From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexei Starovoitov Subject: [PATCH v3 net-next] pktgen: introduce 'rx' mode Date: Thu, 30 Apr 2015 22:12:10 -0700 Message-ID: <1430457130-16003-1-git-send-email-ast@plumgrid.com> Cc: Eric Dumazet , netdev@vger.kernel.org To: "David S. Miller" Return-path: Received: from mail-pa0-f46.google.com ([209.85.220.46]:36420 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750786AbbEAFMU (ORCPT ); Fri, 1 May 2015 01:12:20 -0400 Received: by pabsx10 with SMTP id sx10so81235518pab.3 for ; Thu, 30 Apr 2015 22:12:19 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: Introduce 'RX' mode for pktgen which generates the packets using familiar pktgen commands, but feeds them into netif_receive_skb() instead of ndo_start_xmit(). It is designed to test netif_receive_skb and ingress qdisc performace only. Make sure to understand how it works before using it for other rx benchmarking. Sample script 'pktgen.sh': \#!/bin/bash function pgset() { local result echo $1 > $PGDEV result=`cat $PGDEV | fgrep "Result: OK:"` if [ "$result" = "" ]; then cat $PGDEV | fgrep Result: fi } ETH=$1 PGDEV=/proc/net/pktgen/kpktgend_0 pgset "rem_device_all" pgset "add_device $ETH" PGDEV=/proc/net/pktgen/$ETH pgset "rx" pgset "pkt_size 60" pgset "dst 99.1.1.2" pgset "dst_mac 90:e2:ba:6e:a8:e5" pgset "count 10000000" pgset "burst 32" PGDEV=/proc/net/pktgen/pgctrl echo "Running... ctrl^C to stop" pgset "start" echo "Done" cat /proc/net/pktgen/$ETH Usage: $ sudo ./pktgen.sh eth2 ... Result: OK: 232376(c232372+d3) usec, 10000000 (60byte,0frags) 43033682pps 20656Mb/sec (20656167360bps) errors: 10000000 Raw netif_receive_skb speed should be ~43 million packet per second on 3.7Ghz x86 and 'perf report' should look like: 37.69% kpktgend_0 [kernel.vmlinux] [k] __netif_receive_skb_core 25.81% kpktgend_0 [kernel.vmlinux] [k] kfree_skb 7.22% kpktgend_0 [kernel.vmlinux] [k] ip_rcv 5.68% kpktgend_0 [pktgen] [k] pktgen_thread_worker if fib_table_lookup is seen on top, it means skb was processed by the stack. To benchmark netif_receive_skb only make sure that 'dst_mac' of your pktgen script is different from receiving device mac and it will be dropped by ip_rcv Signed-off-by: Alexei Starovoitov --- v2->v3: addressed more Eric comments. Thanks! v1->v2: as suggested by Eric: - dropped 'clone_skb' flag, now it will return enotsupp - fix rps/rfs bug by checking skb->users after every netif_receive_skb - tested with RPS/RFS, taps, veth, physical devs, various tc cls/act net/core/pktgen.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 47 insertions(+), 2 deletions(-) diff --git a/net/core/pktgen.c b/net/core/pktgen.c index 508155b283dd..34fd5ece2681 100644 --- a/net/core/pktgen.c +++ b/net/core/pktgen.c @@ -203,6 +203,7 @@ #define F_NODE (1<<15) /* Node memory alloc*/ #define F_UDPCSUM (1<<16) /* Include UDP checksum */ #define F_NO_TIMESTAMP (1<<17) /* Don't timestamp packets (default TS) */ +#define F_DO_RX (1<<18) /* generate packets for RX */ /* Thread control flag bits */ #define T_STOP (1<<0) /* Stop run */ @@ -1081,7 +1082,8 @@ static ssize_t pktgen_if_write(struct file *file, if (len < 0) return len; if ((value > 0) && - (!(pkt_dev->odev->priv_flags & IFF_TX_SKB_SHARING))) + ((pkt_dev->flags & F_DO_RX) || + !(pkt_dev->odev->priv_flags & IFF_TX_SKB_SHARING))) return -ENOTSUPP; i += len; pkt_dev->clone_skb = value; @@ -1089,6 +1091,12 @@ static ssize_t pktgen_if_write(struct file *file, sprintf(pg_result, "OK: clone_skb=%d", pkt_dev->clone_skb); return count; } + if (!strcmp(name, "rx")) { + pkt_dev->flags |= F_DO_RX; + + sprintf(pg_result, "OK: RX is ON"); + return count; + } if (!strcmp(name, "count")) { len = num_arg(&user_buffer[i], 10, &value); if (len < 0) @@ -1134,7 +1142,7 @@ static ssize_t pktgen_if_write(struct file *file, return len; i += len; - if ((value > 1) && + if ((value > 1) && !(pkt_dev->flags & F_DO_RX) && (!(pkt_dev->odev->priv_flags & IFF_TX_SKB_SHARING))) return -ENOTSUPP; pkt_dev->burst = value < 1 ? 1 : value; @@ -3317,6 +3325,7 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev) unsigned int burst = ACCESS_ONCE(pkt_dev->burst); struct net_device *odev = pkt_dev->odev; struct netdev_queue *txq; + struct sk_buff *skb; int ret; /* If device is offline, then don't send */ @@ -3349,11 +3358,46 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev) pkt_dev->last_pkt_size = pkt_dev->skb->len; pkt_dev->allocated_skbs++; pkt_dev->clone_count = 0; /* reset counter */ + if (pkt_dev->flags & F_DO_RX) + pkt_dev->skb->protocol = eth_type_trans(pkt_dev->skb, + pkt_dev->skb->dev); } if (pkt_dev->delay && pkt_dev->last_ok) spin(pkt_dev, pkt_dev->next_tx); + if (pkt_dev->flags & F_DO_RX) { + skb = pkt_dev->skb; + atomic_add(burst, &skb->users); + local_bh_disable(); + do { + ret = netif_receive_skb(skb); + if (ret == NET_RX_DROP) + pkt_dev->errors++; + pkt_dev->sofar++; + pkt_dev->seq_num++; + if (atomic_read(&skb->users) != burst) { + /* skb was queued by rps/rfs or taps, + * so cannot reuse this skb + */ + atomic_sub(burst - 1, &skb->users); + /* get out of the loop and wait + * until skb is consumed + */ + pkt_dev->last_ok = 1; + pkt_dev->clone_skb = 0; + break; + } + /* skb was 'freed' by stack, so clean few + * bits and reuse it + */ +#ifdef CONFIG_NET_CLS_ACT + skb->tc_verd = 0; /* reset reclass/redir ttl */ +#endif + } while (--burst > 0); + goto out; + } + txq = skb_get_tx_queue(odev, pkt_dev->skb); local_bh_disable(); @@ -3401,6 +3445,7 @@ xmit_more: unlock: HARD_TX_UNLOCK(odev, txq); +out: local_bh_enable(); /* If pkt_dev->count is zero, then run forever */ -- 1.7.9.5