for fixed point arithmetic */
+#define ONE_FP (1UL << FRAC_BITS)
+#endif
+
+/*
+ * Private information for the scheduler instance:
+ * sch_heap (key is Finish time) returns the next queue to serve
+ * ne_heap (key is Start time) stores not-eligible queues
+ * idle_heap (key=start/finish time) stores idle flows. It must
+ * support extract-from-middle.
+ * A flow is only in 1 of the three heaps.
+ * XXX todo: use a more efficient data structure, e.g. a tree sorted
+ * by F with min_subtree(S) in each node
+ */
+struct wf2qp_si {
+ struct dn_heap sch_heap; /* top extract - key Finish time */
+ struct dn_heap ne_heap; /* top extract - key Start time */
+ struct dn_heap idle_heap; /* random extract - key Start=Finish time */
+ uint64_t V; /* virtual time */
+ uint32_t inv_wsum; /* inverse of sum of weights */
+ uint32_t wsum; /* sum of weights */
+};
+
+struct wf2qp_queue {
+ struct dn_queue _q;
+ uint64_t S, F; /* start time, finish time */
+ uint32_t inv_w; /* ONE_FP / weight */
+ int32_t heap_pos; /* position (index) of struct in heap */
+};
+
+/*
+ * This file implements a WF2Q+ scheduler as it has been in dummynet
+ * since 2000.
+ * The scheduler supports per-flow queues and has O(log N) complexity.
+ *
+ * WF2Q+ needs to drain entries from the idle heap so that we
+ * can keep the sum of weights up to date. We can do it whenever
+ * we get a chance, or periodically, or following some other
+ * strategy. The function idle_check() drains at most N elements
+ * from the idle heap.
+ */
+static void
+idle_check(struct wf2qp_si *si, int n, int force)
+{
+ struct dn_heap *h = &si->idle_heap;
+ while (n-- > 0 && h->elements > 0 &&
+ (force || DN_KEY_LT(HEAP_TOP(h)->key, si->V))) {
+ struct dn_queue *q = HEAP_TOP(h)->object;
+ struct wf2qp_queue *alg_fq = (struct wf2qp_queue *)q;
+
+ heap_extract(h, NULL);
+ /* XXX to let the flowset delete the queue we should
+ * mark it as 'unused' by the scheduler.
+ */
+ alg_fq->S = alg_fq->F + 1; /* Mark timestamp as invalid. */
+ si->wsum -= q->fs->fs.par[0]; /* adjust sum of weights */
+ if (si->wsum > 0)
+ si->inv_wsum = ONE_FP/si->wsum;
+ }
+}
+
+static int
+wf2qp_enqueue(struct dn_sch_inst *_si, struct dn_queue *q, struct mbuf *m)
+{
+ struct dn_fsk *fs = q->fs;
+ struct wf2qp_si *si = (struct wf2qp_si *)(_si + 1);
+ struct wf2qp_queue *alg_fq;
+ uint64_t len = m->m_pkthdr.len;
+
+ if (m != q->mq.head) {
+ if (dn_enqueue(q, m, 0)) /* packet was dropped */
+ return 1;
+ if (m != q->mq.head) /* queue was already busy */
+ return 0;
+ }
+
+ /* If reach this point, queue q was idle */
+ alg_fq = (struct wf2qp_queue *)q;
+
+ if (DN_KEY_LT(alg_fq->F, alg_fq->S)) {
+ /* F<S means timestamps are invalid ->brand new queue. */
+ alg_fq->S = si->V; /* init start time */
+ si->wsum += fs->fs.par[0]; /* add weight of new queue. */
+ si->inv_wsum = ONE_FP/si->wsum;
+ } else { /* if it was idle then it was in the idle heap */
+ heap_extract(&si->idle_heap, q);
+ alg_fq->S = MAX64(alg_fq->F, si->V); /* compute new S */
+ }
+ alg_fq->F = alg_fq->S + len * alg_fq->inv_w;
+
+ /* if nothing is backlogged, make sure this flow is eligible */
+ if (si->ne_heap.elements == 0 && si->sch_heap.elements == 0)
+ si->V = MAX64(alg_fq->S, si->V);
+
+ /*
+ * Look at eligibility. A flow is not eligibile if S>V (when
+ * this happens, it means that there is some other flow already
+ * scheduled for the same pipe, so the sch_heap cannot be
+ * empty). If the flow is not eligible we just store it in the
+ * ne_heap. Otherwise, we store in the sch_heap.
