From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yang Hongyang Subject: Re: [PATCH 0/5] tracing/events: add tracepoint to TCP/IP stack and netdev layer Date: Wed, 20 Jan 2010 09:41:11 +0800 Message-ID: <4B565F37.3070809@cn.fujitsu.com> References: <4B541B31.5090207@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, davem@davemloft.net, nhorman@tuxdriver.com, izumi.taku@jp.fujitsu.com, kaneshige.kenji@jp.fujitsu.com To: Koki Sanagi Return-path: Received: from cn.fujitsu.com ([222.73.24.84]:53075 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1755399Ab0ATBkY (ORCPT ); Tue, 19 Jan 2010 20:40:24 -0500 In-Reply-To: <4B541B31.5090207@jp.fujitsu.com> Sender: netdev-owner@vger.kernel.org List-ID: Koki Sanagi wrote: > These patch-set adds some tracepoints to the TCP/IP stack and netdev layer. > > As described below, > http://marc.info/?l=linux-netdev&m=126096487212459&w=2 > dev_hard_start_xmit and netif_receive_skb are important location to add > tracepoints. Because driver depends on an machine environment, we usually > check this point when solving network problem. But these two points are lack of > infrotmation that what packets are passed, So I add other tracepoints to know > what packets are passed and to give some merits. > > Added tracepoints are at transmit/receive entry of TCP, UDP, RAW, IPv4, driver > and Qdisc. And tracepoints to output information to make connection > between these entry tracepoints are also added. > > These tracepoints give some merits. > For example, they enable us to measure packet latency. > By using tcpdump, we can analyze what packets are passed, but we cannot analyze > how long it takes to pass through network layer(In other words, latency of TCP > layer, IP layer and Qdisc). > Packet latency is very useful information to solve a network bad performance or > bad reaction network application, packet latency is very useful information. If you could point out what the actual problem these tracepoints can solve, It will be a lot more peruasive. And this patch-set contains a lot of tracepoints.Can you figure out what's the most important?Are these tracepoints really necessary.You could send out the most important tracepoints instead of sending out all these. > > As an other use case, unlike a tcpdump, they are recorded in ftrace buffer > without IO burden. Only when you need, output recorded information. > I mean, they are fit to run always. > > Details of added tracepoint are below. > > skb_clone chase the cloned skb > senddata_copy_skb copy userdata to skb for transmit > > netdev_start_xmit entry of driver's transmit function. > netdev_receive_skb entry of netstack(receive). > dev_queue_xmit entry of Qdisc. > > ip_queue_xmit entry of IP layer(TCP transmit) > ip_push_pending_frames entry of IP layer(UDP transmit) > ip_output entry of IP layer(RAW transmit) > ip_frag_queue aggregate fragmented packet > ip_frag_reasm reasemble fragmented packet > ip_rcv entry of IP layer(receive) > > tcp_sendmsg entry of TCP layer(transmit) > tcp_sendpage entry of TCP layer(transmit) > tcp_push_pending_frames all data(tcp_sendmsg have) have copied to skb > tcp_v4_rcv entry of TCP layer(receive) > > udp_sendmsg entry of UDP layer(transmit) > udp_sendpage entry of UDP layer(transmit) > udp_push_pending_frames all data(udp_sendmsg have) have copied to skb > udp_rcv entry of UDP layer(receive). > > raw_sendmsg entry of RAW layer(transmit). > raw_rcv entry of RAW layer(receive). > > Outputs are