git: 56dc95b249dc - stable/12 - Revert "if_epair: rework"
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Date: Thu, 24 Mar 2022 13:14:36 UTC
The branch stable/12 has been updated by kp: URL: https://cgit.FreeBSD.org/src/commit/?id=56dc95b249dceb30367a77dccd0231cbb08dc1f7 commit 56dc95b249dceb30367a77dccd0231cbb08dc1f7 Author: Kristof Provost <kp@FreeBSD.org> AuthorDate: 2022-03-21 14:41:32 +0000 Commit: Kristof Provost <kp@FreeBSD.org> CommitDate: 2022-03-24 09:44:40 +0000 Revert "if_epair: rework" Revert the recent performance rework of if_epair. It relies on functions like atomic_testandclear_long() which are not available on all platforms in stable/12. This reverts commits b1a3f8dccb6203036b7ee81201fd5b5a8de36f0d, fb3644ab2afe777fdd2539bc996a390443f052f1, ca7af63e88f8cc96865d45e020a57b3062631388, 092da35a0d80af7a3e5c5c22cbeddb6cffbd9524, and 7c2b681b33fc78ed06c7e9e65eeebb2ab5420586. This is a direct commit to stable/12. --- sys/modules/if_epair/Makefile | 2 +- sys/net/if_epair.c | 832 ++++++++++++++++++++++++++---------------- 2 files changed, 509 insertions(+), 325 deletions(-) diff --git a/sys/modules/if_epair/Makefile b/sys/modules/if_epair/Makefile index 8b063623f2e8..3e102413bfe2 100644 --- a/sys/modules/if_epair/Makefile +++ b/sys/modules/if_epair/Makefile @@ -3,6 +3,6 @@ .PATH: ${SRCTOP}/sys/net KMOD= if_epair -SRCS= bus_if.h device_if.h if_epair.c opt_rss.h opt_inet.h opt_inet6.h +SRCS= bus_if.h device_if.h if_epair.c .include <bsd.kmod.mk> diff --git a/sys/net/if_epair.c b/sys/net/if_epair.c index 4b01e97c354d..cd11036ad028 100644 --- a/sys/net/if_epair.c +++ b/sys/net/if_epair.c @@ -2,8 +2,8 @@ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD * * Copyright (c) 2008 The FreeBSD Foundation + * Copyright (c) 2009-2010 Bjoern A. Zeeb <bz@FreeBSD.org> * All rights reserved. - * Copyright (c) 2009-2021 Bjoern A. Zeeb <bz@FreeBSD.org> * * This software was developed by CK Software GmbH under sponsorship * from the FreeBSD Foundation. @@ -37,14 +37,21 @@ * This is mostly intended to be used to provide connectivity between * different virtual network stack instances. */ +/* + * Things to re-think once we have more experience: + * - ifp->if_reassign function once we can test with vimage. Depending on + * how if_vmove() is going to be improved. + * - Real random etheraddrs that are checked to be uniquish; we would need + * to re-do them in case we move the interface between network stacks + * in a private if_reassign function. + * In case we bridge to a real interface/network or between indepedent + * epairs on multiple stacks/machines, we may need this. + * For now let the user handle that case. + */ #include <sys/cdefs.h> __FBSDID("$FreeBSD$"); -#include "opt_rss.h" -#include "opt_inet.h" -#include "opt_inet6.h" - #include <sys/param.h> #include <sys/hash.h> #include <sys/jail.h> @@ -54,16 +61,13 @@ __FBSDID("$FreeBSD$"); #include <sys/mbuf.h> #include <sys/module.h> #include <sys/proc.h> +#include <sys/refcount.h> #include <sys/queue.h> -#include <sys/sched.h> #include <sys/smp.h> #include <sys/socket.h> #include <sys/sockio.h> -#include <sys/taskqueue.h> +#include <sys/sysctl.h> #include <sys/types.h> -#include <sys/buf_ring.h> -#include <sys/bus.h> -#include <sys/interrupt.h> #include <net/bpf.h> #include <net/ethernet.h> @@ -74,66 +78,121 @@ __FBSDID("$FreeBSD$"); #include <net/if_var.h> #include <net/if_types.h> #include <net/netisr.h> -#ifdef RSS -#include <net/rss_config.h> -#ifdef INET -#include <netinet/in_rss.h> -#endif -#ifdef INET6 -#include <netinet6/in6_rss.h> -#endif -#endif #include <net/vnet.h> +SYSCTL_DECL(_net_link); +static SYSCTL_NODE(_net_link, OID_AUTO, epair, CTLFLAG_RW, 0, "epair sysctl"); + +#ifdef EPAIR_DEBUG +static int epair_debug = 0; +SYSCTL_INT(_net_link_epair, OID_AUTO, epair_debug, CTLFLAG_RW, + &epair_debug, 0, "if_epair(4) debugging."); +#define DPRINTF(fmt, arg...) \ + if (epair_debug) \ + printf("[%s:%d] " fmt, __func__, __LINE__, ##arg) +#else +#define DPRINTF(fmt, arg...) +#endif + +static void epair_nh_sintr(struct mbuf *); +static struct mbuf *epair_nh_m2cpuid(struct mbuf *, uintptr_t, u_int *); +static void epair_nh_drainedcpu(u_int); + +static void epair_start_locked(struct ifnet *); +static int epair_media_change(struct ifnet *); +static void epair_media_status(struct ifnet *, struct ifmediareq *); + static int epair_clone_match(struct if_clone *, const char *); static int epair_clone_create(struct if_clone *, char *, size_t, caddr_t); static int epair_clone_destroy(struct if_clone *, struct ifnet *); static const char epairname[] = "epair"; -#define RXRSIZE 4096 /* Probably overkill by 4-8x. */ +static unsigned int next_index = 0; -static MALLOC_DEFINE(M_EPAIR, epairname, - "Pair of virtual cross-over connected Ethernet-like interfaces"); +/* Netisr related definitions and sysctl. */ +static struct netisr_handler epair_nh = { + .nh_name = epairname, + .nh_proto = NETISR_EPAIR, + .nh_policy = NETISR_POLICY_CPU, + .nh_handler = epair_nh_sintr, + .nh_m2cpuid = epair_nh_m2cpuid, + .nh_drainedcpu = epair_nh_drainedcpu, +}; -VNET_DEFINE_STATIC(struct if_clone *, epair_cloner); -#define V_epair_cloner VNET(epair_cloner) +static int +sysctl_epair_netisr_maxqlen(SYSCTL_HANDLER_ARGS) +{ + int error, qlimit; -static unsigned int next_index = 0; -#define EPAIR_LOCK_INIT() mtx_init(&epair_n_index_mtx, "epairidx", \ - NULL, MTX_DEF) -#define EPAIR_LOCK_DESTROY() mtx_destroy(&epair_n_index_mtx) -#define EPAIR_LOCK() mtx_lock(&epair_n_index_mtx) -#define EPAIR_UNLOCK() mtx_unlock(&epair_n_index_mtx) - -#define BIT_QUEUE_TASK 0 -#define BIT_MBUF_QUEUED 1 - -struct epair_softc; -struct epair_queue { - int id; - struct buf_ring *rxring[2]; - volatile int ridx; /* 0 || 1 */ - volatile long state; /* taskqueue coordination */ - struct task tx_task; - struct epair_softc *sc; -}; + netisr_getqlimit(&epair_nh, &qlimit); + error = sysctl_handle_int(oidp, &qlimit, 0, req); + if (error || !req->newptr) + return (error); + if (qlimit < 1) + return (EINVAL); + return (netisr_setqlimit(&epair_nh, qlimit)); +} +SYSCTL_PROC(_net_link_epair, OID_AUTO, netisr_maxqlen, CTLTYPE_INT|CTLFLAG_RW, + 0, 0, sysctl_epair_netisr_maxqlen, "I", + "Maximum if_epair(4) netisr \"hw\" queue length"); -static struct mtx epair_n_index_mtx; struct epair_softc { - struct ifnet *ifp; /* This ifp. */ - struct ifnet *oifp; /* other ifp of pair. */ - int num_queues; - struct epair_queue *queues; - struct ifmedia media; /* Media config (fake). */ - STAILQ_ENTRY(epair_softc) entry; + struct ifnet *ifp; /* This ifp. */ + struct ifnet *oifp; /* other ifp of pair. */ + struct ifmedia media; /* Media config (fake). */ + u_int refcount; /* # of mbufs in flight. */ + u_int cpuid; /* CPU ID assigned upon creation. */ + void (*if_qflush)(struct ifnet *); + /* Original if_qflush routine. */ }; -struct epair_tasks_t { - int tasks; - struct taskqueue *tq[MAXCPU]; +/* + * Per-CPU list of ifps with data in the ifq that needs to be flushed + * to the netisr ``hw'' queue before