Date: Mon, 30 Jun 2014 04:38:29 +0000 (UTC) From: Adrian Chadd <adrian@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r268029 - head/sys/dev/ixgbe Message-ID: <201406300438.s5U4cTVF044431@svn.freebsd.org>
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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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