kernel/linux.git/tools/testing/selftests/net/msg_zerocopy.c, branch v6.19.11

selftest: net: extend msg_zerocopy test with forwarding

2025-07-02T22:07:16+00:00

Zerocopy skbs are converted to regular copy skbs when data is queued to a local socket. This happens in the existing test with a sender and receiver communicating over a veth device. Zerocopy skbs are sent without copying if egressing a device. Verify that this behavior is maintained even in the common container setup where data is forwarded over a veth to the physical device. Update msg_zerocopy.sh to 1. Have a dummy network device to simulate a physical device. 2. Have forwarding enabled between veth and dummy. 3. Add a tx-only test that sends out dummy via the forwarding path. 4. Verify the exitcode of the sender, which signals zerocopy success. As dummy drops all packets, this cannot be a TCP connection. Test the new case with unconnected UDP only. Update msg_zerocopy.c to - Accept an argument whether send with zerocopy is expected. - Return an exitcode whether behavior matched that expectation. Signed-off-by: Willem de Bruijn Link: https://patch.msgid.link/20250630194312.1571410-3-willemdebruijn.kernel@gmail.com Signed-off-by: Jakub Kicinski

selftests: make order checking verbose in msg_zerocopy selftest

2024-07-04T02:42:32+00:00

We find that when lock debugging is on, notifications may not come in order. Thus, we have order checking outputs managed by cfg_verbose, to avoid too many outputs in this case. Fixes: 07b65c5b31ce ("test: add msg_zerocopy test") Signed-off-by: Zijian Zhang Signed-off-by: Xiaochun Lu Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20240701225349.3395580-3-zijianzhang@bytedance.com Signed-off-by: Jakub Kicinski

selftests: fix OOM in msg_zerocopy selftest

2024-07-04T02:42:32+00:00

In selftests/net/msg_zerocopy.c, it has a while loop keeps calling sendmsg on a socket with MSG_ZEROCOPY flag, and it will recv the notifications until the socket is not writable. Typically, it will start the receiving process after around 30+ sendmsgs. However, as the introduction of commit dfa2f0483360 ("tcp: get rid of sysctl_tcp_adv_win_scale"), the sender is always writable and does not get any chance to run recv notifications. The selftest always exits with OUT_OF_MEMORY because the memory used by opt_skb exceeds the net.core.optmem_max. Meanwhile, it could be set to a different value to trigger OOM on older kernels too. Thus, we introduce "cfg_notification_limit" to force sender to receive notifications after some number of sendmsgs. Fixes: 07b65c5b31ce ("test: add msg_zerocopy test") Signed-off-by: Zijian Zhang Signed-off-by: Xiaochun Lu Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20240701225349.3395580-2-zijianzhang@bytedance.com Signed-off-by: Jakub Kicinski

selftests/net: relax cpu affinity requirement in msg_zerocopy test

2020-08-05T19:25:35+00:00

The msg_zerocopy test pins the sender and receiver threads to separate cores to reduce variance between runs. But it hardcodes the cores and skips core 0, so it fails on machines with the selected cores offline, or simply fewer cores. The test mainly gives code coverage in automated runs. The throughput of zerocopy ('-z') and non-zerocopy runs is logged for manual inspection. Continue even when sched_setaffinity fails. Just log to warn anyone interpreting the data. Fixes: 07b65c5b31ce ("test: add msg_zerocopy test") Reported-by: Colin Ian King Signed-off-by: Willem de Bruijn Acked-by: Colin Ian King Signed-off-by: David S. Miller

selftests: extend zerocopy tests to udp

2018-12-03T23:58:32+00:00

Both msg_zerocopy and udpgso_bench have udp zerocopy variants. Exercise these as part of the standard kselftest run. With udp, msg_zerocopy has no control channel. Ensure that the receiver exits after the sender by accounting for the initial delay in starting them (in msg_zerocopy.sh). Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller

selftests/net: reap zerocopy completions passed up as ancillary data.

2018-02-27T19:19:11+00:00

PF_RDS sockets pass up cookies for zerocopy completion as ancillary data. Update msg_zerocopy to reap this information. Signed-off-by: Sowmini Varadhan Acked-by: Willem de Bruijn Acked-by: Santosh Shilimkar Signed-off-by: David S. Miller

selftests/net: revert the zerocopy Rx path for PF_RDS

2018-02-27T19:19:10+00:00

In preparation for optimized reception of zerocopy completion, revert the Rx side changes introduced by Commit dfb8434b0a94 ("selftests/net: add zerocopy support for PF_RDS test case") Signed-off-by: Sowmini Varadhan Acked-by: Willem de Bruijn Acked-by: Santosh Shilimkar Signed-off-by: David S. Miller

selftests/net: add zerocopy support for PF_RDS test case

2018-02-16T21:04:17+00:00

Send a cookie with sendmsg() on PF_RDS sockets, and process the returned batched cookies in do_recv_completion() Signed-off-by: Sowmini Varadhan Acked-by: Willem de Bruijn Signed-off-by: David S. Miller

selftests/net: add support for PF_RDS sockets

2018-02-16T21:04:17+00:00

Add support for basic PF_RDS client-server testing in msg_zerocopy Signed-off-by: Sowmini Varadhan Acked-by: Willem de Bruijn Signed-off-by: David S. Miller

selftests/net: fix bugs in address and port initialization

2018-01-02T18:26:58+00:00

Address/port initialization should work correctly regardless of the order in which command line arguments are supplied, E.g, cfg_port should be used to connect to the remote host even if it is processed after -D, src/dst address initialization should not require that [-4|-6] be specified before the -S or -D args, receiver should be able to bind to *. Achieve this by making sure that the address/port structures are initialized after all command line options are parsed. Store cfg_port in host-byte order, and use htons() to set up the sin_port/sin6_port before bind/connect, so that the network system calls get the correct values in network-byte order. Signed-off-by: Sowmini Varadhan Acked-by: Willem de Bruijn Signed-off-by: David S. Miller