Going to update with v4, I see some netdev failures on non-appeared trace events. I need to review the synchronization on the tracer thread. pw-bot: changes-requested On Thu, 15 Aug 2024 at 22:32, Dmitry Safonov via B4 Relay <devnull+0x7f454c46.gmail.com@xxxxxxxxxx> wrote: > > First 3 patches are more-or-less cleanups/preparations. > > Patches 4/5 are fixes for netns file descriptors leaks/open. > > Patch 6 was sent to me/contributed off-list by Mohammad, who wants 32-bit > kernels to run TCP-AO. > > Patch 7 is a workaround/fix for slow VMs. Albeit, I can't reproduce > the issue, but I hope it will fix netdev flakes for connect-deny-* > tests. > > And the biggest change is adding TCP-AO tracepoints to selftests. > I think it's a good addition by the following reasons: > - The related tracepoints are now tested; > - It allows tcp-ao selftests to raise expectations on the kernel > behavior - up from the syscalls exit statuses + net counters. > - Provides tracepoints usage samples. > > As tracepoints are not a stable ABI, any kernel changes done to them > will be reflected to the selftests, which also will allow users > to see how to change their code. It's quite better than parsing dmesg > (what BGP was doing pre-tracepoints, ugh). > > Somewhat arguably, the code parses trace_pipe, rather than uses > libtraceevent (which any sane user should do). The reason behind that is > the same as for rt-netlink macros instead of libmnl: I'm trying > to minimize the library dependencies of the selftests. And the > performance of formatting text in kernel and parsing it again in a test > is not critical. > > Current output sample: > > ok 73 Trace events matched expectations: 13 tcp_hash_md5_required[2] tcp_hash_md5_unexpected[4] tcp_hash_ao_required[3] tcp_ao_key_not_found[4] > > Previously, tracepoints selftests were part of kernel tcp tracepoints > submission [1], but since then the code was quite changed: > - Now generic tracing setup is in lib/ftrace.c, separate from > lib/ftrace-tcp.c which utilizes TCP trace points. This separation > allows future selftests to trace non-TCP events, i.e. to find out > an skb's drop reason, which was useful in the creation of TCP-CLOSE > stress-test (not in this patch set, but used in attempt to reproduce > the issue from [2]). > - Another change is that in the previous submission the trace events > where used only to detect unexpected TCP-AO/TCP-MD5 events. In this > version the selftests will fail if an expected trace event didn't > appear. > Let's see how reliable this is on the netdev bot - it obviously passes > on my testing, but potentially may require a temporary XFAIL patch > if it misbehaves on a slow VM. > > [1] https://lore.kernel.org/lkml/20240224-tcp-ao-tracepoints-v1-0-15f31b7f30a7@xxxxxxxxxx/ > [2] https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=33700a0c9b56 > > Signed-off-by: Dmitry Safonov <0x7f454c46@xxxxxxxxx> [..] Sorry for the noise, Dmitry
