/*- * Copyright (c) 1997-1999 Carnegie Mellon University. All Rights Reserved. * * Permission to use, copy, modify, and distribute this software and * its documentation is hereby granted (including for commercial or * for-profit use), provided that both the copyright notice and this * permission notice appear in all copies of the software, derivative * works, or modified versions, and any portions thereof. * * THIS SOFTWARE IS EXPERIMENTAL AND IS KNOWN TO HAVE BUGS, SOME OF * WHICH MAY HAVE SERIOUS CONSEQUENCES. CARNEGIE MELLON PROVIDES THIS * SOFTWARE IN ITS ``AS IS'' CONDITION, 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 CARNEGIE MELLON UNIVERSITY 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. * * Carnegie Mellon encourages (but does not require) users of this * software to return any improvements or extensions that they make, * and to grant Carnegie Mellon the rights to redistribute these * changes without encumbrance. * * $KAME: altq_hfsc.c,v 1.24 2003/12/05 05:40:46 kjc Exp $ * $FreeBSD$ */ /* * H-FSC is described in Proceedings of SIGCOMM'97, * "A Hierarchical Fair Service Curve Algorithm for Link-Sharing, * Real-Time and Priority Service" * by Ion Stoica, Hui Zhang, and T. S. Eugene Ng. * * Oleg Cherevko added the upperlimit for link-sharing. * when a class has an upperlimit, the fit-time is computed from the * upperlimit service curve. the link-sharing scheduler does not schedule * a class whose fit-time exceeds the current time. */ #include "opt_altq.h" #include "opt_inet.h" #include "opt_inet6.h" #ifdef ALTQ_HFSC /* hfsc is enabled by ALTQ_HFSC option in opt_altq.h */ #include #include #include #include #include #include #include #if 1 /* ALTQ3_COMPAT */ #include #include #include #endif /* ALTQ3_COMPAT */ #include #include #include #include #include #include #include #include /* * function prototypes */ static int hfsc_clear_interface(struct hfsc_if *); static int hfsc_request(struct ifaltq *, int, void *); static void hfsc_purge(struct hfsc_if *); static struct hfsc_class *hfsc_class_create(struct hfsc_if *, struct service_curve *, struct service_curve *, struct service_curve *, struct hfsc_class *, int, int, int); static int hfsc_class_destroy(struct hfsc_class *); static struct hfsc_class *hfsc_nextclass(struct hfsc_class *); static int hfsc_enqueue(struct ifaltq *, struct mbuf *, struct altq_pktattr *); static struct mbuf *hfsc_dequeue(struct ifaltq *, int); static int hfsc_addq(struct hfsc_class *, struct mbuf *); static struct mbuf *hfsc_getq(struct hfsc_class *); static struct mbuf *hfsc_pollq(struct hfsc_class *); static void hfsc_purgeq(struct hfsc_class *); static void update_cfmin(struct hfsc_class *); static void set_active(struct hfsc_class *, int); static void set_passive(struct hfsc_class *); static void init_ed(struct hfsc_class *, int); static void update_ed(struct hfsc_class *, int); static void update_d(struct hfsc_class *, int); static void init_vf(struct hfsc_class *, int); static void update_vf(struct hfsc_class *, int, u_int64_t); static void ellist_insert(struct hfsc_class *); static void ellist_remove(struct hfsc_class *); static void ellist_update(struct hfsc_class *); struct hfsc_class *hfsc_get_mindl(struct hfsc_if *, u_int64_t); static void actlist_insert(struct hfsc_class *); static void actlist_remove(struct hfsc_class *); static void actlist_update(struct hfsc_class *); static struct hfsc_class *actlist_firstfit(struct hfsc_class *, u_int64_t); static __inline u_int64_t seg_x2y(u_int64_t, u_int64_t); static __inline u_int64_t seg_y2x(u_int64_t, u_int64_t); static __inline u_int64_t m2sm(u_int64_t); static __inline u_int64_t m2ism(u_int64_t); static __inline u_int64_t d2dx(u_int); static u_int64_t sm2m(u_int64_t); static u_int dx2d(u_int64_t); static void sc2isc(struct service_curve *, struct internal_sc *); static void rtsc_init(struct runtime_sc *, struct internal_sc *, u_int64_t, u_int64_t); static u_int64_t rtsc_y2x(struct runtime_sc *, u_int64_t); static u_int64_t rtsc_x2y(struct runtime_sc *, u_int64_t); static void rtsc_min(struct runtime_sc *, struct internal_sc *, u_int64_t, u_int64_t); static void get_class_stats_v0(struct hfsc_classstats_v0 *, struct hfsc_class *); static void get_class_stats_v1(struct hfsc_classstats_v1 *, struct hfsc_class *); static struct hfsc_class *clh_to_clp(struct hfsc_if *, u_int32_t); /* * macros */ #define is_a_parent_class(cl) ((cl)->cl_children != NULL) #define HT_INFINITY 0xffffffffffffffffULL /* infinite time value */ int hfsc_pfattach(struct pf_altq *a) { struct ifnet *ifp; int s, error; if ((ifp = ifunit(a->ifname)) == NULL || a->altq_disc == NULL) return (EINVAL); s = splnet(); error = altq_attach(&ifp->if_snd, ALTQT_HFSC, a->altq_disc, hfsc_enqueue, hfsc_dequeue, hfsc_request, NULL, NULL); splx(s); return (error); } int hfsc_add_altq(struct pf_altq *a) { struct hfsc_if *hif; struct ifnet *ifp; if ((ifp = ifunit(a->ifname)) == NULL) return (EINVAL); if (!ALTQ_IS_READY(&ifp->if_snd)) return (ENODEV); hif = malloc(sizeof(struct hfsc_if), M_DEVBUF, M_NOWAIT | M_ZERO); if (hif == NULL) return (ENOMEM); TAILQ_INIT(&hif->hif_eligible); hif->hif_ifq = &ifp->if_snd; /* keep the state in pf_altq */ a->altq_disc = hif; return (0); } int hfsc_remove_altq(struct pf_altq *a) { struct hfsc_if *hif; if ((hif = a->altq_disc) == NULL) return (EINVAL); a->altq_disc = NULL; (void)hfsc_clear_interface(hif); (void)hfsc_class_destroy(hif->hif_rootclass); free(hif, M_DEVBUF); return (0); } int hfsc_add_queue(struct pf_altq *a) { struct hfsc_if *hif; struct hfsc_class *cl, *parent; struct hfsc_opts_v1 *opts; struct service_curve rtsc, lssc, ulsc; if ((hif = a->altq_disc) == NULL) return (EINVAL); opts = &a->pq_u.hfsc_opts; if (a->parent_qid == HFSC_NULLCLASS_HANDLE && hif->hif_rootclass == NULL) parent = NULL; else if ((parent = clh_to_clp(hif, a->parent_qid)) == NULL) return (EINVAL); if (a->qid == 0) return (EINVAL); if (clh_to_clp(hif, a->qid) != NULL) return (EBUSY); rtsc.m1 = opts->rtsc_m1; rtsc.d = opts->rtsc_d; rtsc.m2 = opts->rtsc_m2; lssc.m1 = opts->lssc_m1; lssc.d = opts->lssc_d; lssc.m2 = opts->lssc_m2; ulsc.m1 = opts->ulsc_m1; ulsc.d = opts->ulsc_d; ulsc.m2 = opts->ulsc_m2; cl = hfsc_class_create(hif, &rtsc, &lssc, &ulsc, parent, a->qlimit, opts->flags, a->qid); if (cl == NULL) return (ENOMEM); return (0); } int hfsc_remove_queue(struct pf_altq *a) { struct hfsc_if *hif; struct hfsc_class *cl; if ((hif = a->altq_disc) == NULL) return (EINVAL); if ((cl = clh_to_clp(hif, a->qid)) == NULL) return (EINVAL); return (hfsc_class_destroy(cl)); } int hfsc_getqstats(struct pf_altq *a, void *ubuf, int *nbytes, int version) { struct hfsc_if *hif; struct hfsc_class *cl; union { struct hfsc_classstats_v0 v0; struct hfsc_classstats_v1 v1; } stats; size_t stats_size; int error = 0; if ((hif = altq_lookup(a->ifname, ALTQT_HFSC)) == NULL) return (EBADF); if ((cl = clh_to_clp(hif, a->qid)) == NULL) return (EINVAL); if (version > HFSC_STATS_VERSION) return (EINVAL); memset(&stats, 0, sizeof(stats)); switch (version) { case 0: get_class_stats_v0(&stats.v0, cl); stats_size = sizeof(struct hfsc_classstats_v0); break; case 1: get_class_stats_v1(&stats.v1, cl); stats_size = sizeof(struct hfsc_classstats_v1); break; } if (*nbytes < stats_size) return (EINVAL); if ((error = copyout((caddr_t)&stats, ubuf, stats_size)) != 0) return (error); *nbytes = stats_size; return (0); } /* * bring the interface back to the initial state by discarding * all the filters and classes except the root class. */ static int hfsc_clear_interface(struct hfsc_if *hif) { struct hfsc_class *cl; /* clear out the classes */ while (hif->hif_rootclass != NULL && (cl = hif->hif_rootclass->cl_children) != NULL) { /* * remove the first leaf class found in the hierarchy * then start over */ for (; cl != NULL; cl = hfsc_nextclass(cl)) { if (!is_a_parent_class(cl)) { (void)hfsc_class_destroy(cl); break; } } } return (0); } static int hfsc_request(struct ifaltq *ifq, int req, void *arg) { struct hfsc_if *hif = (struct hfsc_if *)ifq->altq_disc; IFQ_LOCK_ASSERT(ifq); switch (req) { case ALTRQ_PURGE: hfsc_purge(hif); break; } return (0); } /* discard all the queued packets on the interface */ static void hfsc_purge(struct hfsc_if *hif) { struct hfsc_class *cl; for (cl = hif->hif_rootclass; cl != NULL; cl = hfsc_nextclass(cl)) if (!qempty(cl->cl_q)) hfsc_purgeq(cl); if (ALTQ_IS_ENABLED(hif->hif_ifq)) hif->hif_ifq->ifq_len = 0; } struct hfsc_class * hfsc_class_create(struct hfsc_if *hif, struct service_curve *rsc, struct service_curve *fsc, struct service_curve *usc, struct hfsc_class *parent, int qlimit, int flags, int qid) { struct hfsc_class *cl, *p; int i, s; if (hif->hif_classes >= HFSC_MAX_CLASSES) return (NULL); #ifndef ALTQ_RED if (flags & HFCF_RED) { #ifdef ALTQ_DEBUG printf("hfsc_class_create: RED not configured for HFSC!\n"); #endif return (NULL); } #endif #ifndef ALTQ_CODEL if (flags & HFCF_CODEL) { #ifdef ALTQ_DEBUG printf("hfsc_class_create: CODEL not configured for HFSC!