+ * Note that for all flows in sch_heap (SCH), S_i <= V,
+ * and for all flows in ne_heap (NEH), S_i > V.
+ * So when we need to compute max(V, min(S_i)) forall i in
+ * SCH+NEH, we only need to look into NEH.
+ */
+ if (DN_KEY_LT(si->V, alg_fq->S)) {
+ /* S>V means flow Not eligible. */
+ if (si->sch_heap.elements == 0)
+ D("++ ouch! not eligible but empty scheduler!");
+ heap_insert(&si->ne_heap, alg_fq->S, q);
+ } else {
+ heap_insert(&si->sch_heap, alg_fq->F, q);
+ }
+ return 0;
+}
+
+/* XXX invariant: sch > 0 || V >= min(S in neh) */
+static struct mbuf *
+wf2qp_dequeue(struct dn_sch_inst *_si)
+{
+ /* Access scheduler instance private data */
+ struct wf2qp_si *si = (struct wf2qp_si *)(_si + 1);
+ struct mbuf *m;
+ struct dn_queue *q;
+ struct dn_heap *sch = &si->sch_heap;
+ struct dn_heap *neh = &si->ne_heap;
+ struct wf2qp_queue *alg_fq;
+
+ if (sch->elements == 0 && neh->elements == 0) {
+ /* we have nothing to do. We could kill the idle heap
+ * altogether and reset V
+ */
+ idle_check(si, 0x7fffffff, 1);
+ si->V = 0;
+ si->wsum = 0; /* should be set already */
+ return NULL; /* quick return if nothing to do */
+ }
+ idle_check(si, 1, 0); /* drain something from the idle heap */
+
+ /* make sure at least one element is eligible, bumping V
+ * and moving entries that have become eligible.
+ * We need to repeat the first part twice, before and
+ * after extracting the candidate, or enqueue() will
+ * find the data structure in a wrong state.
+ */
+ m = NULL;
+ for(;;) {
+ /*
+ * Compute V = max(V, min(S_i)). Remember that all elements
+ * in sch have by definition S_i <= V so if sch is not empty,
+ * V is surely the max and we must not update it. Conversely,
+ * if sch is empty we only need to look at neh.
+ * We don't need to move the queues, as it will be done at the
+ * next enqueue
+ */
+ if (sch->elements == 0 && neh->elements > 0) {
+ si->V = MAX64(si->V, HEAP_TOP(neh)->key);
+ }
+ while (neh->elements > 0 &&
+ DN_KEY_LEQ(HEAP_TOP(neh)->key, si->V)) {
+ q = HEAP_TOP(neh)->object;
+ alg_fq = (struct wf2qp_queue *)q;
+ heap_extract(neh, NULL);
+ heap_insert(sch, alg_fq->F, q);
+ }
+ if (m) /* pkt found in previous iteration */
+ break;
+ /* ok we have at least one eligible pkt */
+ q = HEAP_TOP(sch)->object;
+ alg_fq = (struct wf2qp_queue *)q;
+ m = dn_dequeue(q);
+ heap_extract(sch, NULL); /* Remove queue from heap. */
+ si->V += (uint64_t)(m->m_pkthdr.len) * si->inv_wsum;
+ alg_fq->S = alg_fq->F; /* Update start time. */
+ if (q->mq.head == 0) { /* not backlogged any more. */
+ heap_insert(&si->idle_heap, alg_fq->F, q);
+ } else { /* Still backlogged. */
+ /* Update F, store in neh or sch */
+ uint64_t len = q->mq.head->m_pkthdr.len;
+ alg_fq->F += len * alg_fq->inv_w;
+ if (DN_KEY_LEQ(alg_fq->S, si->V)) {
+ heap_insert(sch, alg_fq->F, q);
+ } else {
+ heap_insert(neh, alg_fq->S, q);
+ }
+ }
+ }
+ return m;
+}
+
+static int
+wf2qp_new_sched(struct dn_sch_inst *_si)
