replace the hand rolled lists of mbufs in hfsc_classq with an

mbuf_list.

hfsc lists are very clever because they manage a fifo with a single
pointer by abusing the m_next pointer of the tail mbuf to point to
the head. clever but hard to read.

mbuf_lists are slightly bigger because they explicitely track the
head mbuf, but i got us that space back by inlining hfsc_classq
into hfsc_class and removing the unnecessary classq field.

ok henning@

diff --git a/sys/net/hfsc.c b/sys/net/hfsc.c
index 95eba8d..9fec9b3 100644 (file)
--- a/sys/net/hfsc.c
+++ b/sys/net/hfsc.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: hfsc.c,v 1.20 2015/04/12 14:09:40 dlg Exp $   */
+/*     $OpenBSD: hfsc.c,v 1.21 2015/04/18 11:12:33 dlg Exp $   */
 
 /*
  * Copyright (c) 2012-2013 Henning Brauer <henning@openbsd.org>
@@ -106,9 +106,8 @@ struct hfsc_runtime_sc {
 };
 
 struct hfsc_classq {
-       struct mbuf     *tail;   /* Tail of packet queue */
-       int              qlen;   /* Queue length (in number of packets) */
-       int              qlimit; /* Queue limit (in number of packets*) */
+       struct mbuf_list q;      /* Queue of packets */
+       int              qlimit; /* Queue limit */
 };
 
 /* for TAILQ based ellist and actlist implementation */
@@ -450,7 +449,7 @@ hfsc_purge(struct ifqueue *ifq)
        struct hfsc_class       *cl;
 
        for (cl = hif->hif_rootclass; cl != NULL; cl = hfsc_nextclass(cl))
-               if (cl->cl_q.qlen > 0)
+               if (ml_len(&cl->cl_q.q) > 0)
                        hfsc_purgeq(cl);
        hif->hif_ifq->ifq_len = 0;
 }
@@ -463,6 +462,9 @@ hfsc_class_create(struct hfsc_if *hif, struct hfsc_sc *rsc,
        struct hfsc_class *cl, *p;
        int i, s;
 
+       if (qlimit == 0)
+               qlimit = HFSC_DEFAULT_QLIMIT;
+
        if (hif->hif_classes >= hif->hif_allocated) {
                u_int newslots = hfsc_more_slots(hif->hif_allocated);
 
@@ -474,10 +476,8 @@ hfsc_class_create(struct hfsc_if *hif, struct hfsc_sc *rsc,
        cl = pool_get(&hfsc_class_pl, PR_WAITOK | PR_ZERO);
        cl->cl_actc = hfsc_actlist_alloc();
 
-       if (qlimit == 0)
-               qlimit = HFSC_DEFAULT_QLIMIT;
+       ml_init(&cl->cl_q.q);
        cl->cl_q.qlimit = qlimit;
-       cl->cl_q.qlen = 0;
        cl->cl_flags = flags;
 
        if (rsc != NULL && (rsc->m1 != 0 || rsc->m2 != 0)) {
@@ -570,7 +570,7 @@ hfsc_class_destroy(struct hfsc_class *cl)
 
        s = splnet();
 
-       if (cl->cl_q.qlen > 0)
+       if (ml_len(&cl->cl_q.q) > 0)
                hfsc_purgeq(cl);
 
        if (cl->cl_parent != NULL) {
@@ -664,7 +664,7 @@ hfsc_enqueue(struct ifqueue *ifq, struct mbuf *m)
        m->m_pkthdr.pf.prio = IFQ_MAXPRIO;
 
        /* successfully queued. */
-       if (cl->cl_q.qlen == 1)
+       if (ml_len(&cl->cl_q.q) == 1)
                hfsc_set_active(cl, m->m_pkthdr.len);
 
        return (0);
@@ -744,10 +744,10 @@ hfsc_dequeue(struct ifqueue *ifq, int remove)
        if (realtime)
                cl->cl_cumul += m->m_pkthdr.len;
 
-       if (cl->cl_q.qlen > 0) {
+       if (ml_len(&cl->cl_q.q) > 0) {
                if (cl->cl_rsc != NULL) {
                        /* update ed */
-                       next_len = cl->cl_q.tail->m_nextpkt->m_pkthdr.len;
+                       next_len = cl->cl_q.q.ml_head->m_pkthdr.len;
 
                        if (realtime)
                                hfsc_update_ed(cl, next_len);
@@ -780,19 +780,10 @@ hfsc_deferred(void *arg)
 int
 hfsc_addq(struct hfsc_class *cl, struct mbuf *m)
 {
-       struct mbuf *m0;
-
-       if (cl->cl_q.qlen >= cl->cl_q.qlimit)
+       if (ml_len(&cl->cl_q.q) >= cl->cl_q.qlimit)
                return (-1);
 
-       if ((m0 = cl->cl_q.tail) != NULL)
-               m->m_nextpkt = m0->m_nextpkt;
-       else
-               m0 = m;
-
-       m0->m_nextpkt = m;
-       cl->cl_q.tail = m;
-       cl->cl_q.qlen++;
+       ml_enqueue(&cl->cl_q.q, m);
 
        return (0);
 }
@@ -800,25 +791,14 @@ hfsc_addq(struct hfsc_class *cl, struct mbuf *m)
 struct mbuf *
 hfsc_getq(struct hfsc_class *cl)
 {
-       struct mbuf     *m, *m0;
-
-       if ((m = cl->cl_q.tail) == NULL)
-               return (NULL);
-       if ((m0 = m->m_nextpkt) != m)
-               m->m_nextpkt = m0->m_nextpkt;
-       else 
-               cl->cl_q.tail = NULL;
-       cl->cl_q.qlen--;
-       m0->m_nextpkt = NULL;
-       return (m0);
+       return (ml_dequeue(&cl->cl_q.q));
 }
 
 struct mbuf *
 hfsc_pollq(struct hfsc_class *cl)
 {
-       if (!cl->cl_q.tail)
-               return (NULL);
-       return (cl->cl_q.tail->m_nextpkt);
+       /* XXX */
+       return (cl->cl_q.q.ml_head);
 }
 
 void
@@ -826,7 +806,7 @@ hfsc_purgeq(struct hfsc_class *cl)
 {
        struct mbuf *m;
 
-       if (cl->cl_q.qlen == 0)
+       if (ml_empty(&cl->cl_q.q))
                return;
 
        while ((m = hfsc_getq(cl)) != NULL) {
@@ -1003,7 +983,7 @@ hfsc_update_vf(struct hfsc_class *cl, int len, u_int64_t cur_time)
        u_int64_t f, myf_bound, delta;
        int go_passive;
 
-       go_passive = (cl->cl_q.qlen == 0);
+       go_passive = ml_empty(&cl->cl_q.q);
 
        for (; cl->cl_parent != NULL; cl = cl->cl_parent) {
                cl->cl_total += len;
@@ -1599,7 +1579,7 @@ hfsc_getclstats(struct hfsc_class_stats *sp, struct hfsc_class *cl)
        sp->cur_time = hfsc_microuptime();
        sp->machclk_freq = HFSC_FREQ;
 
-       sp->qlength = cl->cl_q.qlen;
+       sp->qlength = ml_len(&cl->cl_q.q);
        sp->qlimit = cl->cl_q.qlimit;
        sp->xmit_cnt = cl->cl_stats.xmit_cnt;
        sp->drop_cnt = cl->cl_stats.drop_cnt;