\n"); #endif return (NULL); } #endif cl = malloc(sizeof(struct hfsc_class), M_DEVBUF, M_NOWAIT | M_ZERO); if (cl == NULL) return (NULL); cl->cl_q = malloc(sizeof(class_queue_t), M_DEVBUF, M_NOWAIT | M_ZERO); if (cl->cl_q == NULL) goto err_ret; TAILQ_INIT(&cl->cl_actc); if (qlimit == 0) qlimit = 50; /* use default */ qlimit(cl->cl_q) = qlimit; qtype(cl->cl_q) = Q_DROPTAIL; qlen(cl->cl_q) = 0; qsize(cl->cl_q) = 0; cl->cl_flags = flags; #ifdef ALTQ_RED if (flags & (HFCF_RED|HFCF_RIO)) { int red_flags, red_pkttime; u_int m2; m2 = 0; if (rsc != NULL && rsc->m2 > m2) m2 = rsc->m2; if (fsc != NULL && fsc->m2 > m2) m2 = fsc->m2; if (usc != NULL && usc->m2 > m2) m2 = usc->m2; red_flags = 0; if (flags & HFCF_ECN) red_flags |= REDF_ECN; #ifdef ALTQ_RIO if (flags & HFCF_CLEARDSCP) red_flags |= RIOF_CLEARDSCP; #endif if (m2 < 8) red_pkttime = 1000 * 1000 * 1000; /* 1 sec */ else red_pkttime = (int64_t)hif->hif_ifq->altq_ifp->if_mtu * 1000 * 1000 * 1000 / (m2 / 8); if (flags & HFCF_RED) { cl->cl_red = red_alloc(0, 0, qlimit(cl->cl_q) * 10/100, qlimit(cl->cl_q) * 30/100, red_flags, red_pkttime); if (cl->cl_red != NULL) qtype(cl->cl_q) = Q_RED; } #ifdef ALTQ_RIO else { cl->cl_red = (red_t *)rio_alloc(0, NULL, red_flags, red_pkttime); if (cl->cl_red != NULL) qtype(cl->cl_q) = Q_RIO; } #endif } #endif /* ALTQ_RED */ #ifdef ALTQ_CODEL if (flags & HFCF_CODEL) { cl->cl_codel = codel_alloc(5, 100, 0); if (cl->cl_codel != NULL) qtype(cl->cl_q) = Q_CODEL; } #endif if (rsc != NULL && (rsc->m1 != 0 || rsc->m2 != 0)) { cl->cl_rsc = malloc(sizeof(struct internal_sc), M_DEVBUF, M_NOWAIT); if (cl->cl_rsc == NULL) goto err_ret; sc2isc(rsc, cl->cl_rsc); rtsc_init(&cl->cl_deadline, cl->cl_rsc, 0, 0); rtsc_init(&cl->cl_eligible, cl->cl_rsc, 0, 0); } if (fsc != NULL && (fsc->m1 != 0 || fsc->m2 != 0)) { cl->cl_fsc = malloc(sizeof(struct internal_sc), M_DEVBUF, M_NOWAIT); if (cl->cl_fsc == NULL) goto err_ret; sc2isc(fsc, cl->cl_fsc); rtsc_init(&cl->cl_virtual, cl->cl_fsc, 0, 0); } if (usc != NULL && (usc->m1 != 0 || usc->m2 != 0)) { cl->cl_usc = malloc(sizeof(struct internal_sc), M_DEVBUF, M_NOWAIT); if (cl->cl_usc == NULL) goto err_ret; sc2isc(usc, cl->cl_usc); rtsc_init(&cl->cl_ulimit, cl->cl_usc, 0, 0); } cl->cl_id = hif->hif_classid++; cl->cl_handle = qid; cl->cl_hif = hif; cl->cl_parent = parent; s = splnet(); IFQ_LOCK(hif->hif_ifq); hif->hif_classes++; /* * find a free slot in the class table. if the slot matching * the lower bits of qid is free, use this slot. otherwise, * use the first free slot. */ i = qid % HFSC_MAX_CLASSES; if (hif->hif_class_tbl[i] == NULL) hif->hif_class_tbl[i] = cl; else { for (i = 0; i < HFSC_MAX_CLASSES; i++) if (hif->hif_class_tbl[i] == NULL) { hif->hif_class_tbl[i] = cl; break; } if (i == HFSC_MAX_CLASSES) { IFQ_UNLOCK(hif->hif_ifq); splx(s); goto err_ret; } } if (flags & HFCF_DEFAULTCLASS) hif->hif_defaultclass = cl; if (parent == NULL) { /* this is root class */ hif->hif_rootclass = cl; } else { /* add this class to the children list of the parent */ if ((p = parent->cl_children) == NULL) parent->cl_children = cl; else { while (p->cl_siblings != NULL) p = p->cl_siblings; p->cl_siblings = cl; } } IFQ_UNLOCK(hif->hif_ifq); splx(s); return (cl); err_ret: if (cl->cl_red != NULL) { #ifdef ALTQ_RIO if (q_is_rio(cl->cl_q)) rio_destroy((rio_t *)cl->cl_red); #endif #ifdef ALTQ_RED if (q_is_red(cl->cl_q)) red_destroy(cl->cl_red); #endif #ifdef ALTQ_CODEL if (q_is_codel(cl->cl_q)) codel_destroy(cl->cl_codel); #endif } if (cl->cl_fsc != NULL) free(cl->cl_fsc, M_DEVBUF); if (cl->cl_rsc != NULL) free(cl->cl_rsc, M_DEVBUF); if (cl->cl_usc != NULL) free(cl->cl_usc, M_DEVBUF); if (cl->cl_q != NULL) free(cl->cl_q, M_DEVBUF); free(cl, M_DEVBUF); return (NULL); } static int hfsc_class_destroy(struct hfsc_class *cl) { int i, s; if (cl == NULL) return (0); if (is_a_parent_class(cl)) return (EBUSY); s = splnet(); IFQ_LOCK(cl->cl_hif->hif_ifq); if (!qempty(cl->cl_q)) hfsc_purgeq(cl); if (cl->cl_parent == NULL) { /* this is root class */ } else { struct hfsc_class *p = cl->cl_parent->cl_children; if (p == cl) cl->cl_parent->cl_children = cl->cl_siblings; else do { if (p->cl_siblings == cl) { p->cl_siblings = cl->cl_siblings; break; } } while ((p = p->cl_siblings) != NULL); ASSERT(p != NULL); } for (i = 0; i < HFSC_MAX_CLASSES; i++) if (cl->cl_hif->hif_class_tbl[i] == cl) { cl->cl_hif->hif_class_tbl[i] = NULL; break; } cl->cl_hif->hif_classes--; IFQ_UNLOCK(cl->cl_hif->hif_ifq); splx(s); if (cl->cl_red != NULL) { #ifdef ALTQ_RIO if (q_is_rio(cl->cl_q)) rio_destroy((rio_t *)cl->cl_red); #endif #ifdef ALTQ_RED if (q_is_red(cl->cl_q)) red_destroy(cl->cl_red); #endif #ifdef ALTQ_CODEL if (q_is_codel(cl->cl_q)) codel_destroy(cl->cl_codel); #endif } IFQ_LOCK(cl->cl_hif->hif_ifq); if (cl == cl->cl_hif->hif_rootclass) cl->cl_hif->hif_rootclass = NULL; if (cl == cl->cl_hif->hif_defaultclass) cl->cl_hif->hif_defaultclass = NULL; IFQ_UNLOCK(cl->cl_hif->hif_ifq); if (cl->cl_usc != NULL) free(cl->cl_usc, M_DEVBUF); if (cl->cl_fsc != NULL) free(cl->cl_fsc, M_DEVBUF); if (cl->cl_rsc != NULL) free(cl->cl_rsc, M_DEVBUF); free(cl->cl_q, M_DEVBUF); free(cl, M_DEVBUF); return (0); } /* * hfsc_nextclass returns the next class in the tree. * usage: * for (cl = hif->hif_rootclass; cl != NULL; cl = hfsc_nextclass(cl)) * do_something; */ static struct hfsc_class * hfsc_nextclass(struct hfsc_class *cl) { if (cl->cl_children != NULL) cl = cl->cl_children; else if (cl->cl_siblings != NULL) cl = cl->cl_siblings; else { while ((cl = cl->cl_parent) != NULL) if (cl->cl_siblings) { cl = cl->cl_siblings; break; } } return (cl); } /* * hfsc_enqueue is an enqueue function to be registered to * (*altq_enqueue) in struct ifaltq. */ static int hfsc_enqueue(struct ifaltq *ifq, struct mbuf *m, struct altq_pktattr *pktattr) { struct hfsc_if *hif = (struct hfsc_if *)ifq->altq_disc; struct hfsc_class *cl; struct pf_mtag *t; int len; IFQ_LOCK_ASSERT(ifq); /* grab class set by classifier */ if ((m->m_flags & M_PKTHDR) == 0) { /* should not happen */ printf("altq: packet for %s does not have pkthdr\n", ifq->altq_ifp->if_xname); m_freem(m); return (ENOBUFS); } cl = NULL; if ((t = pf_find_mtag(m)) != NULL) cl = clh_to_clp(hif, t->qid); if (cl == NULL || is_a_parent_class(cl)) { cl = hif->hif_defaultclass; if (cl == NULL) { m_freem(m); return (ENOBUFS); } } cl->cl_pktattr = NULL; len = m_pktlen(m); if (hfsc_addq(cl, m) != 0) { /* drop occurred. mbuf was freed in hfsc_addq. */ PKTCNTR_ADD(&cl->cl_stats.drop_cnt, len); return (ENOBUFS); } IFQ_INC_LEN(ifq); cl->cl_hif->hif_packets++; /* successfully queued. */ if (qlen(cl->cl_q) == 1) set_active(cl, m_pktlen(m)); return (0); } /* * hfsc_dequeue is a dequeue function to be registered to * (*altq_dequeue) in struct ifaltq. * * note: ALTDQ_POLL returns the next packet without removing the packet * from the queue. ALTDQ_REMOVE is a normal dequeue operation. * ALTDQ_REMOVE must return the same packet if called immediately * after ALTDQ_POLL. */ static struct mbuf * hfsc_dequeue(struct ifaltq *ifq, int op) { struct hfsc_if *hif = (struct hfsc_if *)ifq->altq_disc; struct hfsc_class *cl; struct mbuf *m; int len, next_len; int realtime = 0; u_int64_t cur_time; IFQ_LOCK_ASSERT(ifq); if (hif->hif_packets == 0) /* no packet in the tree */ return (NULL); cur_time = read_machclk(); if (op == ALTDQ_REMOVE && hif->hif_pollcache != NULL) { cl = hif->hif_pollcache; hif->hif_pollcache = NULL; /* check if the class was scheduled by real-time criteria */ if (cl->cl_rsc != NULL) realtime = (cl->cl_e <= cur_time); } else { /* * if there are eligible classes, use real-time criteria. * find the class with the minimum deadline among * the eligible classes. */ if ((cl = hfsc_get_mindl(hif, cur_time)) != NULL) { realtime = 1; } else { #ifdef ALTQ_DEBUG int fits = 0; #endif /* * use link-sharing criteria * get the class with the minimum vt in the hierarchy */ cl = hif->hif_rootclass; while (is_a_parent_class(cl)) { cl = actlist_firstfit(cl, cur_time); if (cl == NULL) { #ifdef ALTQ_DEBUG if (fits > 0) printf("%d fit but none found\n",fits); #endif return (NULL); } /* * update parent's cl_cvtmin. * don't update if the new vt is smaller. */ if (cl->cl_parent->cl_cvtmin < cl->cl_vt) cl->cl_parent->cl_cvtmin = cl->cl_vt; #ifdef ALTQ_DEBUG fits++; #endif } } if (op == ALTDQ_POLL) { hif->hif_pollcache = cl; m = hfsc_pollq(cl); return (m); } } m = hfsc_getq(cl); if (m == NULL) panic("hfsc_dequeue:"); len = m_pktlen(m); cl->cl_hif->hif_packets--; IFQ_DEC_LEN(ifq); PKTCNTR_ADD(&cl->cl_stats.xmit_cnt, len); update_vf(cl, len, cur_time); if (realtime) cl->cl_cumul += len; if (!qempty(cl->cl_q)) { if (cl->cl_rsc != NULL) { /* update ed */ next_len = m_pktlen(qhead(cl->cl_q)); if (realtime) update_ed(cl, next_len); else update_d(cl, next_len); } } else { /* the class becomes passive */ set_passive(cl); } return (m); } static int hfsc_addq(struct hfsc_class *cl, struct mbuf *m) { #ifdef ALTQ_RIO if (q_is_rio(cl->cl_q)) return rio_addq((rio_t *)cl->cl_red, cl->cl_q, m, cl->cl_pktattr); #endif #ifdef ALTQ_RED if (q_is_red(cl->cl_q)) return red_addq(cl->cl_red, cl->cl_q, m, cl->cl_pktattr); #endif #ifdef ALTQ_CODEL if (q_is_codel(cl->cl_q)) return codel_addq(cl->cl_codel, cl->cl_q, m); #endif if (qlen(cl->cl_q) >= qlimit(cl->cl_q)) { m_freem(m); return (-1); } if (cl->cl_flags & HFCF_CLEARDSCP) write_dsfield(m, cl->cl_pktattr, 0); _addq(cl->cl_q, m); return (0); } static struct mbuf * hfsc_getq(struct hfsc_class *cl) { #ifdef ALTQ_RIO if (q_is_rio(cl->cl_q)) return rio_getq((rio_t *)cl->cl_red, cl->cl_q); #endif #ifdef ALTQ_RED if (q_is_red(cl->cl_q)) return red_getq(cl->cl_red, cl->cl_q); #endif #ifdef ALTQ_CODEL if (q_is_codel(cl->cl_q)) return codel_getq(cl->cl_codel, cl->cl_q); #endif return _getq(cl->cl_q); } static struct mbuf * hfsc_pollq(struct hfsc_class *cl) { return qhead(cl->cl_q); } static void hfsc_purgeq(struct hfsc_class *cl) { struct mbuf *m; if (qempty(cl->cl_q)) return; while ((m = _getq(cl->cl_q)) != NULL) { PKTCNTR_ADD(&cl->cl_stats.drop_cnt, m_pktlen(m)); m_freem(m); cl->cl_hif->hif_packets--; IFQ_DEC_LEN(cl->cl_hif->hif_ifq); } ASSERT(qlen(cl->cl_q) == 0); update_vf(cl, 0, 0); /* remove cl from the actlist */ set_passive(cl); } static void set_active(struct hfsc_class *cl, int len) { if (cl->cl_rsc != NULL) init_ed(cl, len); if (cl->cl_fsc != NULL) init_vf(cl, len); cl->cl_stats.period++; } static void set_passive(struct hfsc_class *cl) { if (cl->cl_rsc != NULL) ellist_remove(cl); /* * actlist is now handled in update_vf() so that update_vf(cl, 0, 0) * needs to be called explicitly to remove a class from actlist */ } static void init_ed(struct hfsc_class *cl, int next_len) { u_int64_t cur_time; cur_time = read_machclk(); /* update the deadline curve */ rtsc_min(&cl->cl_deadline, cl->cl_rsc, cur_time, cl->cl_cumul); /* * update the eligible curve. * for concave, it is equal to the deadline curve. * for convex, it is a linear curve with slope m2. */ cl->cl_eligible = cl->cl_deadline; if (cl->cl_rsc->sm1 <= cl->cl_rsc->sm2) { cl->cl_eligible.dx = 0; cl->cl_eligible.dy = 0; } /* compute e and d */ cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul); cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len); ellist_insert(cl); } static void update_ed(struct hfsc_class *cl, int next_len) { cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul); cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len); ellist_update(cl); } static void update_d(struct hfsc_class *cl, int next_len) { cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len); } static void init_vf(struct hfsc_class *cl, int len) { struct hfsc_class *max_cl, *p; u_int64_t vt, f, cur_time; int go_active; cur_time = 0; go_active = 1; for ( ; cl->cl_parent != NULL; cl = cl->cl_parent) { if (go_active && cl->cl_nactive++ == 0) go_active = 1; else go_active = 0; if (go_active) { max_cl = TAILQ_LAST(&cl->cl_parent->cl_actc, acthead); if (max_cl != NULL) { /* * set vt to the average of the min and max * classes. if the parent's period didn't * change, don't decrease vt of the class. */ vt = max_cl->cl_vt; if (cl->cl_parent->cl_cvtmin != 0) vt = (cl->cl_parent->cl_cvtmin + vt)/2; if (cl->cl_parent->cl_vtperiod != cl->cl_parentperiod || vt > cl->cl_vt) cl->cl_vt = vt; } else { /* * first child for a new parent backlog period. * add parent's cvtmax to vtoff of children * to make a new vt (vtoff + vt) larger than * the vt in the last period for all children. */ vt = cl->cl_parent->cl_cvtmax; for (p = cl->cl_parent->cl_children; p != NULL; p = p->cl_siblings) p->cl_vtoff += vt; cl->cl_vt = 0; cl->cl_parent->cl_cvtmax = 0; cl->cl_parent->cl_cvtmin = 0; } cl->cl_initvt = cl->cl_vt; /* update the virtual curve */ vt = cl->cl_vt + cl->cl_vtoff; rtsc_min(&cl->cl_virtual, cl->cl_fsc, vt, cl->cl_total); if (cl->cl_virtual.x == vt) { cl->cl_virtual.x -= cl->cl_vtoff; cl->cl_vtoff = 0; } cl->cl_vtadj = 0; cl->cl_vtperiod++; /* increment vt period */ cl->cl_parentperiod = cl->cl_parent->cl_vtperiod; if (cl->cl_parent->cl_nactive == 0) cl->cl_parentperiod++; cl->cl_f = 0; actlist_insert(cl); if (cl->cl_usc != NULL) { /* class has upper limit curve */ if (cur_time == 0) cur_time = read_machclk(); /* update the ulimit curve */ rtsc_min(&cl->cl_ulimit, cl->cl_usc, cur_time, cl->cl_total); /* compute myf */ cl->cl_myf = rtsc_y2x(&cl->cl_ulimit, cl->cl_total); cl->cl_myfadj = 0; } } if (cl->cl_myf > cl->cl_cfmin) f = cl->cl_myf; else f = cl->cl_cfmin; if (f != cl->cl_f) { cl->cl_f = f; update_cfmin(cl->cl_parent); } } } static void 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 = qempty(cl->cl_q); for (; cl->cl_parent != NULL; cl = cl->cl_parent) { cl->cl_total += len; if (cl->cl_fsc == NULL || cl->cl_nactive == 0) continue; if (go_passive && --cl->cl_nactive == 0) go_passive = 1; else go_passive = 0; if (go_passive) { /* no more active child, going passive */ /* update cvtmax of the parent class */ if (cl->cl_vt > cl->cl_parent->cl_cvtmax) cl->cl_parent->cl_cvtmax = cl->cl_vt; /* remove this class from the vt list */ actlist_remove(cl); update_cfmin(cl->cl_parent); continue; } /* * update vt and f */ cl->cl_vt = rtsc_y2x(&cl->cl_virtual, cl->cl_total) - cl->cl_vtoff + cl->cl_vtadj; /* * if vt of the class is smaller than cvtmin, * the class was skipped in the past due to non-fit. * if so, we need to adjust vtadj. */ if (cl->cl_vt < cl->cl_parent->cl_cvtmin) { cl->cl_vtadj += cl->cl_parent->cl_cvtmin - cl->cl_vt; cl->cl_vt = cl->cl_parent->cl_cvtmin; } /* update the vt list */ actlist_update(cl); if (cl->cl_usc != NULL) { cl->cl_myf = cl->cl_myfadj + rtsc_y2x(&cl->cl_ulimit, cl->cl_total); /* * if myf lags behind by more than one clock tick * from the current time, adjust myfadj to prevent * a rate-limited class from going greedy. * in a steady state under rate-limiting, myf * fluctuates within one clock tick. */ myf_bound = cur_time - machclk_per_tick; if (cl->cl_myf < myf_bound) { delta = cur_time - cl->cl_myf; cl->cl_myfadj += delta; cl->cl_myf += delta; } } /* cl_f is max(cl_myf, cl_cfmin) */ if (cl->cl_myf > cl->cl_cfmin) f = cl->cl_myf; else f = cl->cl_cfmin; if (f != cl->cl_f) { cl->cl_f = f; update_cfmin(cl->cl_parent); } } } static void update_cfmin(struct hfsc_class *cl) { struct hfsc_class *p; u_int64_t cfmin; if (TAILQ_EMPTY(&cl->cl_actc)) { cl->cl_cfmin = 0; return; } cfmin = HT_INFINITY; TAILQ_FOREACH(p, &cl->cl_actc, cl_actlist) { if (p->cl_f == 0) { cl->cl_cfmin = 0; return; } if (p->cl_f < cfmin) cfmin = p->cl_f; } cl->cl_cfmin = cfmin; } /* * TAILQ based ellist and actlist implementation * (ion wanted to make a calendar queue based implementation) */ /* * eligible list holds backlogged classes being sorted by their eligible times. * there is one eligible list per interface. */ static void ellist_insert(struct hfsc_class *cl) { struct hfsc_if *hif = cl->cl_hif; struct hfsc_class *p; /* check the last entry first */ if ((p = TAILQ_LAST(&hif->hif_eligible, elighead)) == NULL || p->cl_e <= cl->cl_e) { TAILQ_INSERT_TAIL(&hif->hif_eligible, cl, cl_ellist); return; } TAILQ_FOREACH(p, &hif->hif_eligible, cl_ellist) { if (cl->cl_e < p->cl_e) { TAILQ_INSERT_BEFORE(p, cl, cl_ellist); return; } } ASSERT(0); /* should not reach here */ } static void ellist_remove(struct hfsc_class *cl) { struct hfsc_if *hif = cl->cl_hif; TAILQ_REMOVE(&hif->hif_eligible, cl, cl_ellist); } static void ellist_update(struct hfsc_class *cl) { struct hfsc_if *hif = cl->cl_hif; struct hfsc_class *p, *last; /* * the eligible time of a class increases monotonically. * if the next entry has a larger eligible time, nothing to do. */ p = TAILQ_NEXT(cl, cl_ellist); if (p == NULL || cl->cl_e <= p->cl_e) return; /* check the last entry */ last = TAILQ_LAST(&hif->hif_eligible, elighead); ASSERT(last != NULL); if (last->cl_e <= cl->cl_e) { TAILQ_REMOVE(&hif->hif_eligible, cl, cl_ellist); TAILQ_INSERT_TAIL(&hif->hif_eligible, cl, cl_ellist); return; } /* * the new position must be between the next entry * and the last entry */ while ((p = TAILQ_NEXT(p, cl_ellist)) != NULL) { if (cl->cl_e < p->cl_e) { TAILQ_REMOVE(&hif->hif_eligible, cl, cl_ellist); TAILQ_INSERT_BEFORE(p, cl, cl_ellist); return; } } ASSERT(0); /* should not reach here */ } /* find the class with the minimum deadline among the eligible classes */ struct hfsc_class * hfsc_get_mindl(struct hfsc_if *hif, u_int64_t cur_time) { struct hfsc_class *p, *cl = NULL; TAILQ_FOREACH(p, &hif->hif_eligible, cl_ellist) { if (p->cl_e > cur_time) break; if (cl == NULL || p->cl_d < cl->cl_d) cl = p; } return (cl); } /* * active children list holds backlogged child classes being sorted * by their virtual time. * each intermediate class has one active children list. */ static void actlist_insert(struct hfsc_class *cl) { struct hfsc_class *p; /* check the last entry first */ if ((p = TAILQ_LAST(&cl->cl_parent->cl_actc, acthead)) == NULL || p->cl_vt <= cl->cl_vt) { TAILQ_INSERT_TAIL(&cl->cl_parent->cl_actc, cl, cl_actlist); return; } TAILQ_FOREACH(p, &cl->cl_parent->cl_actc, cl_actlist) { if (cl->cl_vt < p->cl_vt) { TAILQ_INSERT_BEFORE(p, cl, cl_actlist); return; } } ASSERT(0); /* should not reach here */ } static void actlist_remove(struct hfsc_class *cl) { TAILQ_REMOVE(&cl->cl_parent->cl_actc, cl, cl_actlist); } static void actlist_update(struct hfsc_class *cl) { struct hfsc_class *p, *last; /* * the virtual time of a class increases monotonically during its * backlogged period. * if the next entry has a larger virtual time, nothing to do. */ p = TAILQ_NEXT(cl, cl_actlist); if (p == NULL || cl->cl_vt < p->cl_vt) return; /* check the last entry */ last = TAILQ_LAST(&cl->cl_parent->cl_actc, acthead); ASSERT(last != NULL); if (last->cl_vt <= cl->cl_vt) { TAILQ_REMOVE(&cl->cl_parent->cl_actc, cl, cl_actlist); TAILQ_INSERT_TAIL(&cl->cl_parent->cl_actc, cl, cl_actlist); return; } /* * the new position must be between the next entry * and the last entry */ while ((p = TAILQ_NEXT(p, cl_actlist)) != NULL) { if (cl->cl_vt < p->cl_vt) { TAILQ_REMOVE(&cl->cl_parent->cl_actc, cl, cl_actlist); TAILQ_INSERT_BEFORE(p, cl, cl_actlist); return; } } ASSERT(0); /* should not reach here */ } static struct hfsc_class * actlist_firstfit(struct hfsc_class *cl, u_int64_t cur_time) { struct hfsc_class *p; TAILQ_FOREACH(p, &cl->cl_actc, cl_actlist) { if (p->cl_f <= cur_time) return (p); } return (NULL); } /* * service curve support functions * * external service curve parameters * m: bits/sec * d: msec * internal service curve parameters * sm: (bytes/machclk tick) << SM_SHIFT * ism: (machclk ticks/byte) << ISM_SHIFT * dx: machclk ticks * * SM_SHIFT and ISM_SHIFT are scaled in order to keep effective digits. we * should be able to handle 100K-100Gbps linkspeed with 256 MHz machclk * frequency and at least 3 effective digits in decimal. * */ #define SM_SHIFT 24 #define ISM_SHIFT 14 #define SM_MASK ((1LL << SM_SHIFT) - 1) #define ISM_MASK ((1LL << ISM_SHIFT) - 1) static __inline u_int64_t seg_x2y(u_int64_t x, u_int64_t sm) { u_int64_t y; /* * compute * y = x * sm >> SM_SHIFT * but divide it for the upper and lower bits to avoid overflow */ y = (x >> SM_SHIFT) * sm + (((x & SM_MASK) * sm) >> SM_SHIFT); return (y); } static __inline u_int64_t seg_y2x(u_int64_t y, u_int64_t ism) { u_int64_t x; if (y == 0) x = 0; else if (ism == HT_INFINITY) x = HT_INFINITY; else { x = (y >> ISM_SHIFT) * ism + (((y & ISM_MASK) * ism) >> ISM_SHIFT); } return (x); } static __inline u_int64_t m2sm(u_int64_t m) { u_int64_t sm; sm = (m << SM_SHIFT) / 8 / machclk_freq; return (sm); } static __inline u_int64_t m2ism(u_int64_t m) { u_int64_t ism; if (m == 0) ism = HT_INFINITY; else ism = ((u_int64_t)machclk_freq << ISM_SHIFT) * 8 / m; return (ism); } static __inline u_int64_t d2dx(u_int d) { u_int64_t dx; dx = ((u_int64_t)d * machclk_freq) / 1000; return (dx); } static u_int64_t sm2m(u_int64_t sm) { u_int64_t m; m = (sm * 8 * machclk_freq) >> SM_SHIFT; return (m); } static u_int dx2d(u_int64_t dx) { u_int64_t d; d = dx * 1000 / machclk_freq; return ((u_int)d); } static void sc2isc(struct service_curve *sc, struct internal_sc *isc) { isc->sm1 = m2sm(sc->m1); isc->ism1 = m2ism(sc->m1); isc->dx = d2dx(sc->d); isc->dy = seg_x2y(isc->dx, isc->sm1); isc->sm2 = m2sm(sc->m2); isc->ism2 = m2ism(sc->m2); } /* * initialize the runtime service curve with the given internal * service curve starting at (x, y). */ static void rtsc_init(struct runtime_sc *rtsc, struct internal_sc * isc, u_int64_t x, u_int64_t y) { rtsc->x = x; rtsc->y = y; rtsc->sm1 = isc->sm1; rtsc->ism1 = isc->ism1; rtsc->dx = isc->dx; rtsc->dy = isc->dy; rtsc->sm2 = isc->sm2; rtsc->ism2 = isc->ism2; } /* * calculate the y-projection of the runtime service curve by the * given x-projection value */ static u_int64_t rtsc_y2x(struct runtime_sc *rtsc, u_int64_t y) { u_int64_t x; if (y < rtsc->y) x = rtsc->x; else if (y <= rtsc->y + rtsc->dy) { /* x belongs to the 1st segment */ if (rtsc->dy == 0) x = rtsc->x + rtsc->dx; else x = rtsc->x + seg_y2x(y - rtsc->y, rtsc->ism1); } else { /* x belongs to the 2nd segment */ x = rtsc->x + rtsc->dx + seg_y2x(y - rtsc->y - rtsc->dy, rtsc->ism2); } return (x); } static u_int64_t rtsc_x2y(struct runtime_sc *rtsc, u_int64_t x) { u_int64_t y; if (x <= rtsc->x) y = rtsc->y; else if (x <= rtsc->x + rtsc->dx) /* y belongs to the 1st segment */ y = rtsc->y + seg_x2y(x - rtsc->x, rtsc->sm1); else /* y belongs to the 2nd segment */ y = rtsc->y + rtsc->dy + seg_x2y(x - rtsc->x - rtsc->dx, rtsc->sm2); return (y); } /* * update the runtime service curve by taking the minimum of the current * runtime service curve and the service curve starting at (x, y). */ static void rtsc_min(struct runtime_sc *rtsc, struct internal_sc *isc, u_int64_t x, u_int64_t y) { u_int64_t y1, y2, dx, dy; if (isc->sm1 <= isc->sm2) { /* service curve is convex */ y1 = rtsc_x2y(rtsc, x); if (y1 < y) /* the current rtsc is smaller */ return; rtsc->x = x; rtsc->y = y; return; } /* * service curve is concave * compute the two y values of the current rtsc * y1: at x * y2: at (x + dx) */ y1 = rtsc_x2y(rtsc, x); if (y1 <= y) { /* rtsc is below isc, no change to rtsc */ return; } y2 = rtsc_x2y(rtsc, x + isc->dx); if (y2 >= y + isc->dy) { /* rtsc is above isc, replace rtsc by isc */ rtsc->x = x; rtsc->y = y; rtsc->dx = isc->dx; rtsc->dy = isc->dy; return; } /* * the two curves intersect * compute the offsets (dx, dy) using the reverse * function of seg_x2y() * seg_x2y(dx, sm1) == seg_x2y(dx, sm2) + (y1 - y) */ dx = ((y1 - y) << SM_SHIFT) / (isc->sm1 - isc->sm2); /* * check if (x, y1) belongs to the 1st segment of rtsc. * if so, add the offset. */ if (rtsc->x + rtsc->dx > x) dx += rtsc->x + rtsc->dx - x; dy = seg_x2y(dx, isc->sm1); rtsc->x = x; rtsc->y = y; rtsc->dx = dx; rtsc->dy = dy; return; } static void get_class_stats_v0(struct hfsc_classstats_v0 *sp, struct hfsc_class *cl) { sp->class_id = cl->cl_id; sp->class_handle = cl->cl_handle; #define SATU32(x) (u_int32_t)uqmin((x), UINT_MAX) if (cl->cl_rsc != NULL) { sp->rsc.m1 = SATU32(sm2m(cl->cl_rsc->sm1)); sp->rsc.d = dx2d(cl->cl_rsc->dx); sp->rsc.m2 = SATU32(sm2m(cl->cl_rsc->sm2)); } else { sp->rsc.m1 = 0; sp->rsc.d = 0; sp->rsc.m2 = 0; } if (cl->cl_fsc != NULL) { sp->fsc.m1 = SATU32(sm2m(cl->cl_fsc->sm1)); sp->fsc.d = dx2d(cl->cl_fsc->dx); sp->fsc.m2 = SATU32(sm2m(cl->cl_fsc->sm2)); } else { sp->fsc.m1 = 0; sp->fsc.d = 0; sp->fsc.m2 = 0; } if (cl->cl_usc != NULL) { sp->usc.m1 = SATU32(sm2m(cl->cl_usc->sm1)); sp->usc.d = dx2d(cl->cl_usc->dx); sp->usc.m2 = SATU32(sm2m(cl->cl_usc->sm2)); } else { sp->usc.m1 = 0; sp->usc.d = 0; sp->usc.m2 = 0; } #undef SATU32 sp->total = cl->cl_total; sp->cumul = cl->cl_cumul; sp->d = cl->cl_d; sp->e = cl->cl_e; sp->vt = cl->cl_vt; sp->f = cl->cl_f; sp->initvt = cl->cl_initvt; sp->vtperiod = cl->cl_vtperiod; sp->parentperiod = cl->cl_parentperiod; sp->nactive = cl->cl_nactive; sp->vtoff = cl->cl_vtoff; sp->cvtmax = cl->cl_cvtmax; sp->myf = cl->cl_myf; sp->cfmin = cl->cl_cfmin; sp->cvtmin = cl->cl_cvtmin; sp->myfadj = cl->cl_myfadj; sp->vtadj = cl->cl_vtadj; sp->cur_time = read_machclk(); sp->machclk_freq = machclk_freq; sp->qlength = qlen(cl->cl_q); sp->qlimit = qlimit(cl->cl_q); sp->xmit_cnt = cl->cl_stats.xmit_cnt; sp->drop_cnt = cl->cl_stats.drop_cnt; sp->period = cl->cl_stats.period; sp->qtype = qtype(cl->cl_q); #ifdef ALTQ_RED if (q_is_red(cl->cl_q)) red_getstats(cl->cl_red, &sp->red[0]); #endif #ifdef ALTQ_RIO if (q_is_rio(cl->cl_q)) rio_getstats((rio_t *)cl->cl_red, &sp->red[0]); #endif #ifdef ALTQ_CODEL if (q_is_codel(cl->cl_q)) codel_getstats(cl->cl_codel, &sp->codel); #endif } static void get_class_stats_v1(struct hfsc_classstats_v1 *sp, struct hfsc_class *cl) { sp->class_id = cl->cl_id; sp->class_handle = cl->cl_handle; if (cl->cl_rsc != NULL) { sp->rsc.m1 = sm2m(cl->cl_rsc->sm1); sp->rsc.d = dx2d(cl->cl_rsc->dx); sp->rsc.m2 = sm2m(cl->cl_rsc->sm2); } else { sp->rsc.m1 = 0; sp->rsc.d = 0; sp->rsc.m2 = 0; } if (cl->cl_fsc != NULL) { sp->fsc.m1 = sm2m(cl->cl_fsc->sm1); sp->fsc.d = dx2d(cl->cl_fsc->dx); sp->fsc.m2 = sm2m(cl->cl_fsc->sm2); } else { sp->fsc.m1 = 0; sp->fsc.d = 0; sp->fsc.m2 = 0; } if (cl->cl_usc != NULL) { sp->usc.m1 = sm2m(cl->cl_usc->sm1); sp->usc.d = dx2d(cl->cl_usc->dx); sp->usc.m2 = sm2m(cl->cl_usc->sm2); } else { sp->usc.m1 = 0; sp->usc.d = 0; sp->usc.m2 = 0; } sp->total = cl->cl_total; sp->cumul = cl->cl_cumul; sp->d = cl->cl_d; sp->e = cl->cl_e; sp->vt = cl->cl_vt; sp->f = cl->cl_f; sp->initvt = cl->cl_initvt; sp->vtperiod = cl->cl_vtperiod; sp->parentperiod = cl->cl_parentperiod; sp->nactive = cl->cl_nactive; sp->vtoff = cl->cl_vtoff; sp->cvtmax = cl->cl_cvtmax; sp->myf = cl->cl_myf; sp->cfmin = cl->cl_cfmin; sp->cvtmin = cl->cl_cvtmin; sp->myfadj = cl->cl_myfadj; sp->vtadj = cl->cl_vtadj; sp->cur_time = read_machclk(); sp->machclk_freq = machclk_freq; sp->qlength = qlen(cl->cl_q); sp->qlimit = qlimit(cl->cl_q); sp->xmit_cnt = cl->cl_stats.xmit_cnt; sp->drop_cnt = cl->cl_stats.drop_cnt; sp->period = cl->cl_stats.period; sp->qtype = qtype(cl->cl_q); #ifdef ALTQ_RED if (q_is_red(cl->cl_q)) red_getstats(cl->cl_red, &sp->red[0]); #endif #ifdef ALTQ_RIO if (q_is_rio(cl->cl_q)) rio_getstats((rio_t *)cl->cl_red, &sp->red[0]); #endif #ifdef ALTQ_CODEL if (q_is_codel(cl->cl_q)) codel_getstats(cl->cl_codel, &sp->codel); #endif } /* convert a class handle to the corresponding class pointer */ static struct hfsc_class * clh_to_clp(struct hfsc_if *hif, u_int32_t chandle) { int i; struct hfsc_class *cl; if (chandle == 0) return (NULL); /* * first, try optimistically the slot matching the lower bits of * the handle. if it fails, do the linear table search. */ i = chandle % HFSC_MAX_CLASSES; if ((cl = hif->hif_class_tbl[i]) != NULL && cl->cl_handle == chandle) return (cl); for (i = 0; i < HFSC_MAX_CLASSES; i++) if ((cl = hif->hif_class_tbl[i]) != NULL && cl->cl_handle == chandle) return (cl); return (NULL); } #endif /* ALTQ_HFSC */