+{
+ struct wf2qp_si *si = (struct wf2qp_si *)(_si + 1);
+ int ofs = offsetof(struct wf2qp_queue, heap_pos);
+
+ /* all heaps support extract from middle */
+ if (heap_init(&si->idle_heap, 16, ofs) ||
+ heap_init(&si->sch_heap, 16, ofs) ||
+ heap_init(&si->ne_heap, 16, ofs)) {
+ heap_free(&si->ne_heap);
+ heap_free(&si->sch_heap);
+ heap_free(&si->idle_heap);
+ return ENOMEM;
+ }
+ return 0;
+}
+
+static int
+wf2qp_free_sched(struct dn_sch_inst *_si)
+{
+ struct wf2qp_si *si = (struct wf2qp_si *)(_si + 1);
+
+ heap_free(&si->sch_heap);
+ heap_free(&si->ne_heap);
+ heap_free(&si->idle_heap);
+
+ return 0;
+}
+
+static int
+wf2qp_new_fsk(struct dn_fsk *fs)
+{
+ ipdn_bound_var(&fs->fs.par[0], 1,
+ 1, 100, "WF2Q+ weight");
+ return 0;
+}
+
+static int
+wf2qp_new_queue(struct dn_queue *_q)
+{
+ struct wf2qp_queue *q = (struct wf2qp_queue *)_q;
+
+ _q->ni.oid.subtype = DN_SCHED_WF2QP;
+ q->F = 0; /* not strictly necessary */
+ q->S = q->F + 1; /* mark timestamp as invalid. */
+ q->inv_w = ONE_FP / _q->fs->fs.par[0];
+ if (_q->mq.head != NULL) {
+ wf2qp_enqueue(_q->_si, _q, _q->mq.head);
+ }
+ return 0;
+}
+
+/*
+ * Called when the infrastructure removes a queue (e.g. flowset
+ * is reconfigured). Nothing to do if we did not 'own' the queue,
+ * otherwise remove it from the right heap and adjust the sum
+ * of weights.
+ */
+static int
+wf2qp_free_queue(struct dn_queue *q)
+{
+ struct wf2qp_queue *alg_fq = (struct wf2qp_queue *)q;
+ struct wf2qp_si *si = (struct wf2qp_si *)(q->_si + 1);
+
+ if (alg_fq->S >= alg_fq->F + 1)
+ return 0; /* nothing to do, not in any heap */
+ si->wsum -= q->fs->fs.par[0];
+ if (si->wsum > 0)
+ si->inv_wsum = ONE_FP/si->wsum;
+
+ /* extract from the heap. XXX TODO we may need to adjust V
+ * to make sure the invariants hold.
+ */
+ if (q->mq.head == NULL) {
+ heap_extract(&si->idle_heap, q);
+ } else if (DN_KEY_LT(si->V, alg_fq->S)) {
+ heap_extract(&si->ne_heap, q);
+ } else {
+ heap_extract(&si->sch_heap, q);
+ }
+ return 0;
+}
+
+/*
+ * WF2Q+ scheduler descriptor
+ * contains the type of the scheduler, the name, the size of the
+ * structures and function pointers.
+ */
+static struct dn_alg wf2qp_desc = {
+ _SI( .type = ) DN_SCHED_WF2QP,
+ _SI( .name = ) "WF2Q+",
+ _SI( .flags = ) DN_MULTIQUEUE,
+
+ /* we need extra space in the si and the queue */
+ _SI( .schk_datalen = ) 0,
+ _SI( .si_datalen = ) sizeof(struct wf2qp_si),
+ _SI( .q_datalen = ) sizeof(struct wf2qp_queue) -
+ sizeof(struct dn_queue),
+
+ _SI( .enqueue = ) wf2qp_enqueue,
+ _SI( .dequeue = ) wf2qp_dequeue,
+
+ _SI( .config = ) NULL,
+ _SI( .destroy = ) NULL,
+ _SI( .new_sched = ) wf2qp_new_sched,
+ _SI( .free_sched = ) wf2qp_free_sched,
+
+ _SI( .new_fsk = ) wf2qp_new_fsk,
+ _SI( .free_fsk = ) NULL,
+
+ _SI( .new_queue = ) wf2qp_new_queue,
+ _SI( .free_queue = ) wf2qp_free_queue,
+};
+
+
+DECLARE_DNSCHED_MODULE(dn_wf2qp, &wf2qp_desc);
git://git.onelab.eu / ipfw.git / blobdiff