we allow any further direct queuing + * to the ``hw'' queue. + */ +struct epair_ifp_drain { + STAILQ_ENTRY(epair_ifp_drain) ifp_next; + struct ifnet *ifp; }; +STAILQ_HEAD(eid_list, epair_ifp_drain); + +#define EPAIR_LOCK_INIT(dpcpu) mtx_init(&(dpcpu)->if_epair_mtx, \ + "if_epair", NULL, MTX_DEF) +#define EPAIR_LOCK_DESTROY(dpcpu) mtx_destroy(&(dpcpu)->if_epair_mtx) +#define EPAIR_LOCK_ASSERT(dpcpu) mtx_assert(&(dpcpu)->if_epair_mtx, \ + MA_OWNED) +#define EPAIR_LOCK(dpcpu) mtx_lock(&(dpcpu)->if_epair_mtx) +#define EPAIR_UNLOCK(dpcpu) mtx_unlock(&(dpcpu)->if_epair_mtx) + +#ifdef INVARIANTS +#define EPAIR_REFCOUNT_INIT(r, v) refcount_init((r), (v)) +#define EPAIR_REFCOUNT_AQUIRE(r) refcount_acquire((r)) +#define EPAIR_REFCOUNT_RELEASE(r) refcount_release((r)) +#define EPAIR_REFCOUNT_ASSERT(a, p) KASSERT(a, p) +#else +#define EPAIR_REFCOUNT_INIT(r, v) +#define EPAIR_REFCOUNT_AQUIRE(r) +#define EPAIR_REFCOUNT_RELEASE(r) +#define EPAIR_REFCOUNT_ASSERT(a, p) +#endif -static struct epair_tasks_t epair_tasks; +static MALLOC_DEFINE(M_EPAIR, epairname, + "Pair of virtual cross-over connected Ethernet-like interfaces"); + +VNET_DEFINE_STATIC(struct if_clone *, epair_cloner); +#define V_epair_cloner VNET(epair_cloner) + +/* + * DPCPU area and functions. + */ +struct epair_dpcpu { + struct mtx if_epair_mtx; /* Per-CPU locking. */ + int epair_drv_flags; /* Per-CPU ``hw'' drv flags. */ + struct eid_list epair_ifp_drain_list; /* Per-CPU list of ifps with + * data in the ifq. */ +}; +DPCPU_DEFINE(struct epair_dpcpu, epair_dpcpu); static void epair_clear_mbuf(struct mbuf *m) @@ -142,199 +201,313 @@ epair_clear_mbuf(struct mbuf *m) } static void -epair_if_input(struct epair_softc *sc, struct epair_queue *q, int ridx) +epair_dpcpu_init(void) { - struct epoch_tracker et; - struct ifnet *ifp; - struct mbuf *m; + struct epair_dpcpu *epair_dpcpu; + struct eid_list *s; + u_int cpuid; + + CPU_FOREACH(cpuid) { + epair_dpcpu = DPCPU_ID_PTR(cpuid, epair_dpcpu); + + /* Initialize per-cpu lock. */ + EPAIR_LOCK_INIT(epair_dpcpu); + + /* Driver flags are per-cpu as are our netisr "hw" queues. */ + epair_dpcpu->epair_drv_flags = 0; + + /* + * Initialize per-cpu drain list. + * Manually do what STAILQ_HEAD_INITIALIZER would do. + */ + s = &epair_dpcpu->epair_ifp_drain_list; + s->stqh_first = NULL; + s->stqh_last = &s->stqh_first; + } +} - ifp = sc->ifp; - NET_EPOCH_ENTER_ET(et); - CURVNET_SET(ifp->if_vnet); - while (! buf_ring_empty(q->rxring[ridx])) { - m = buf_ring_dequeue_mc(q->rxring[ridx]); - if (m == NULL) - continue; +static void +epair_dpcpu_detach(void) +{ + struct epair_dpcpu *epair_dpcpu; + u_int cpuid; - MPASS((m->m_pkthdr.csum_flags & CSUM_SND_TAG) == 0); - (*ifp->if_input)(ifp, m); + CPU_FOREACH(cpuid) { + epair_dpcpu = DPCPU_ID_PTR(cpuid, epair_dpcpu); + + /* Destroy per-cpu lock. */ + EPAIR_LOCK_DESTROY(epair_dpcpu); } - CURVNET_RESTORE(); - NET_EPOCH_EXIT_ET(et); } -static void -epair_tx_start_deferred(void *arg, int pending) +/* + * Helper functions. + */ +static u_int +cpuid_from_ifp(struct ifnet *ifp) { - struct epair_queue *q = (struct epair_queue *)arg; - struct epair_softc *sc = q->sc; - int ridx, nidx; - - if_ref(sc->ifp); - ridx = atomic_load_int(&q->ridx); - do { - nidx = (ridx == 0) ? 