Date: Mon, 30 Jun 2014 16:56:01 +0200 From: Luigi Rizzo <rizzo@iet.unipi.it> To: Adrian Chadd <adrian@freebsd.org> Cc: "svn-src-head@freebsd.org" <svn-src-head@freebsd.org>, "svn-src-all@freebsd.org" <svn-src-all@freebsd.org>, "src-committers@freebsd.org" <src-committers@freebsd.org> Subject: Re: svn commit: r268028 - head/sys/dev/e1000 Message-ID: <CA%2BhQ2%2BgOPS6XKeWSNXO2BVkpk%2B82tjvSZ_nWgpwsFgPpEo%2BeNg@mail.gmail.com> In-Reply-To: <CAJ-Vmom7fsk67Q6sWgwu=GOOn59Zu5uGXeNG%2BYt2hP-edN%2BpvQ@mail.gmail.com> References: <201406300434.s5U4YxGY043870@svn.freebsd.org> <CAJ-Vmom7fsk67Q6sWgwu=GOOn59Zu5uGXeNG%2BYt2hP-edN%2BpvQ@mail.gmail.com>
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I am getting the following error while compiling with gcc:
cc1: warnings being treated as errors
/usr/home/luigi/FreeBSD/head/sys/dev/e1000/if_igb.c: In function
'igb_attach':
/usr/home/luigi/FreeBSD/head/sys/dev/e1000/if_igb.c:2461: warning: 'cpu_id'
may be used uninitialized in this function
/usr/home/luigi/FreeBSD/head/sys/dev/e1000/if_igb.c:2461: note: 'cpu_id'
was declared here
(the code is correct, apparently gcc cannot understand that).
For compatibility i'd throw in an explicit initialization,
however it might be worthwhile rewriting the code with a single
if (adapter->num_queues > 1) { ...} block within the for(),
and also using only one #ifdef RSS -- the other places only
differ in the string passed to diagnostics or comments.
cheers
luigi
the code detect that
cpu_id is only used when
On Mon, Jun 30, 2014 at 6:39 AM, Adrian Chadd <adrian@freebsd.org> wrote:
> Reviewed by: jfv, gnn
>
> On 29 June 2014 21:34, Adrian Chadd <adrian@freebsd.org> wrote:
> > Author: adrian
> > Date: Mon Jun 30 04:34:59 2014
> > New Revision: 268028
> > URL: http://svnweb.freebsd.org/changeset/base/268028
> >
> > Log:
> > Add initial RSS awareness to the igb(4) driver.
> >
> > The igb(4) hardware is capable of RSS hashing RX packets and doing RSS
> > queue selection for up to 8 queues. (I believe some hardware is
> limited
> > to 4 queues, but I haven't tested on that.)
> >
> > However, even if multi-queue is enabled for igb(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/e1000/if_igb.c
> >
> > Modified: head/sys/dev/e1000/if_igb.c
> >
> ==============================================================================
> > --- head/sys/dev/e1000/if_igb.c Mon Jun 30 04:26:29 2014 (r268027)
> > +++ head/sys/dev/e1000/if_igb.c Mon Jun 30 04:34:59 2014 (r268028)
> > @@ -35,6 +35,7 @@
> >
> > #include "opt_inet.h"
> > #include "opt_inet6.h"
> > +#include "opt_rss.h"
> >
> > #ifdef HAVE_KERNEL_OPTION_HEADERS
> > #include "opt_device_polling.h"
> > @@ -84,6 +85,9 @@
> > #include <netinet/tcp.h>
> > #include <netinet/tcp_lro.h>
> > #include <netinet/udp.h>
> > +#ifdef RSS
> > +#include <netinet/in_rss.h>
> > +#endif
> >
> > #include <machine/in_cksum.h>
> > #include <dev/led/led.h>
> > @@ -967,12 +971,33 @@ igb_mq_start(struct ifnet *ifp, struct m
> > struct igb_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];
> >
> > @@ -2433,11 +2458,34 @@ igb_allocate_msix(struct adapter *adapte
> > device_t dev = adapter->dev;
> > struct igb_queue *que = adapter->queues;
> > int error, rid, vector = 0;
> > + int cpu_id;
> >
> > /* Be sure to start with all interrupts disabled */
> > E1000_WRITE_REG(&adapter->hw, E1000_IMC, ~0);
> > E1000_WRITE_FLUSH(&adapter->hw);
> >
