Date: Sun, 29 Jun 2014 21:39:32 -0700 From: Adrian Chadd <adrian@freebsd.org> To: "src-committers@freebsd.org" <src-committers@freebsd.org>, "svn-src-all@freebsd.org" <svn-src-all@freebsd.org>, "svn-src-head@freebsd.org" <svn-src-head@freebsd.org> Subject: Re: svn commit: r268029 - head/sys/dev/ixgbe Message-ID: <CAJ-Vmo=8gU%2B%2BTvKpO5ShzRcD3AHgyRkmf%2BHw1y05%2Bd0qsHhh3w@mail.gmail.com> In-Reply-To: <201406300438.s5U4cTVF044431@svn.freebsd.org> References: <201406300438.s5U4cTVF044431@svn.freebsd.org>
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Reviewed by: jfv, gnn On 29 June 2014 21:38, Adrian Chadd <adrian@freebsd.org> wrote: > Author: adrian > Date: Mon Jun 30 04:38:29 2014 > New Revision: 268029 > URL: http://svnweb.freebsd.org/changeset/base/268029 > > Log: > Add initial RSS awareness to the ixgbe(4) driver. > > The ixgbe(4) hardware is capable of RSS hashing RX packets and doing RSS > queue selection for up to 8 queues. > > However, even if multi-queue is enabled for ixgbe(4), the RX path doesn't use > the RSS flowid from the received descriptor. It just uses the MSIX queue id. > > This patch does a handful of things if RSS is enabled: > > * Instead of using a random key at boot, fetch the RSS key from the RSS code > and program that in to the RSS redirection table. > > That whole chunk of code should be double checked for endian correctness. > > * Use the RSS queue mapping to CPU ID to figure out where to thread pin > the RX swi thread and the taskqueue threads for each queue. > > * The software queue is now really an "RSS bucket". > > * When programming the RSS indirection table, use the RSS code to > figure out which RSS bucket each slot in the indirection table maps > to. > > * When transmitting, use the flowid RSS mapping if the mbuf has > an RSS aware hash. The existing method wasn't guaranteed to align > correctly with the destination RSS bucket (and thus CPU ID.) > > This code warns if the number of RSS buckets isn't the same as the > automatically configured number of hardware queues. The administrator > will have to tweak one of them for better performance. > > There's currently no way to re-balance the RSS indirection table after > startup. I'll worry about that later. > > Additionally, it may be worthwhile to always use the full 32 bit flowid if > multi-queue is enabled. It'll make things like lagg(4) behave better with > respect to traffic distribution. > > Modified: > head/sys/dev/ixgbe/ixgbe.c > > Modified: head/sys/dev/ixgbe/ixgbe.c > ============================================================================== > --- head/sys/dev/ixgbe/ixgbe.c Mon Jun 30 04:34:59 2014 (r268028) > +++ head/sys/dev/ixgbe/ixgbe.c Mon Jun 30 04:38:29 2014 (r268029) > @@ -35,8 +35,13 @@ > > #include "opt_inet.h" > #include "opt_inet6.h" > +#include "opt_rss.h" > #include "ixgbe.h" > > +#ifdef RSS > +#include <netinet/in_rss.h> > +#endif > + > /********************************************************************* > * Set this to one to display debug statistics > *********************************************************************/ > @@ -809,12 +814,33 @@ ixgbe_mq_start(struct ifnet *ifp, struct > struct ix_queue *que; > struct tx_ring *txr; > int i, err = 0; > +#ifdef RSS > + uint32_t bucket_id; > +#endif > > /* Which queue to use */ > - if ((m->m_flags & M_FLOWID) != 0) > - i = m->m_pkthdr.flowid % adapter->num_queues; > - else > + /* > + * When doing RSS, map it to the same outbound queue > + * as the incoming flow would be mapped to. > + * > + * If everything is setup correctly, it should be the > + * same bucket that the current CPU we're on is. > + */ > + if ((m->m_flags & M_FLOWID) != 0) { > +#ifdef RSS > + if (rss_hash2bucket(m->m_pkthdr.flowid, > + M_HASHTYPE_GET(m), &bucket_id) == 0) { > + /* XXX TODO: spit out something if bucket_id > num_queues? */ > + i = bucket_id % adapter->num_queues; > + } else { > +#endif > + i = m->m_pkthdr.flowid % adapter->num_queues; > +#ifdef RSS > + } > +#endif > + } else { > i = curcpu % adapter->num_queues; > + } > > txr = &adapter->tx_rings[i]; > que = &adapter->queues[i]; > @@ -2338,6 +2364,31 @@ ixgbe_allocate_msix(struct adapter *adap > struct ix_queue *que = adapter->queues; > struct tx_ring *txr = adapter->tx_rings; > int error, rid, vector = 0; > + int cpu_id; > + > +#ifdef RSS > + /* > + * If we're doing RSS, the number of queues needs to > + * match the number of RSS buckets that are configured. > + * > + * + If there's more queues than RSS buckets, we'll end > + * up with queues that get no traffic. > + * > + * + If there's more RSS buckets than queues, we'll end > + * up having multiple RSS buckets map to the same queue, > + * so there'll be some contention. > + */ > + if (adapter->num_queues != rss_getnumbuckets()) { > + device_printf(dev, > + "%s: number of queues (%d) != number of RSS buckets (%d)" > + "; performance will be impacted.\n", > + __func__, > + adapter->num_queues, > + rss_getnumbuckets()); > + } > +#endif > + > + > > for (int i = 0; i < adapter->num_queues; i++, vector++, que++, txr++) { > rid = vector + 1; > @@ -2362,12 +2413,37 @@ ixgbe_allocate_msix(struct adapter *adap > #endif > que->msix = vector; > adapter->que_mask |= (u64)(1 << que->msix); > +#ifdef RSS > /* > - ** Bind the msix vector, and thus the > - ** ring to the corresponding cpu. > - */ > + * The queue ID is used as the RSS layer bucket ID. > + * We look up the queue ID -> RSS CPU ID and select > + * that. > + */ > + cpu_id = rss_getcpu(i % rss_getnumbuckets()); > +#else > + /* > + * Bind the msix vector, and thus the > + * rings to the corresponding cpu. > + * > + * This just happens to match the default RSS round-robin > + * bucket -> queue -> CPU allocation. > + */ > if (adapter->num_queues > 1) > - bus_bind_intr(dev, que->res, i); > + cpu_id = i; > +#endif > + if (adapter->num_queues > 1) > + bus_bind_intr(dev, que->res, cpu_id); > + > +#ifdef RSS > + device_printf(dev, > + "Bound RSS bucket %d to CPU %d\n", > + i, cpu_id); > +#else > + device_printf(dev, > + "Bound queue %d to cpu %d\n", > + i, cpu_id); > +#endif > + > > #ifndef IXGBE_LEGACY_TX > TASK_INIT(&txr->txq_task, 0, ixgbe_deferred_mq_start, txr); > @@ -2375,8 +2451,16 @@ ixgbe_allocate_msix(struct adapter *adap > TASK_INIT(&que->que_task, 0, ixgbe_handle_que, que); > que->tq = taskqueue_create_fast("ixgbe_que", M_NOWAIT, > taskqueue_thread_enqueue, &que->tq); > +#ifdef RSS > + taskqueue_start_threads_pinned(&que->tq, 1, PI_NET, > + cpu_id, > + "%s (bucket %d)", > + device_get_nameunit(adapter->dev), > + cpu_id); > +#else > taskqueue_start_threads(&que->tq, 1, PI_NET, "%s que", > device_get_nameunit(adapter->dev)); > +#endif > } > > /* and Link */ > @@ -2450,6 +2534,11 @@ ixgbe_setup_msix(struct adapter *adapter > > /* Figure out a reasonable auto config value */ > queues = (mp_ncpus > (msgs-1)) ? (msgs-1) : mp_ncpus; > +#ifdef RSS > + /* If we're doing RSS, clamp at the number of RSS buckets */ > + if (queues > rss_getnumbuckets()) > + queues = rss_getnumbuckets(); > +#endif > > if (ixgbe_num_queues != 0) > queues = ixgbe_num_queues; > @@ -4107,6 +4196,65 @@ fail: > return (ENOBUFS); > } > > +static void > +ixgbe_initialise_rss_mapping(struct adapter *adapter) > +{ > + struct ixgbe_hw *hw = &adapter->hw; > + uint32_t reta; > + int i, j, queue_id; > + uint32_t rss_key[10]; > + uint32_t mrqc; > + > + /* Setup RSS */ > + reta = 0; > + > +#ifdef RSS > + /* Fetch the configured RSS key */ > + rss_getkey((uint8_t *) &rss_key); > +#else > + /* set up random bits */ > + arc4rand(&rss_key, sizeof(rss_key), 0); > +#endif > + > + /* Set up the redirection table */ > + for (i = 0, j = 0; i < 128; i++, j++) { > + if (j == adapter->num_queues) j = 0; > +#ifdef RSS > + /* > + * Fetch the RSS bucket id for the given indirection entry. > + * Cap it at the number of configured buckets (which is > + * num_queues.) > + */ > + queue_id = rss_get_indirection_to_bucket(i); > + queue_id = queue_id % adapter->num_queues; > +#else > + queue_id = (j * 0x11); > +#endif > + /* XXX endian? */ > + reta = (reta << 8) | queue_id; > + if ((i & 3) == 3) > + IXGBE_WRITE_REG(hw, IXGBE_RETA(i >> 2), reta); > + } > + > + /* Now fill our hash function seeds */ > + for (int i = 0; i < 10; i++) > + IXGBE_WRITE_REG(hw, IXGBE_RSSRK(i), rss_key[i]); > + > + /* Perform hash on these packet types */ > + mrqc = IXGBE_MRQC_RSSEN > + | IXGBE_MRQC_RSS_FIELD_IPV4 > + | IXGBE_MRQC_RSS_FIELD_IPV4_TCP > + | IXGBE_MRQC_RSS_FIELD_IPV4_UDP > + | IXGBE_MRQC_RSS_FIELD_IPV6_EX_TCP > + | IXGBE_MRQC_RSS_FIELD_IPV6_EX > + | IXGBE_MRQC_RSS_FIELD_IPV6 > + | IXGBE_MRQC_RSS_FIELD_IPV6_TCP > + | IXGBE_MRQC_RSS_FIELD_IPV6_UDP > + | IXGBE_MRQC_RSS_FIELD_IPV6_EX_UDP; > + IXGBE_WRITE_REG(hw, IXGBE_MRQC, mrqc); > +} > + > + > /********************************************************************* > * > * Setup receive registers and features. > @@ -4123,7 +4271,7 @@ ixgbe_initialize_receive_units(struct ad > struct ixgbe_hw *hw = &adapter->hw; > struct ifnet *ifp = adapter->ifp; > u32 bufsz, rxctrl, fctrl, srrctl, rxcsum; > - u32 reta, mrqc = 0, hlreg, random[10]; > + u32 hlreg; > > > /* > @@ -4195,39 +4343,9 @@ ixgbe_initialize_receive_units(struct ad > > rxcsum = IXGBE_READ_REG(hw, IXGBE_RXCSUM); > > - /* Setup RSS */ > - if (adapter->num_queues > 1) { > - int