1 : 0; - } while (!atomic_fcmpset_int(&q->ridx, &ridx, nidx)); - epair_if_input(sc, q, ridx); - - atomic_clear_long(&q->state, (1 << BIT_QUEUE_TASK)); - if (atomic_testandclear_long(&q->state, BIT_MBUF_QUEUED)) - taskqueue_enqueue(epair_tasks.tq[q->id], &q->tx_task); - - if_rele(sc->ifp); + struct epair_softc *sc; + + if (ifp == NULL) + return (0); + sc = ifp->if_softc; + + return (sc->cpuid); } -static int -epair_menq(struct mbuf *m, struct epair_softc *osc) +/* + * Netisr handler functions. + */ +static void +epair_nh_sintr(struct mbuf *m) { - struct ifnet *ifp, *oifp; - int len, ret; - int ridx; - short mflags; - struct epair_queue *q = NULL; - uint32_t bucket; -#ifdef RSS - struct ether_header *eh; -#endif + struct ifnet *ifp; + struct epair_softc *sc __unused; - /* - * I know this looks weird. We pass the "other sc" as we need that one - * and can get both ifps from it as well. - */ - oifp = osc->ifp; - ifp = osc->oifp; + ifp = m->m_pkthdr.rcvif; + (*ifp->if_input)(ifp, m); + sc = ifp->if_softc; + EPAIR_REFCOUNT_RELEASE(&sc->refcount); + EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1, + ("%s: ifp=%p sc->refcount not >= 1: %d", + __func__, ifp, sc->refcount)); + DPRINTF("ifp=%p refcount=%u\n", ifp, sc->refcount); +} - M_ASSERTPKTHDR(m); - epair_clear_mbuf(m); - if_setrcvif(m, oifp); - M_SETFIB(m, oifp->if_fib); +static struct mbuf * +epair_nh_m2cpuid(struct mbuf *m, uintptr_t source, u_int *cpuid) +{ - /* Save values as once the mbuf is queued, it's not ours anymore. */ - len = m->m_pkthdr.len; - mflags = m->m_flags; + *cpuid = cpuid_from_ifp(m->m_pkthdr.rcvif); - MPASS(m->m_nextpkt == NULL); - MPASS((m->m_pkthdr.csum_flags & CSUM_SND_TAG) == 0); + return (m); +} -#ifdef RSS - ret = rss_m2bucket(m, &bucket); - if (ret) { - /* Actually hash the packet. */ - eh = mtod(m, struct ether_header *); +static void +epair_nh_drainedcpu(u_int cpuid) +{ + struct epair_dpcpu *epair_dpcpu; + struct epair_ifp_drain *elm, *tvar; + struct ifnet *ifp; - switch (ntohs(eh->ether_type)) { -#ifdef INET - case ETHERTYPE_IP: - rss_soft_m2cpuid_v4(m, 0, &bucket); - break; -#endif -#ifdef INET6 - case ETHERTYPE_IPV6: - rss_soft_m2cpuid_v6(m, 0, &bucket); - break; -#endif - default: - bucket = 0; + epair_dpcpu = DPCPU_ID_PTR(cpuid, epair_dpcpu); + EPAIR_LOCK(epair_dpcpu); + /* + * Assume our "hw" queue and possibly ifq will be emptied + * again. In case we will overflow the "hw" queue while + * draining, epair_start_locked will set IFF_DRV_OACTIVE + * again and we will stop and return. + */ + STAILQ_FOREACH_SAFE(elm, &epair_dpcpu->epair_ifp_drain_list, + ifp_next, tvar) { + ifp = elm->ifp; + epair_dpcpu->epair_drv_flags &= ~IFF_DRV_OACTIVE; + ifp->if_drv_flags &= ~IFF_DRV_OACTIVE; + epair_start_locked(ifp); + + IFQ_LOCK(&ifp->if_snd); + if (IFQ_IS_EMPTY(&ifp->if_snd)) { + struct epair_softc *sc __unused; + + STAILQ_REMOVE(&epair_dpcpu->epair_ifp_drain_list, + elm, epair_ifp_drain, ifp_next); + /* The cached ifp goes off the list. */ + sc = ifp->if_softc; + EPAIR_REFCOUNT_RELEASE(&sc->refcount); + EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1, + ("%s: ifp=%p sc->refcount not >= 1: %d", + __func__, ifp, sc->refcount)); + free(elm, M_EPAIR); + } + IFQ_UNLOCK(&ifp->if_snd); + + if ((ifp->if_drv_flags & IFF_DRV_OACTIVE) != 0) { + /* Our "hw"q overflew again. */ + epair_dpcpu->epair_drv_flags |= IFF_DRV_OACTIVE; + DPRINTF("hw queue length overflow at %u\n", + epair_nh.nh_qlimit); break; } } - bucket %= osc->num_queues; -#else - bucket = 0; -#endif - q = &osc->queues[bucket]; - - atomic_set_long(&q->state, (1 << BIT_MBUF_QUEUED)); - ridx = atomic_load_int(&q->ridx); - ret = buf_ring_enqueue(q->rxring[ridx], m); - if (ret != 0) { - /* Ring is full. */ - if_inc_counter(ifp, IFCOUNTER_OQDROPS, 