> > +#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++) {
> > rid = vector +1;
> > que->res = bus_alloc_resource_any(dev,
> > @@ -2464,19 +2512,42 @@ igb_allocate_msix(struct adapter *adapte
> > que->eims = E1000_EICR_TX_QUEUE0 << i;
> > else
> > que->eims = 1 << vector;
> > +
> > +#ifdef RSS
> > /*
> > - ** Bind the msix vector, and thus the
> > - ** rings 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) {
> > if (igb_last_bind_cpu < 0)
> > igb_last_bind_cpu = CPU_FIRST();
> > - bus_bind_intr(dev, que->res, igb_last_bind_cpu);
> > + cpu_id = igb_last_bind_cpu;
> > + }
> > +#endif
> > +
> > + if (adapter->num_queues > 1) {
> > + bus_bind_intr(dev, que->res, cpu_id);
> > +#ifdef RSS
> > + device_printf(dev,
> > + "Bound queue %d to RSS bucket %d\n",
> > + i, cpu_id);
> > +#else
> > device_printf(dev,
> > "Bound queue %d to cpu %d\n",
> > - i,igb_last_bind_cpu);
> > - igb_last_bind_cpu = CPU_NEXT(igb_last_bind_cpu);
> > + i, cpu_id);
> > +#endif
> > }
> > +
> > #ifndef IGB_LEGACY_TX
> > TASK_INIT(&que->txr->txq_task, 0, igb_deferred_mq_start,
> > que->txr);
> > @@ -2485,8 +2556,34 @@ igb_allocate_msix(struct adapter *adapte
> > TASK_INIT(&que->que_task, 0, igb_handle_que, que);
> > que->tq = taskqueue_create("igb_que", M_NOWAIT,
> > taskqueue_thread_enqueue, &que->tq);
> > - taskqueue_start_threads(&que->tq, 1, PI_NET, "%s que",
> > - device_get_nameunit(adapter->dev));
> > + if (adapter->num_queues > 1) {
> > + /*
> > + * Only pin the taskqueue thread to a CPU if
> > + * RSS is in use.
> > + *
> > + * This again just happens to match the default
> RSS
> > + * round-robin bucket -> queue -> CPU allocation.
> > + */
> > +#ifdef RSS
> > + taskqueue_start_threads_pinned(&que->tq, 1,
> PI_NET,
> > + cpu_id,
> > + "%s que (bucket %d)",
> > + device_get_nameunit(adapter->dev),
> > + cpu_id);
> > +#else
> > + taskqueue_start_threads(&que->tq, 1, PI_NET,
> > + "%s que (qid %d)",
> > + device_get_nameunit(adapter->dev),
> > + cpu_id);
> > +#endif
> > + } else {
> > + taskqueue_start_threads(&que->tq, 1, PI_NET, "%s
> que",
> > + device_get_nameunit(adapter->dev));
> > + }
> > +
> > + /* Finally update the last bound CPU id */
> > + if (adapter->num_queues > 1)
> > + igb_last_bind_cpu = CPU_NEXT(igb_last_bind_cpu);
> > }
> >
> > /* And Link */
> > @@ -2763,6 +2860,13 @@ igb_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
> > +
> > +
> > /* Manual override */
> > if (igb_num_queues != 0)
> > queues = igb_num_queues;
> > @@ -4455,6 +4559,99 @@ fail:
> > return (ENOBUFS);
> > }
> >
> > +/*
> > + * Initialise the RSS mapping for NICs that support multiple transmit/
> > + * receive rings.
> > + */
> > +static void
> > +igb_initialise_rss_mapping(struct adapter *adapter)
> > +{
> > + struct e1000_hw *hw = &adapter->hw;
> > + int i;
> > + int queue_id;
> > +
> > + u32 rss_key[10], mrqc, shift = 0;
> > + union igb_reta {
> > + u32 dword;
> > + u8 bytes[4];
> > + } reta;
> > +
> > + /* XXX? */
> > + if (adapter->hw.mac.type == e1000_82575)
> > + shift = 6;
> > +
> > + /*
> > + * The redirection table controls which destination
> > + * queue each bucket redirects traffic to.
> > + * Each DWORD represents four queues, with the LSB
> > + * being the first queue in the DWORD.
> > + *
> > + * This just allocates buckets to queues using round-robin
> > + * allocation.
> > + *
> > + * NOTE: It Just Happens to line up with the default
> > + * RSS allocation method.
