linux/tools
Florian Westphal d6a367ec6c netfilter: nft_flowtable.sh: re-run with random mtu sizes
Jakub says:
 nft_flowtable.sh is one of the most flake-atious test for netdev CI currently :(

The root cause is two-fold:
1. the failing part of the test is supposed to make sure that ip
   fragments are forwarded for offloaded flows.
   (flowtable has to pass them to classic forward path).
   path mtu discovery for these subtests is disabled.

2. nft_flowtable.sh has two passes.  One with fixed mtus/file size and
  one where link mtus and file sizes are random.

The CI failures all have same pattern:
  re-run with random mtus and file size: -o 27663 -l 4117 -r 10089 -s 54384840
  [..]
  PASS: dscp_egress: dscp packet counters match
  FAIL: file mismatch for ns1 -> ns2

In some cases this error triggers a bit ealier, sometimes in a later
subtest:
  re-run with random mtus and file size: -o 20201 -l 4555 -r 12657 -s 9405856
  [..]
  PASS: dscp_egress: dscp packet counters match
  PASS: dscp_fwd: dscp packet counters match
  2025/08/17 20:37:52 socat[18954] E write(7, 0x560716b96000, 8192): Broken pipe
  FAIL: file mismatch for ns1 -> ns2
  -rw------- 1 root root 9405856 Aug 17 20:36 /tmp/tmp.2n63vlTrQe

But all logs I saw show same scenario:
1. Failing tests have pmtu discovery off (i.e., ip fragmentation)
2. The test file is much larger than first-pass default (2M Byte)
3. peers have much larger MTUs compared to the 'network'.

These errors are very reproducible when re-running the test with
the same commandline arguments.

The timeout became much more prominent with
1d2fbaad7c ("tcp: stronger sk_rcvbuf checks"): reassembled packets
typically have a skb->truesize more than double the skb length.

As that commit is intentional and pmtud-off with
large-tcp-packets-as-fragments is not normal adjust the test to use a
smaller file for the pmtu-off subtests.

While at it, add more information to pass/fail messages and
also run the dscp alteration subtest with pmtu discovery enabled.

Link: https://netdev.bots.linux.dev/contest.html?test=nft-flowtable-sh
Fixes: f84ab63490 ("selftests: netfilter: nft_flowtable.sh: re-run with random mtu sizes")
Reported-by: Jakub Kicinski <kuba@kernel.org>
Closes: https://lore.kernel.org/netdev/20250822071330.4168f0db@kernel.org/
Signed-off-by: Florian Westphal <fw@strlen.de>
Link: https://patch.msgid.link/20250828214918.3385-1-fw@strlen.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-29 18:53:53 -07:00
..
accounting tools/getdelays: add backward compatibility for taskstats version 2025-08-02 12:01:41 -07:00
arch tools headers: Sync powerpc headers with the kernel source 2025-08-18 13:49:25 -07:00
bootconfig bootconfig: Fix negative seeks on 32-bit with LFS enabled 2025-08-21 08:16:31 +09:00
bpf bpftool: Add support for dumping streams 2025-07-03 19:30:07 -07:00
build tools: Remove libcrypto dependency 2025-06-26 10:51:41 -07:00
certs
cgroup memcg_slabinfo: Fix use of PG_slab 2025-07-23 11:55:22 +02:00
counter
crypto
debugging
firewire
firmware
gpio
hv tools/hv: fcopy: Fix irregularities with size of ring buffer 2025-07-15 06:25:33 +00:00
iio
include perf-tools fixes for v6.17-rc4 2025-08-27 19:18:51 -07:00
kvm/kvm_stat
laptop
leds
lib libbpf: Add the ability to suppress perf event enablement 2025-08-07 09:01:41 -07:00
memory-model
mm tools/mm: add script to display page state for a given PID and VADDR 2025-07-09 22:41:53 -07:00
net tools: ynl-gen: print setters for multi-val attrs 2025-07-24 17:28:49 -07:00
objtool objtool/LoongArch: Get table size correctly if LTO is enabled 2025-08-20 22:23:15 +08:00
pcmcia
perf perf symbol: Add blocking argument to filename__read_build_id 2025-08-25 15:07:18 -07:00
power cpupower: Allow control of boost feature on non-x86 based systems with boost support. 2025-08-15 10:49:14 -06:00
rcu
sched tools/sched: Add dl_bw_dump.py for printing bandwidth accounting info 2025-07-14 10:59:33 +02:00
sched_ext sched_ext: Add support for cgroup bandwidth control interface 2025-06-20 17:03:51 -10:00
scripts tools headers: Sync syscall tables with the kernel source 2025-08-18 13:49:25 -07:00
sound
spi
testing netfilter: nft_flowtable.sh: re-run with random mtu sizes 2025-08-29 18:53:53 -07:00
thermal
time
tracing rtla: Check pkg-config install 2025-08-19 20:32:54 -04:00
usb
verification rv: Add opid per-cpu monitor 2025-07-28 16:47:35 -04:00
virtio
wmi
workqueue
writeback
Makefile