1); - m_freem(m); - return (0); + EPAIR_UNLOCK(epair_dpcpu); +} + +/* + * Network interface (`if') related functions. + */ +static void +epair_remove_ifp_from_draining(struct ifnet *ifp) +{ + struct epair_dpcpu *epair_dpcpu; + struct epair_ifp_drain *elm, *tvar; + u_int cpuid; + + CPU_FOREACH(cpuid) { + epair_dpcpu = DPCPU_ID_PTR(cpuid, epair_dpcpu); + EPAIR_LOCK(epair_dpcpu); + STAILQ_FOREACH_SAFE(elm, &epair_dpcpu->epair_ifp_drain_list, + ifp_next, tvar) { + if (ifp == elm->ifp) { + struct epair_softc *sc __unused; + + STAILQ_REMOVE( + &epair_dpcpu->epair_ifp_drain_list, elm, + epair_ifp_drain, ifp_next); + /* The cached ifp goes off the list. */ + sc = ifp->if_softc; + EPAIR_REFCOUNT_RELEASE(&sc->refcount); + EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1, + ("%s: ifp=%p sc->refcount not >= 1: %d", + __func__, ifp, sc->refcount)); + free(elm, M_EPAIR); + } + } + EPAIR_UNLOCK(epair_dpcpu); } +} - if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); - /* - * IFQ_HANDOFF_ADJ/ip_handoff() update statistics, - * but as we bypass all this we have to duplicate - * the logic another time. - */ - if_inc_counter(ifp, IFCOUNTER_OBYTES, len); - if (mflags & (M_BCAST|M_MCAST)) - if_inc_counter(ifp, IFCOUNTER_OMCASTS, 1); - /* Someone else received the packet. */ - if_inc_counter(oifp, IFCOUNTER_IPACKETS, 1); +static int +epair_add_ifp_for_draining(struct ifnet *ifp) +{ + struct epair_dpcpu *epair_dpcpu; + struct epair_softc *sc; + struct epair_ifp_drain *elm = NULL; - if (!atomic_testandset_long(&q->state, BIT_QUEUE_TASK)) - taskqueue_enqueue(epair_tasks.tq[bucket], &q->tx_task); + sc = ifp->if_softc; + epair_dpcpu = DPCPU_ID_PTR(sc->cpuid, epair_dpcpu); + EPAIR_LOCK_ASSERT(epair_dpcpu); + STAILQ_FOREACH(elm, &epair_dpcpu->epair_ifp_drain_list, ifp_next) + if (elm->ifp == ifp) + break; + /* If the ifp is there already, return success. */ + if (elm != NULL) + return (0); + + elm = malloc(sizeof(struct epair_ifp_drain), M_EPAIR, M_NOWAIT|M_ZERO); + if (elm == NULL) + return (ENOMEM); + + elm->ifp = ifp; + /* Add a reference for the ifp pointer on the list. */ + EPAIR_REFCOUNT_AQUIRE(&sc->refcount); + STAILQ_INSERT_TAIL(&epair_dpcpu->epair_ifp_drain_list, elm, ifp_next); return (0); } static void -epair_start(struct ifnet *ifp) +epair_start_locked(struct ifnet *ifp) { + struct epair_dpcpu *epair_dpcpu; struct mbuf *m; struct epair_softc *sc; struct ifnet *oifp; + int error; + + DPRINTF("ifp=%p\n", ifp); + sc = ifp->if_softc; + epair_dpcpu = DPCPU_ID_PTR(sc->cpuid, epair_dpcpu); + EPAIR_LOCK_ASSERT(epair_dpcpu); + + if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) + return; + if ((ifp->if_flags & IFF_UP) == 0) + return; /* * We get packets here from ether_output via if_handoff() * and need to put them into the input queue of the oifp - * and will put the packet into the receive-queue (rxq) of the - * other interface (oifp) of our pair. + * and call oifp->if_input() via netisr/epair_sintr(). */ - sc = ifp->if_softc; oifp = sc->oifp; sc = oifp->if_softc; for (;;) { IFQ_DEQUEUE(&ifp->if_snd, m); if (m == NULL) break; - M_ASSERTPKTHDR(m); BPF_MTAP(ifp, m); - /* In case either interface is not usable drop the packet. */ - if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 || - (ifp->if_flags & IFF_UP) == 0 || - (oifp->if_drv_flags & IFF_DRV_RUNNING) == 0 || - (oifp->if_flags & IFF_UP) == 0) { + /* + * In case the outgoing interface is not usable, + * drop the packet. + */ + if ((oifp->if_drv_flags & IFF_DRV_RUNNING) == 0 || + (oifp->if_flags & IFF_UP) ==0) { + if_inc_counter(ifp, IFCOUNTER_OERRORS, 1); m_freem(m); continue; } - - (void) epair_menq(m, sc); + DPRINTF("packet %s -> %s\n", ifp->if_xname, oifp->if_xname); + + epair_clear_mbuf(m); + + /* + * Add a reference so the interface cannot go while the + * packet is in transit as we rely on rcvif to stay valid. + */ + EPAIR_REFCOUNT_AQUIRE(&sc->refcount); + m->m_pkthdr.rcvif = oifp; + CURVNET_SET_QUIET(oifp->if_vnet); + error = netisr_queue(NETISR_EPAIR, m); + CURVNET_RESTORE(); + if (!error) { + if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); + /* Someone else received the packet. */ + if_inc_counter(oifp, IFCOUNTER_IPACKETS, 1); + } else { + /* The packet was freed already. */ + epair_dpcpu->epair_drv_flags |= IFF_DRV_OACTIVE; + ifp->if_drv_flags |= IFF_DRV_OACTIVE; + (void) epair_add_ifp_for_draining(ifp); + if_inc_counter(ifp, IFCOUNTER_OERRORS, 1); + EPAIR_REFCOUNT_RELEASE(&sc->refcount); + EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1, + ("%s: ifp=%p sc->refcount not >= 1: %d", + __func__, oifp, sc->refcount)); + } } } +static void +epair_start(struct ifnet *ifp) +{ + struct epair_dpcpu *epair_dpcpu; + + epair_dpcpu = DPCPU_ID_PTR(cpuid_from_ifp(ifp), epair_dpcpu); + EPAIR_LOCK(epair_dpcpu); + epair_start_locked(ifp); + EPAIR_UNLOCK(epair_dpcpu); +} + static int -epair_transmit(struct ifnet *ifp, struct mbuf *m) +epair_transmit_locked(struct ifnet *ifp, struct mbuf *m) { + struct epair_dpcpu *epair_dpcpu; struct epair_softc *sc; struct ifnet *oifp; int error, len; short mflags; + DPRINTF("ifp=%p m=%p\n", ifp, m); + sc = ifp->if_softc; + epair_dpcpu = DPCPU_ID_PTR(sc->cpuid, epair_dpcpu); + EPAIR_LOCK_ASSERT(epair_dpcpu); + if (m == NULL) return (0); - - M_ASSERTPKTHDR(m); - + /* * We are not going to use the interface en/dequeue mechanism * on the TX side. We are called from ether_output_frame() - * and will put the packet into the receive-queue (rxq) of the - * other interface (oifp) of our pair. + * and will put the packet into the incoming queue of the + * other interface of our pair via the netsir. */ if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { m_freem(m); - if_inc_counter(ifp, IFCOUNTER_OERRORS, 1); return (ENXIO); } if ((ifp->if_flags & IFF_UP) == 0) { m_freem(m); - if_inc_counter(ifp, IFCOUNTER_OERRORS, 1); return (ENETDOWN); } @@ -344,16 +517,16 @@ epair_transmit(struct ifnet *ifp, struct mbuf *m) * In case the outgoing interface is not usable, * drop the packet. */ - sc = ifp->if_softc; oifp = sc->oifp; if ((oifp->if_drv_flags & IFF_DRV_RUNNING) == 0 || - (oifp->if_flags & IFF_UP) == 0) { + (oifp->if_flags & IFF_UP) ==0) { if_inc_counter(ifp, IFCOUNTER_OERRORS, 1); m_freem(m); return (0); } len = m->m_pkthdr.len; mflags = m->m_flags; + DPRINTF("packet %s -> %s\n", ifp->if_xname, oifp->if_xname); #ifdef ALTQ /* Support ALTQ via the classic if_start() path. */ @@ -367,17 +540,99 @@ epair_transmit(struct ifnet *ifp, struct mbuf *m) if_inc_counter(ifp, IFCOUNTER_OBYTES, len); if (mflags & (M_BCAST|M_MCAST)) if_inc_counter(ifp, IFCOUNTER_OMCASTS, 1); - epair_start(ifp); + + if ((ifp->if_drv_flags & IFF_DRV_OACTIVE) == 0) + epair_start_locked(ifp); + else + (void)epair_add_ifp_for_draining(ifp); } return (error); } IF_UNLOCK(&ifp->if_snd); #endif - error = epair_menq(m, oifp->if_softc); + if ((epair_dpcpu->epair_drv_flags & IFF_DRV_OACTIVE) != 0) { + /* + * Our hardware queue is full, try to fall back + * queuing to the ifq but do not call ifp->if_start. + * Either