> > + */
> > +
> > + /* Warning FM follows */
> > + for (i = 0; i < 128; i++) {
> > +#ifdef RSS
> > + queue_id = rss_get_indirection_to_bucket(i);
> > + /*
> > + * If we have more queues than buckets, we'll
> > + * end up mapping buckets to a subset of the
> > + * queues.
> > + *
> > + * If we have more buckets than queues, we'll
> > + * end up instead assigning multiple buckets
> > + * to queues.
> > + *
> > + * Both are suboptimal, but we need to handle
> > + * the case so we don't go out of bounds
> > + * indexing arrays and such.
> > + */
> > + queue_id = queue_id % adapter->num_queues;
> > +#else
> > + queue_id = (i % adapter->num_queues);
> > +#endif
> > + reta.bytes[i & 3] = queue_id << shift;
> > +
> > + if ((i & 3) == 3)
> > + E1000_WRITE_REG(hw,
> > + E1000_RETA(i >> 2), reta.dword);
> > + }
> > +
> > +
> > + /* Now fill in hash table */
> > +
> > + /* XXX This means RSS enable + 8 queues for my igb (82580.) */
> > + mrqc = E1000_MRQC_ENABLE_RSS_4Q;
> > +
> > +#ifdef RSS
> > + /* XXX ew typecasting */
> > + rss_getkey((uint8_t *) &rss_key);
> > +#else
> > + arc4rand(&rss_key, sizeof(rss_key), 0);
> > +#endif
> > + for (i = 0; i < 10; i++)
> > + E1000_WRITE_REG_ARRAY(hw,
> > + E1000_RSSRK(0), i, rss_key[i]);
> > +
> > + /*
> > + * Configure the RSS fields to hash upon.
> > + */
> > + mrqc |= (E1000_MRQC_RSS_FIELD_IPV4 |
> > + E1000_MRQC_RSS_FIELD_IPV4_TCP);
> > + mrqc |= (E1000_MRQC_RSS_FIELD_IPV6 |
> > + E1000_MRQC_RSS_FIELD_IPV6_TCP);
> > + mrqc |=( E1000_MRQC_RSS_FIELD_IPV4_UDP |
> > + E1000_MRQC_RSS_FIELD_IPV6_UDP);
> > + mrqc |=( E1000_MRQC_RSS_FIELD_IPV6_UDP_EX |
> > + E1000_MRQC_RSS_FIELD_IPV6_TCP_EX);
> > +
> > + E1000_WRITE_REG(hw, E1000_MRQC, mrqc);
> > +}
> > +
> > /*********************************************************************
> > *
> > * Enable receive unit.
> > @@ -4538,39 +4735,9 @@ igb_initialize_receive_units(struct adap
> > */
> > rxcsum = E1000_READ_REG(hw, E1000_RXCSUM);
> > if (adapter->num_queues >1) {
> > - u32 random[10], mrqc, shift = 0;
> > - union igb_reta {
> > - u32 dword;
> > - u8 bytes[4];
> > - } reta;
> > -
> > - arc4rand(&random, sizeof(random), 0);
> > - if (adapter->hw.mac.type == e1000_82575)
> > - shift = 6;
> > - /* Warning FM follows */
> > - for (int i = 0; i < 128; i++) {
> > - reta.bytes[i & 3] =
> > - (i % adapter->num_queues) << shift;
> > - if ((i & 3) == 3)
> > - E1000_WRITE_REG(hw,
> > - E1000_RETA(i >> 2), reta.dword);
> > - }
> > - /* Now fill in hash table */
> > - mrqc = E1000_MRQC_ENABLE_RSS_4Q;
> > - for (int i = 0; i < 10; i++)
> > - E1000_WRITE_REG_ARRAY(hw,
> > - E1000_RSSRK(0), i, random[i]);
> > -
> > - mrqc |= (E1000_MRQC_RSS_FIELD_IPV4 |
> > - E1000_MRQC_RSS_FIELD_IPV4_TCP);
> > - mrqc |= (E1000_MRQC_RSS_FIELD_IPV6 |
> > - E1000_MRQC_RSS_FIELD_IPV6_TCP);
> > - mrqc |=( E1000_MRQC_RSS_FIELD_IPV4_UDP |
> > - E1000_MRQC_RSS_FIELD_IPV6_UDP);
