linux-dev/include/trace/events/tcp.h, branch linus/master

tcp: Add tracepoint for tcp_set_ca_state

2022-04-08T03:33:15Z

The congestion status of a tcp flow may be updated since there is congestion between tcp sender and receiver. It makes sense to add tracepoint for congestion status set function to summate cc status duration and evaluate the performance of network and congestion algorithm. the backgound of this patch is below. Link: https://github.com/iovisor/bcc/pull/3899 Signed-off-by: Ping Gan Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20220406010956.19656-1-jacky_gam_2001@163.com Signed-off-by: Jakub Kicinski

tcp: add accessors to read/set tp->snd_cwnd

2022-04-06T19:05:41Z

We had various bugs over the years with code breaking the assumption that tp->snd_cwnd is greater than zero. Lately, syzbot reported the WARN_ON_ONCE(!tp->prior_cwnd) added in commit 8b8a321ff72c ("tcp: fix zero cwnd in tcp_cwnd_reduction") can trigger, and without a repro we would have to spend considerable time finding the bug. Instead of complaining too late, we want to catch where and when tp->snd_cwnd is set to an illegal value. Signed-off-by: Eric Dumazet Suggested-by: Yuchung Cheng Cc: Neal Cardwell Acked-by: Yuchung Cheng Link: https://lore.kernel.org/r/20220405233538.947344-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski

tcp: add tracepoint for checksum errors

2021-05-14T22:26:03Z

Add a tracepoint for capturing TCP segments with a bad checksum. This makes it easy to identify sources of bad frames in the fleet (e.g. machines with faulty NICs). It should also help tools like IOvisor's tcpdrop.py which are used today to get detailed information about such packets. We don't have a socket in many cases so we must open code the address extraction based just on the skb. v2: add missing export for ipv6=m Signed-off-by: Jakub Kicinski Signed-off-by: David S. Miller

net: tracepoint: exposing sk_family in all tcp:tracepoints

2021-02-04T17:25:36Z

Similar to sock:inet_sock_set_state tracepoint, expose sk_family to distinguish AF_INET and AF_INET6 families. The following tcp tracepoints are updated: tcp:tcp_destroy_sock tcp:tcp_rcv_space_adjust tcp:tcp_retransmit_skb tcp:tcp_send_reset tcp:tcp_receive_reset tcp:tcp_retransmit_synack tcp:tcp_probe Signed-off-by: Hariharan Ananthakrishnan Signed-off-by: Brendan Gregg Link: https://lore.kernel.org/r/20210129001210.344438-1-hari@netflix.com Signed-off-by: Jakub Kicinski

tcp: remove redundant new line from tcp_event_sk_skb

2019-11-10T03:41:50Z

This removes '\n' from trace event class tcp_event_sk_skb to avoid redundant new blank line and make output compact. Fixes: af4325ecc24f ("tcp: expose sk_state in tcp_retransmit_skb tracepoint") Reviewed-by: Eric Dumazet Reviewed-by: Yafang Shao Signed-off-by: Tony Lu Signed-off-by: David S. Miller

tcp: expose sk_state in tcp_retransmit_skb tracepoint

2018-09-27T03:07:19Z

After sk_state exposed, we can get in which state this retransmission occurs. That could give us more detail for dignostic. For example, if this retransmission occurs in SYN_SENT state, it may also indicates that the syn packet may be dropped on the remote peer due to syn backlog queue full and then we could check the remote peer. BTW,SYNACK retransmission is traced in tcp_retransmit_synack tracepoint. Signed-off-by: Yafang Shao Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

tcp: minor optimization around tcp_hdr() usage in receive path

2018-05-31T17:20:47Z

This is additional to the commit ea1627c20c34 ("tcp: minor optimizations around tcp_hdr() usage"). At this point, skb->data is same with tcp_hdr() as tcp header has not been pulled yet. So use the less expensive one to get the tcp header. Remove the third parameter of tcp_rcv_established() and put it into the function body. Furthermore, the local variables are listed as a reverse christmas tree :) Cc: Eric Dumazet Signed-off-by: Yafang Shao Signed-off-by: David S. Miller

tcp: use data length instead of skb->len in tcp_probe

2018-05-29T14:15:37Z

skb->len is meaningless to user. data length could be more helpful, with which we can easily filter out the packet without payload. Signed-off-by: Yafang Shao Acked-by: Song Liu Signed-off-by: David S. Miller

net: introduce a new tracepoint for tcp_rcv_space_adjust

2018-04-23T13:58:18Z

tcp_rcv_space_adjust is called every time data is copied to user space, introducing a tcp tracepoint for which could show us when the packet is copied to user. When a tcp packet arrives, tcp_rcv_established() will be called and with the existed tracepoint tcp_probe we could get the time when this packet arrives. Then this packet will be copied to user, and tcp_rcv_space_adjust will be called and with this new introduced tracepoint we could get the time when this packet is copied to user. With these two tracepoints, we could figure out whether the user program processes this packet immediately or there's latency. Hence in the printk message, sk_cookie is printed as a key to relate tcp_rcv_space_adjust with tcp_probe. Maybe we could export sockfd in this new tracepoint as well, then we could relate this new tracepoint with epoll/read/recv* tracepoints, and finally that could show us the whole lifespan of this packet. But we could also implement that with pid as these functions are executed in process context. Signed-off-by: Yafang Shao Signed-off-by: David S. Miller

net: Remove unused tcp_set_state tracepoint

2018-04-16T23:02:15Z

This tracepoint was replaced by inet_sock_set_state in 563e0bb and not used anywhere in the kernel anymore. Remove it. Signed-off-by: Andrey Ignatov Signed-off-by: David S. Miller