we are lucky or the packet is gone. + */ + IFQ_ENQUEUE(&ifp->if_snd, m, error); + if (!error) + (void)epair_add_ifp_for_draining(ifp); + return (error); + } + + epair_clear_mbuf(m); + + sc = oifp->if_softc; + /* + * Add a reference so the interface cannot go while the + * packet is in transit as we rely on rcvif to stay valid. + */ + EPAIR_REFCOUNT_AQUIRE(&sc->refcount); + m->m_pkthdr.rcvif = oifp; + CURVNET_SET_QUIET(oifp->if_vnet); + error = netisr_queue(NETISR_EPAIR, m); + CURVNET_RESTORE(); + if (!error) { + if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); + /* + * IFQ_HANDOFF_ADJ/ip_handoff() update statistics, + * but as we bypass all this we have to duplicate + * the logic another time. + */ + if_inc_counter(ifp, IFCOUNTER_OBYTES, len); + if (mflags & (M_BCAST|M_MCAST)) + if_inc_counter(ifp, IFCOUNTER_OMCASTS, 1); + /* Someone else received the packet. */ + if_inc_counter(oifp, IFCOUNTER_IPACKETS, 1); + } else { + /* The packet was freed already. */ + epair_dpcpu->epair_drv_flags |= IFF_DRV_OACTIVE; + ifp->if_drv_flags |= IFF_DRV_OACTIVE; + if_inc_counter(ifp, IFCOUNTER_OERRORS, 1); + EPAIR_REFCOUNT_RELEASE(&sc->refcount); + EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1, + ("%s: ifp=%p sc->refcount not >= 1: %d", + __func__, oifp, sc->refcount)); + } + return (error); } +static int +epair_transmit(struct ifnet *ifp, struct mbuf *m) +{ + struct epair_dpcpu *epair_dpcpu; + int error; + + epair_dpcpu = DPCPU_ID_PTR(cpuid_from_ifp(ifp), epair_dpcpu); + EPAIR_LOCK(epair_dpcpu); + error = epair_transmit_locked(ifp, m); + EPAIR_UNLOCK(epair_dpcpu); + return (error); +} + +static void +epair_qflush(struct ifnet *ifp) +{ + struct epair_softc *sc; + + sc = ifp->if_softc; + KASSERT(sc != NULL, ("%s: ifp=%p, epair_softc gone? sc=%p\n", + __func__, ifp, sc)); + /* + * Remove this ifp from all backpointer lists. The interface will not + * usable for flushing anyway nor should it have anything to flush + * after if_qflush(). + */ + epair_remove_ifp_from_draining(ifp); + + if (sc->if_qflush) + sc->if_qflush(ifp); +} + static int epair_media_change(struct ifnet *ifp __unused) { @@ -446,6 +701,8 @@ epair_clone_match(struct if_clone *ifc, const char *name) { const char *cp; + DPRINTF("name='%s'\n", name); + /* * Our base name is epair. * Our interfaces will be named epair<n>[ab]. @@ -534,29 +791,17 @@ epair_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params) /* Allocate memory for both [ab] interfaces */ sca = malloc(sizeof(struct epair_softc), M_EPAIR, M_WAITOK | M_ZERO); + EPAIR_REFCOUNT_INIT(&sca->refcount, 1); sca->ifp = if_alloc(IFT_ETHER); - sca->num_queues = epair_tasks.tasks; if (sca->ifp == NULL) { free(sca, M_EPAIR); ifc_free_unit(ifc, unit); return (ENOSPC); } - sca->queues = mallocarray(sca->num_queues, sizeof(struct epair_queue), - M_EPAIR, M_WAITOK); - for (int i = 0; i < sca->num_queues; i++) { - struct epair_queue *q = &sca->queues[i]; - q->id = i; - q->rxring[0] = buf_ring_alloc(RXRSIZE, M_EPAIR, M_WAITOK, NULL); - q->rxring[1] = buf_ring_alloc(RXRSIZE, M_EPAIR, M_WAITOK, NULL); - q->ridx = 0; - q->state = 0; - q->sc = sca; - TASK_INIT(&q->tx_task, 0, epair_tx_start_deferred, q); - } scb = malloc(sizeof(struct epair_softc), M_EPAIR, M_WAITOK | M_ZERO); + EPAIR_REFCOUNT_INIT(&scb->refcount, 1); scb->ifp = if_alloc(IFT_ETHER); - scb->num_queues = epair_tasks.tasks; if (scb->ifp == NULL) { free(scb, M_EPAIR); if_free(sca->ifp); @@ -564,33 +809,23 @@ epair_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params) ifc_free_unit(ifc, unit); return (ENOSPC); } - scb->queues = mallocarray(scb->num_queues, sizeof(struct epair_queue), - M_EPAIR, M_WAITOK); - for (int i = 0; i < scb->num_queues; i++) { - struct epair_queue *q = &scb->queues[i]; - q->id = i; - q->rxring[0] = buf_ring_alloc(RXRSIZE, M_EPAIR, M_WAITOK, NULL); - q->rxring[1] = buf_ring_alloc(RXRSIZE, M_EPAIR, M_WAITOK, NULL); - q->ridx = 0; - q->state = 0; - q->sc = scb; - TASK_INIT(&q->tx_task, 0, epair_tx_start_deferred, q); - } - + /* * Cross-reference the interfaces so we will be able to free both. */ sca->oifp = scb->ifp; scb->oifp = sca->ifp; - EPAIR_LOCK(); -#ifdef SMP - /* Get an approximate distribution. */ - hash = next_index % mp_ncpus; -#else - hash = 0; -#endif - EPAIR_UNLOCK(); + /* + * Calculate the cpuid for netisr queueing based on the + * ifIndex of the interfaces. As long as we cannot configure + * this or use cpuset information easily we cannot guarantee + * cache locality but we can at least allow parallelism. + */ + sca->cpuid = + netisr_get_cpuid(sca->ifp->if_index); + scb->cpuid = + netisr_get_cpuid(scb->ifp->if_index); /* Initialise pseudo media types. */ ifmedia_init(&sca->media, 0, epair_media_change, epair_media_status); @@ -627,14 +862,12 @@ epair_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params) if (hostid == 0) arc4rand(&hostid, sizeof(hostid), 0); - EPAIR_LOCK(); if (ifp->if_index > next_index) next_index = ifp->if_index; else next_index++; key[0] = (uint32_t)next_index; - EPAIR_UNLOCK(); key[1] = (uint32_t)(hostid & 0xffffffff); key[2] = (uint32_t)((hostid >> 32) & 0xfffffffff); hash = jenkins_hash32(key, 3, 0); @@ -643,8 +876,10 @@ epair_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params) memcpy(&eaddr[1], &hash, 4); eaddr[5] = 0x0a; ether_ifattach(ifp, eaddr); - ifp->if_baudrate = IF_Gbps(10); /* arbitrary maximum */ + sca->if_qflush = ifp->if_qflush; + ifp->if_qflush = epair_qflush; ifp->if_transmit = epair_transmit; + ifp->if_baudrate = IF_Gbps(10); /* arbitrary maximum */ /* Swap the name and finish initialization of interface <n>b. */ *dp = 'b'; @@ -669,43 +904,27 @@ epair_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params) strlcpy(name, scb->ifp->if_xname, len); epair_clone_add(ifc, scb); - ifp->if_baudrate = IF_Gbps(10); /* arbitrary maximum */ + scb->if_qflush = ifp->if_qflush; + ifp->if_qflush = epair_qflush; ifp->if_transmit = epair_transmit; + ifp->if_baudrate = IF_Gbps(10); /* arbitrary maximum */ /* * Restore name to <n>a as the ifp for this will go into the * cloner list for the initial call. */ strlcpy(name, sca->ifp->if_xname, len); + DPRINTF("name='%s/%db' created sca=%p scb=%p\n", name, unit, sca, scb); /* Tell the world, that we are ready to rock. */ sca->ifp->if_drv_flags |= IFF_DRV_RUNNING; - if_link_state_change(sca->ifp, LINK_STATE_UP); scb->ifp->if_drv_flags |= IFF_DRV_RUNNING; + if_link_state_change(sca->ifp, LINK_STATE_UP); if_link_state_change(scb->ifp, LINK_STATE_UP); return (0); } -static void -epair_drain_rings(struct epair_softc *sc) -{ - int ridx; - struct mbuf *m; - - for (ridx = 0; ridx < 2; ridx++) { - for (int i = 0; i < sc->num_queues; i++) { - struct epair_queue *q = &sc->queues[i]; - do { - m = buf_ring_dequeue_sc(q->rxring[ridx]); - if (m == NULL) - break; - m_freem(m); - } while (1); - } - } -} - static int epair_clone_destroy(struct if_clone *ifc, struct ifnet *ifp) { @@ -713,6 +932,8 @@ epair_clone_destroy(struct if_clone *ifc, struct ifnet *ifp) *** 198 LINES SKIPPED ***