i, j; > - reta = 0; > - > - /* set up random bits */ > - arc4rand(&random, sizeof(random), 0); > - > - /* Set up the redirection table */ > - for (i = 0, j = 0; i < 128; i++, j++) { > - if (j == adapter->num_queues) j = 0; > - reta = (reta << 8) | (j * 0x11); > - if ((i & 3) == 3) > - IXGBE_WRITE_REG(hw, IXGBE_RETA(i >> 2), reta); > - } > - > - /* Now fill our hash function seeds */ > - for (int i = 0; i < 10; i++) > - IXGBE_WRITE_REG(hw, IXGBE_RSSRK(i), random[i]); > - > - /* Perform hash on these packet types */ > - mrqc = IXGBE_MRQC_RSSEN > - | IXGBE_MRQC_RSS_FIELD_IPV4 > - | IXGBE_MRQC_RSS_FIELD_IPV4_TCP > - | IXGBE_MRQC_RSS_FIELD_IPV4_UDP > - | IXGBE_MRQC_RSS_FIELD_IPV6_EX_TCP > - | IXGBE_MRQC_RSS_FIELD_IPV6_EX > - | IXGBE_MRQC_RSS_FIELD_IPV6 > - | IXGBE_MRQC_RSS_FIELD_IPV6_TCP > - | IXGBE_MRQC_RSS_FIELD_IPV6_UDP > - | IXGBE_MRQC_RSS_FIELD_IPV6_EX_UDP; > - IXGBE_WRITE_REG(hw, IXGBE_MRQC, mrqc); > + ixgbe_initialise_rss_mapping(adapter); > > + if (adapter->num_queues > 1) { > /* RSS and RX IPP Checksum are mutually exclusive */ > rxcsum |= IXGBE_RXCSUM_PCSD; > } > @@ -4400,6 +4518,7 @@ ixgbe_rxeof(struct ix_queue *que) > u16 count = rxr->process_limit; > union ixgbe_adv_rx_desc *cur; > struct ixgbe_rx_buf *rbuf, *nbuf; > + u16 pkt_info; > > IXGBE_RX_LOCK(rxr); > > @@ -4424,6 +4543,7 @@ ixgbe_rxeof(struct ix_queue *que) > > cur = &rxr->rx_base[i]; > staterr = le32toh(cur->wb.upper.status_error); > + pkt_info = le16toh(cur->wb.lower.lo_dword.hs_rss.pkt_info); > > if ((staterr & IXGBE_RXD_STAT_DD) == 0) > break; > @@ -4556,9 +4676,44 @@ ixgbe_rxeof(struct ix_queue *que) > if ((ifp->if_capenable & IFCAP_RXCSUM) != 0) > ixgbe_rx_checksum(staterr, sendmp, ptype); > #if __FreeBSD_version >= 800000 > +#ifdef RSS > + sendmp->m_pkthdr.flowid = > + le32toh(cur->wb.lower.hi_dword.rss); > + sendmp->m_flags |= M_FLOWID; > + switch (pkt_info & IXGBE_RXDADV_RSSTYPE_MASK) { > + case IXGBE_RXDADV_RSSTYPE_IPV4_TCP: > + M_HASHTYPE_SET(sendmp, M_HASHTYPE_RSS_TCP_IPV4); > + break; > + case IXGBE_RXDADV_RSSTYPE_IPV4: > + M_HASHTYPE_SET(sendmp, M_HASHTYPE_RSS_IPV4); > + break; > + case IXGBE_RXDADV_RSSTYPE_IPV6_TCP: > + M_HASHTYPE_SET(sendmp, M_HASHTYPE_RSS_TCP_IPV6); > + break; > + case IXGBE_RXDADV_RSSTYPE_IPV6_EX: > + M_HASHTYPE_SET(sendmp, M_HASHTYPE_RSS_IPV6_EX); > + break; > + case IXGBE_RXDADV_RSSTYPE_IPV6: > + M_HASHTYPE_SET(sendmp, M_HASHTYPE_RSS_IPV6); > + break; > + case IXGBE_RXDADV_RSSTYPE_IPV6_TCP_EX: > + M_HASHTYPE_SET(sendmp, M_HASHTYPE_RSS_TCP_IPV6_EX); > + break; > + /* XXX no UDP support in RSS just yet */ > +#ifdef notyet > + case IGXBE_RXDADV_RSSTYPE_IPV4_UDP: > + case IGXBE_RXDADV_RSSTYPE_IPV6_UDP: > + case IGXBE_RXDADV_RSSTYPE_IPV6_UDP_EX: > +#endif /* notyet */ > + default: > + /* XXX fallthrough */ > + M_HASHTYPE_SET(sendmp, M_HASHTYPE_NONE); > + } > +#else /* RSS */ > sendmp->m_pkthdr.flowid = que->msix; > sendmp->m_flags |= M_FLOWID; > -#endif > +#endif /* RSS */ > +#endif /* FreeBSD_version */ > } > next_desc: > bus_dmamap_sync(rxr->rxdma.dma_tag, rxr->rxdma.dma_map, >
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