diff options
author | Matt Macy <mmacy@FreeBSD.org> | 2020-12-19 01:08:33 +0000 |
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committer | Matt Macy <mmacy@FreeBSD.org> | 2021-01-07 22:07:35 +0000 |
commit | 81be655266fac2b333e25f386f32c9bcd17f523d (patch) | |
tree | 187ff1643f400c37da4c007193297d3d22c0c9a3 /sys/net/iflib.c | |
parent | 11403bdeb4158531af36bc7c51cbbba27deb69b1 (diff) | |
download | src-81be655266fac2b333e25f386f32c9bcd17f523d.tar.gz src-81be655266fac2b333e25f386f32c9bcd17f523d.zip |
Diffstat (limited to 'sys/net/iflib.c')
-rw-r--r-- | sys/net/iflib.c | 94 |
1 files changed, 62 insertions, 32 deletions
diff --git a/sys/net/iflib.c b/sys/net/iflib.c index 5db925fef05f..cc401a5db24d 100644 --- a/sys/net/iflib.c +++ b/sys/net/iflib.c @@ -585,6 +585,10 @@ SYSCTL_INT(_net_iflib, OID_AUTO, min_tx_latency, CTLFLAG_RW, static int iflib_no_tx_batch = 0; SYSCTL_INT(_net_iflib, OID_AUTO, no_tx_batch, CTLFLAG_RW, &iflib_no_tx_batch, 0, "minimize transmit latency at the possible expense of throughput"); +static int iflib_timer_default = 1000; +SYSCTL_INT(_net_iflib, OID_AUTO, timer_default, CTLFLAG_RW, + &iflib_timer_default, 0, "number of ticks between iflib_timer calls"); + #if IFLIB_DEBUG_COUNTERS @@ -2293,7 +2297,7 @@ iflib_timer(void *arg) ** can be done without the lock because its RO ** and the HUNG state will be static if set. */ - if (this_tick - txq->ift_last_timer_tick >= hz / 2) { + if (this_tick - txq->ift_last_timer_tick >= iflib_timer_default) { txq->ift_last_timer_tick = this_tick; IFDI_TIMER(ctx, txq->ift_id); if ((txq->ift_qstatus == IFLIB_QUEUE_HUNG) && @@ -2303,7 +2307,8 @@ iflib_timer(void *arg) if (txq->ift_qstatus != IFLIB_QUEUE_IDLE && ifmp_ring_is_stalled(txq->ift_br)) { - KASSERT(ctx->ifc_link_state == LINK_STATE_UP, ("queue can't be marked as hung if interface is down")); + KASSERT(ctx->ifc_link_state == LINK_STATE_UP, + ("queue can't be marked as hung if interface is down")); txq->ift_qstatus = IFLIB_QUEUE_HUNG; } txq->ift_cleaned_prev = txq->ift_cleaned; @@ -2314,7 +2319,8 @@ iflib_timer(void *arg) sctx->isc_pause_frames = 0; if (if_getdrvflags(ctx->ifc_ifp) & IFF_DRV_RUNNING) - callout_reset_on(&txq->ift_timer, hz / 2, iflib_timer, txq, txq->ift_timer.c_cpu); + callout_reset_on(&txq->ift_timer, iflib_timer_default, iflib_timer, + txq, txq->ift_timer.c_cpu); return; hung: @@ -2426,7 +2432,7 @@ done: IFDI_INTR_ENABLE(ctx); txq = ctx->ifc_txqs; for (i = 0; i < sctx->isc_ntxqsets; i++, txq++) - callout_reset_on(&txq->ift_timer, hz/2, iflib_timer, txq, + callout_reset_on(&txq->ift_timer, iflib_timer_default, iflib_timer, txq, txq->ift_timer.c_cpu); } @@ -3001,26 +3007,37 @@ txq_max_rs_deferred(iflib_txq_t txq) /* XXX we should be setting this to something other than zero */ #define RECLAIM_THRESH(ctx) ((ctx)->ifc_sctx->isc_tx_reclaim_thresh) -#define MAX_TX_DESC(ctx) max((ctx)->ifc_softc_ctx.isc_tx_tso_segments_max, \ +#define MAX_TX_DESC(ctx) MAX((ctx)->ifc_softc_ctx.isc_tx_tso_segments_max, \ (ctx)->ifc_softc_ctx.isc_tx_nsegments) static inline bool -iflib_txd_db_check(if_ctx_t ctx, iflib_txq_t txq, int ring, qidx_t in_use) +iflib_txd_db_check(iflib_txq_t txq, int ring) { + if_ctx_t ctx = txq->ift_ctx; qidx_t dbval, max; - bool rang; - rang = false; - max = TXQ_MAX_DB_DEFERRED(txq, in_use); - if (ring || txq->ift_db_pending >= max) { + max = TXQ_MAX_DB_DEFERRED(txq, txq->ift_in_use); + + /* force || threshold exceeded || at the edge of the ring */ + if (ring || (txq->ift_db_pending >= max) || (TXQ_AVAIL(txq) <= MAX_TX_DESC(ctx) + 2)) { + + /* + * 'npending' is used if the card's doorbell is in terms of the number of descriptors + * pending flush (BRCM). 'pidx' is used in cases where the card's doorbeel uses the + * producer index explicitly (INTC). + */ dbval = txq->ift_npending ? txq->ift_npending : txq->ift_pidx; bus_dmamap_sync(txq->ift_ifdi->idi_tag, txq->ift_ifdi->idi_map, BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE); ctx->isc_txd_flush(ctx->ifc_softc, txq->ift_id, dbval); + + /* + * Absent bugs there are zero packets pending so reset pending counts to zero. + */ txq->ift_db_pending = txq->ift_npending = 0; - rang = true; + return (true); } - return (rang); + return (false); } #ifdef PKT_DEBUG @@ -3481,6 +3498,7 @@ defrag: MPASS(pi.ipi_new_pidx != pidx); MPASS(ndesc > 0); txq->ift_in_use += ndesc; + txq->ift_db_pending += ndesc; /* * We update the last software descriptor again here because there may @@ -3647,8 +3665,8 @@ iflib_txq_drain(struct ifmp_ring *r, uint32_t cidx, uint32_t pidx) if_ctx_t ctx = txq->ift_ctx; if_t ifp = ctx->ifc_ifp; struct mbuf *m, **mp; - int avail, bytes_sent, consumed, count, err, i, in_use_prev; - int mcast_sent, pkt_sent, reclaimed, txq_avail; + int avail, bytes_sent, skipped, count, err, i; + int mcast_sent, pkt_sent, reclaimed; bool do_prefetch, rang, ring; if (__predict_false(!(if_getdrvflags(ifp) & IFF_DRV_RUNNING) || @@ -3657,9 +3675,13 @@ iflib_txq_drain(struct ifmp_ring *r, uint32_t cidx, uint32_t pidx) return (0); } reclaimed = iflib_completed_tx_reclaim(txq, RECLAIM_THRESH(ctx)); - rang = iflib_txd_db_check(ctx, txq, reclaimed, txq->ift_in_use); + rang = iflib_txd_db_check(txq, reclaimed && txq->ift_db_pending); avail = IDXDIFF(pidx, cidx, r->size); + if (__predict_false(ctx->ifc_flags & IFC_QFLUSH)) { + /* + * The driver is unloading so we need to free all pending packets. + */ DBG_COUNTER_INC(txq_drain_flushing); for (i = 0; i < avail; i++) { if (__predict_true(r->items[(cidx + i) & (r->size-1)] != (void *)txq)) @@ -3677,9 +3699,13 @@ iflib_txq_drain(struct ifmp_ring *r, uint32_t cidx, uint32_t pidx) DBG_COUNTER_INC(txq_drain_oactive); return (0); } + + /* + * If we've reclaimed any packets this queue cannot be hung. + */ if (reclaimed) txq->ift_qstatus = IFLIB_QUEUE_IDLE; - consumed = mcast_sent = bytes_sent = pkt_sent = 0; + skipped = mcast_sent = bytes_sent = pkt_sent = 0; count = MIN(avail, TX_BATCH_SIZE); #ifdef INVARIANTS if (iflib_verbose_debug) @@ -3687,54 +3713,57 @@ iflib_txq_drain(struct ifmp_ring *r, uint32_t cidx, uint32_t pidx) avail, ctx->ifc_flags, TXQ_AVAIL(txq)); #endif do_prefetch = (ctx->ifc_flags & IFC_PREFETCH); - txq_avail = TXQ_AVAIL(txq); err = 0; - for (i = 0; i < count && txq_avail > MAX_TX_DESC(ctx) + 2; i++) { + for (i = 0; i < count && TXQ_AVAIL(txq) >= MAX_TX_DESC(ctx) + 2; i++) { int rem = do_prefetch ? count - i : 0; mp = _ring_peek_one(r, cidx, i, rem); MPASS(mp != NULL && *mp != NULL); + + /* + * Completion interrupts will use the address of the txq + * as a sentinel to enqueue _something_ in order to acquire + * the lock on the mp_ring (there's no direct lock call). + * We obviously whave to check for these sentinel cases + * and skip them. + */ if (__predict_false(*mp == (struct mbuf *)txq)) { - consumed++; + skipped++; continue; } - in_use_prev = txq->ift_in_use; err = iflib_encap(txq, mp); if (__predict_false(err)) { /* no room - bail out */ if (err == ENOBUFS) break; - consumed++; + skipped++; /* we can't send this packet - skip it */ continue; } - consumed++; pkt_sent++; m = *mp; DBG_COUNTER_INC(tx_sent); bytes_sent += m->m_pkthdr.len; mcast_sent += !!(m->m_flags & M_MCAST); - txq_avail = TXQ_AVAIL(txq); - txq->ift_db_pending += (txq->ift_in_use - in_use_prev); - ETHER_BPF_MTAP(ifp, m); if (__predict_false(!(ifp->if_drv_flags & IFF_DRV_RUNNING))) break; - rang = iflib_txd_db_check(ctx, txq, false, in_use_prev); + ETHER_BPF_MTAP(ifp, m); + rang = iflib_txd_db_check(txq, false); } /* deliberate use of bitwise or to avoid gratuitous short-circuit */ - ring = rang ? false : (iflib_min_tx_latency | err) || (TXQ_AVAIL(txq) < MAX_TX_DESC(ctx)); - iflib_txd_db_check(ctx, txq, ring, txq->ift_in_use); + ring = rang ? false : (iflib_min_tx_latency | err); + iflib_txd_db_check(txq, ring); if_inc_counter(ifp, IFCOUNTER_OBYTES, bytes_sent); if_inc_counter(ifp, IFCOUNTER_OPACKETS, pkt_sent); if (mcast_sent) if_inc_counter(ifp, IFCOUNTER_OMCASTS, mcast_sent); #ifdef INVARIANTS if (iflib_verbose_debug) - printf("consumed=%d\n", consumed); + printf("consumed=%d\n", skipped + pkt_sent); #endif - return (consumed); + return (skipped + pkt_sent); } static uint32_t @@ -3907,7 +3936,7 @@ _task_fn_admin(void *context) } IFDI_UPDATE_ADMIN_STATUS(ctx); for (txq = ctx->ifc_txqs, i = 0; i < sctx->isc_ntxqsets; i++, txq++) { - callout_reset_on(&txq->ift_timer, hz / 2, iflib_timer, txq, + callout_reset_on(&txq->ift_timer, iflib_timer_default, iflib_timer, txq, txq->ift_timer.c_cpu); } IFDI_LINK_INTR_ENABLE(ctx); @@ -5301,6 +5330,7 @@ iflib_device_iov_add_vf(device_t dev, uint16_t vfnum, const nvlist_t *params) static int iflib_module_init(void) { + iflib_timer_default = hz / 2; return (0); } @@ -6861,7 +6891,7 @@ iflib_debugnet_transmit(if_t ifp, struct mbuf *m) txq = &ctx->ifc_txqs[0]; error = iflib_encap(txq, &m); if (error == 0) - (void)iflib_txd_db_check(ctx, txq, true, txq->ift_in_use); + (void)iflib_txd_db_check(txq, true); return (error); } |