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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
arch powerpc fixes for 6.17 #3 2025-08-28 15:39:06 -07:00
block block: avoid cpu_hotplug_lock depedency on freeze_lock 2025-08-21 07:11:11 -06:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto Significant patch series in this pull request: 2025-08-03 16:23:09 -07:00
Documentation Devicetree fixes for v6.17, part 1: 2025-08-25 18:47:58 -07:00
drivers Some fixes for the current cycle: 2025-08-29 13:35:13 -07:00
fs Driver core fixes for 6.16-rc3 2025-08-23 09:04:32 -04:00
include Including fixes from Bluetooth. 2025-08-28 17:35:51 -07:00
init Significant patch series in this pull request: 2025-08-03 16:23:09 -07:00
io_uring io_uring: clear ->async_data as part of normal init 2025-08-21 13:54:01 -06:00
ipc vfs-6.17-rc1.mmap_prepare 2025-07-28 13:43:25 -07:00
kernel dma-mapping fixes for Linux 6.17 2025-08-28 16:04:14 -07:00
lib Crypto library fixes for v6.17-rc3 2025-08-21 04:54:01 -07:00
LICENSES LICENSES: Replace the obsolete address of the FSF in the GFDL-1.2 2025-07-24 11:15:39 +02:00
mm memblock fixes for v6.17-rc4 2025-08-28 15:46:06 -07:00
net Some fixes for the current cycle: 2025-08-29 13:35:13 -07:00
rust Driver core fixes for 6.16-rc3 2025-08-23 09:04:32 -04:00
samples Significant patch series in this pull request: 2025-08-03 16:23:09 -07:00
scripts Kbuild updates for v6.17 2025-08-06 07:32:52 +03:00
security + Features 2025-08-04 08:17:28 -07:00
sound ALSA: usb-audio: Use correct sub-type for UAC3 feature unit validation 2025-08-21 17:10:14 +02:00
tools netfilter: nft_flowtable.sh: re-run with random mtu sizes 2025-08-29 18:53:53 -07:00
usr usr/include: openrisc: don't HDRTEST bpf_perf_event.h 2025-05-12 15:03:17 +09:00
virt Merge tag 'kvm-x86-no_assignment-6.17' of https://github.com/kvm-x86/linux into HEAD 2025-07-29 08:36:42 -04:00
.clang-format Linux 6.15-rc5 2025-05-06 16:39:25 +10:00
.clippy.toml rust: clean Rust 1.88.0's warning about clippy::disallowed_macros configuration 2025-05-07 00:11:47 +02:00
.cocciconfig
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: Retire Ralf Baechle 2024-11-12 15:48:59 +01:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore gitignore: allow .pylintrc to be tracked 2025-07-02 17:10:04 -06:00
.mailmap .mailmap: add entry for Easwar Hariharan 2025-08-19 16:35:55 -07:00
.pylintrc docs: add a .pylintrc file with sys path for docs scripts 2025-04-09 12:10:33 -06:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: retire Boris from TLS maintainers 2025-08-26 17:36:01 -07:00
Kbuild drm: ensure drm headers are self-contained and pass kernel-doc 2025-02-12 10:44:43 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS Including fixes from Bluetooth. 2025-08-28 17:35:51 -07:00
Makefile Linux 6.17-rc3 2025-08-24 12:04:12 -04:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.