> > - mrqc |=( E1000_MRQC_RSS_FIELD_IPV6_UDP_EX |
> > - E1000_MRQC_RSS_FIELD_IPV6_TCP_EX);
> >
> > - E1000_WRITE_REG(hw, E1000_MRQC, mrqc);
> > + /* rss setup */
> > + igb_initialise_rss_mapping(adapter);
> >
> > /*
> > ** NOTE: Receive Full-Packet Checksum Offload
> > @@ -4831,7 +4998,7 @@ igb_rxeof(struct igb_queue *que, int cou
> > for (i = rxr->next_to_check; count != 0;) {
> > struct mbuf *sendmp, *mh, *mp;
> > struct igb_rx_buf *rxbuf;
> > - u16 hlen, plen, hdr, vtag;
> > + u16 hlen, plen, hdr, vtag, pkt_info;
> > bool eop = FALSE;
> >
> > cur = &rxr->rx_base[i];
> > @@ -4853,6 +5020,7 @@ igb_rxeof(struct igb_queue *que, int cou
> > else
> > vtag = le16toh(cur->wb.upper.vlan);
> > hdr = le16toh(cur->wb.lower.lo_dword.hs_rss.hdr_info);
> > + pkt_info =
> le16toh(cur->wb.lower.lo_dword.hs_rss.pkt_info);
> > eop = ((staterr & E1000_RXD_STAT_EOP) ==
> E1000_RXD_STAT_EOP);
> >
> > /* Make sure all segments of a bad packet are discarded
> */
> > @@ -4952,7 +5120,43 @@ igb_rxeof(struct igb_queue *que, int cou
> > rxr->fmp->m_pkthdr.ether_vtag = vtag;
> > rxr->fmp->m_flags |= M_VLANTAG;
> > }
> > -#ifndef IGB_LEGACY_TX
> > +#ifdef RSS
> > + /* XXX set flowtype once this works right */
> > + rxr->fmp->m_pkthdr.flowid =
> > + le32toh(cur->wb.lower.hi_dword.rss);
> > + rxr->fmp->m_flags |= M_FLOWID;
> > + switch (pkt_info & E1000_RXDADV_RSSTYPE_MASK) {
> > + case E1000_RXDADV_RSSTYPE_IPV4_TCP:
> > + M_HASHTYPE_SET(rxr->fmp,
> M_HASHTYPE_RSS_TCP_IPV4);
> > + break;
> > + case E1000_RXDADV_RSSTYPE_IPV4:
> > + M_HASHTYPE_SET(rxr->fmp,
> M_HASHTYPE_RSS_IPV4);
> > + break;
> > + case E1000_RXDADV_RSSTYPE_IPV6_TCP:
> > + M_HASHTYPE_SET(rxr->fmp,
> M_HASHTYPE_RSS_TCP_IPV6);
> > + break;
> > + case E1000_RXDADV_RSSTYPE_IPV6_EX:
> > + M_HASHTYPE_SET(rxr->fmp,
> M_HASHTYPE_RSS_IPV6_EX);
> > + break;
> > + case E1000_RXDADV_RSSTYPE_IPV6:
> > + M_HASHTYPE_SET(rxr->fmp,
> M_HASHTYPE_RSS_IPV6);
> > + break;
> > + case E1000_RXDADV_RSSTYPE_IPV6_TCP_EX:
> > + M_HASHTYPE_SET(rxr->fmp,
> M_HASHTYPE_RSS_TCP_IPV6_EX);
> > + break;
> > +
> > + /* XXX no UDP support in RSS just yet */
> > +#ifdef notyet
> > + case E1000_RXDADV_RSSTYPE_IPV4_UDP:
> > + case E1000_RXDADV_RSSTYPE_IPV6_UDP:
> > + case E1000_RXDADV_RSSTYPE_IPV6_UDP_EX:
> > +#endif
> > +
> > + default:
> > + /* XXX fallthrough */
> > + M_HASHTYPE_SET(rxr->fmp,
> M_HASHTYPE_NONE);
> > + }
> > +#elif !defined(IGB_LEGACY_TX)
> > rxr->fmp->m_pkthdr.flowid = que->msix;
> > rxr->fmp->m_flags |= M_FLOWID;
> > #endif
> >
>
>
--
-----------------------------------------+-------------------------------
Prof. Luigi RIZZO, rizzo@iet.unipi.it . Dip. di Ing. dell'Informazione
http://www.iet.unipi.it/~luigi/ . Universita` di Pisa
TEL +39-050-2211611 . via Diotisalvi 2
Mobile +39-338-6809875 . 56122 PISA (Italy)
-----------------------------------------+-------------------------------
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