below. > > TCP send > netperf-2513 [000] 2603.586818: tcp_sendmsg: sk=f644eac0 len=5000 > netperf-2513 [000] 2603.586818: senddata_copy_skb: sk=f644eac0 skbaddr=f7159800 len=1416 > netperf-2513 [000] 2603.586820: senddata_copy_skb: sk=f644eac0 skbaddr=f7159500 len=1448 > netperf-2513 [000] 2603.586821: senddata_copy_skb: sk=f644eac0 skbaddr=f7158d80 len=1448 > netperf-2513 [000] 2603.586822: senddata_copy_skb: sk=f644eac0 skbaddr=f7159c80 len=688 > netperf-2513 [000] 2603.586822: tcp_push_pending_frames: sk=f644eac0 sport=54875 dport=51707 > tail-2514 [001] 2603.587577: skb_clone: original=f7159800 clone=f71598b4 > tail-2514 [001] 2603.587578: ip_queue_xmit: skbaddr=f71598b4 saddr=192.168.100.5 daddr=192.168.100.2 > tail-2514 [001] 2603.587579: ip_output: skbaddr=f71598b4 saddr=192.168.100.5 daddr=192.168.100.2 > tail-2514 [001] 2603.587579: dev_queue_xmit: dev=eth10 skbaddr=f71598b4 len=1514 > tail-2514 [001] 2603.587580: netdev_start_xmit: dev=eth10 skbaddr=f71598b4 len=1514 > tail-2514 [001] 2603.587628: skb_clone: original=f7159500 clone=f71595b4 > tail-2514 [001] 2603.587629: ip_queue_xmit: skbaddr=f71595b4 saddr=192.168.100.5 daddr=192.168.100.2 > tail-2514 [001] 2603.587630: ip_output: skbaddr=f71595b4 saddr=192.168.100.5 daddr=192.168.100.2 > tail-2514 [001] 2603.587631: dev_queue_xmit: dev=eth10 skbaddr=f71595b4 len=1514 > tail-2514 [001] 2603.587632: netdev_start_xmit: dev=eth10 skbaddr=f71595b4 len=1514 > tail-2514 [001] 2603.587632: skb_clone: original=f7158d80 clone=f7158e34 > tail-2514 [001] 2603.587633: ip_queue_xmit: skbaddr=f7158e34 saddr=192.168.100.5 daddr=192.168.100.2 > tail-2514 [001] 2603.587634: ip_output: skbaddr=f7158e34 saddr=192.168.100.5 daddr=192.168.100.2 > tail-2514 [001] 2603.587635: dev_queue_xmit: dev=eth10 skbaddr=f7158e34 len=1514 > tail-2514 [001] 2603.587635: netdev_start_xmit: dev=eth10 skbaddr=f7158e34 len=1514 > tail-2514 [001] 2603.587685: skb_clone: original=f7159c80 clone=f7159d34 > tail-2514 [001] 2603.587685: ip_queue_xmit: skbaddr=f7159d34 saddr=192.168.100.5 daddr=192.168.100.2 > tail-2514 [001] 2603.587687: ip_output: skbaddr=f7159d34 saddr=192.168.100.5 daddr=192.168.100.2 > tail-2514 [001] 2603.587687: dev_queue_xmit: dev=eth10 skbaddr=f7159d34 len=1514 > tail-2514 [001] 2603.587688: netdev_start_xmit: dev=eth10 skbaddr=f7159d34 len=1514 > > TCP recv > -0 [001] 3499.386601: netdev_receive_skb: dev=eth10 skbaddr=f4a88480 len=1500 > -0 [001] 3499.386602: ip_rcv: skbaddr=f4a88480 saddr=192.168.100.2 daddr=192.168.100.5 > -0 [001] 3499.386604: tcp_v4_rcv: skbaddr=f4a88480 sport=51035 dport=34474 > -0 [000] 3499.386619: netdev_receive_skb: dev=eth10 skbaddr=f3c75300 len=1500 > -0 [000] 3499.386619: ip_rcv: skbaddr=f3c75300 saddr=192.168.100.2 daddr=192.168.100.5 > -0 [000] 3499.386622: tcp_v4_rcv: skbaddr=f3c75300 sport=51035 dport=34474 > netserver-2519 [000] 3499.386626: skb_copy_datagram_iovec: skbaddr=f4a88480 len=1448 > netserver-2519 [000] 3499.386628: skb_copy_datagram_iovec: skbaddr=f3c75300 len=1448 > > UDP send > netperf-2506 [001] 2309.073460: udp_sendmsg: sk=f662e6c0 len=5000 > netperf-2506 [001] 2309.073466: senddata_copy_skb: sk=f662e6c0 skbaddr=f5f65780 len=1472 > netperf-2506 [001] 2309.073467: senddata_copy_skb: sk=f662e6c0 skbaddr=f5f65000 len=1480 > netperf-2506 [001] 2309.073468: senddata_copy_skb: sk=f662e6c0 skbaddr=f3decf00 len=1480 > netperf-2506 [001] 2309.073469: senddata_copy_skb: sk=f662e6c0 skbaddr=f4802840 len=568 > netperf-2506 [001] 2309.073470: udp_push_pending_frames: sk=f662e6c0 sport=42679 dport=47640 > netperf-2506 [001] 2309.073470: ip_push_pending_frames: skbaddr=f5f65780 saddr=192.168.100.5 daddr=192.168.100.2 > netperf-2506 [001] 2309.073471: ip_output: skbaddr=f5f65780 saddr=192.168.100.5 daddr=192.168.100.2 > netperf-2506 [001] 2309.073472: dev_queue_xmit: dev=eth10 skbaddr=f5f65780 len=1514 > netperf-2506 [001] 2309.073473: dev_queue_xmit: dev=eth10 skbaddr=f5f65000 len=1514 > netperf-2506 [001] 2309.073474: dev_queue_xmit: dev=eth10 skbaddr=f3decf00 len=1514 > netperf-2506 [001] 2309.073474: dev_queue_xmit: dev=eth10 skbaddr=f4802840 len=602 > -0 [001] 2309.073615: netdev_start_xmit: dev=eth10 skbaddr=f5f65780 len=1514 > -0 [001] 2309.073616: netdev_start_xmit: dev=eth10 skbaddr=f5f65000 len=1514 > -0 [000] 2309.073633: netdev_start_xmit: dev=eth10 skbaddr=f3decf00 len=1514 > -0 [000] 2309.073633: netdev_start_xmit: dev=eth10 skbaddr=f4802840 len=602 > > UDP recv > -0 [001] 3671.663678: netdev_receive_skb: dev=eth10 skbaddr=f5f72d80 len=1500 > -0 [001] 3671.663678: ip_rcv: skbaddr=f5f72d80 saddr=192.168.100.2 daddr=192.168.100.5 > -0 [001] 3671.663680: ip_frag_queue: skbaddr=f5f72d80 prev=(null) > -0 [001] 3671.663681: netdev_receive_skb: dev=eth10 skbaddr=f5f6aa80 len=1500 > -0 [001] 3671.663681: ip_rcv: skbaddr=f5f6aa80 saddr=192.168.100.2 daddr=192.168.100.5 > -0 [001] 3671.663681: ip_frag_queue: skbaddr=f5f6aa80 prev=f5f72d80 > -0 [000] 3671.663702: netdev_receive_skb: dev=eth10 skbaddr=f4800840 len=1500 > -0 [000] 3671.663703: ip_rcv: skbaddr=f4800840 saddr=192.168.100.2 daddr=192.168.100.5 > -0 [000] 3671.663703: ip_frag_queue: skbaddr=f4800840 prev=f5f6aa80 > -0 [000] 3671.663704: netdev_receive_skb: dev=eth10 skbaddr=f4a88b40 len=588 > -0 [000] 3671.663705: ip_rcv: skbaddr=f4a88b40 saddr=192.168.100.2 daddr=192.168.100.5 > -0 [000] 3671.663705: ip_frag_queue: skbaddr=f4a88b40 prev=f4800840 > -0 [000] 3671.663706: skb_clone: original=f4a88b40 clone=f5fff480 > -0 [000] 3671.663707: kfree_skb: skbaddr=f5f72d80 protocol=2048 location=c0715f1a > -0 [000] 3671.663707: ip_frag_reasm: head=f4a88b40 len=1480 > -0 [000] 3671.663711: udp_rcv: skbaddr=f4a88b40 sport=57915 dport=37634 > netserver-2525 [000] 3671.663718: skb_copy_datagram_iovec: skbaddr=f4a88b40 len=5000 > netserver-2525 [000] 3671.663718: skb_copy_datagram_iovec: skbaddr=f5f6aa80 len=1480 > netserver-2525 [000] 3671.663719: skb_copy_datagram_iovec: skbaddr=f4800840 len=1480 > netserver-2525 [000] 3671.663719: skb_copy_datagram_iovec: skbaddr=f5fff480 len=568 > > RAW send > send-2431 [001] 1813.799957: raw_sendmsg: sk=f4a37200 len=1500 > send-2431 [001] 1813.799959: senddata_copy_skb: sk=f4a37200 skbaddr=f3dec180 len=1500 > send-2431 [001] 1813.799960: ip_output: skbaddr=f3dec180 saddr=192.168.100.5 daddr=192.168.100.2 > send-2431 [001] 1813.799960: dev_queue_xmit: dev=eth10 skbaddr=f3dec180 len=1514 > send-2431 [001] 1813.799961: netdev_start_xmit: dev=eth10 skbaddr=f3dec180 len=1514 > > RAW recv > -0 [000] 2052.858947: netdev_receive_skb: dev=eth1 skbaddr=f5f66000 len=1500 > -0 [000] 2052.858947: ip_rcv: skbaddr=f5f66000 saddr=192.168.101.2 daddr=192.168.101.5 > -0 [000] 2052.858951: skb_clone: original=f5f66000 clone=f3e43cc0 > -0 [000] 2052.858952: raw_rcv: skbaddr=f3e43cc0 len=1476 > recv-2499 [001] 2052.858970: skb_copy_datagram_iovec: skbaddr=f3e43cc0 len=1500 > > Best Regards, > Koki Sanagi > > -- > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- Regards Yang Hongyang