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Jakub Kicinski e316dd1cf1 net: don't dump stack on queue timeout
The top syzbot report for networking (#14 for the entire kernel)
is the queue timeout splat. We kept it around for a long time,
because in real life it provides pretty strong signal that
something is wrong with the driver or the device.

Removing it is also likely to break monitoring for those who
track it as a kernel warning.

Nevertheless, WARN()ings are best suited for catching kernel
programming bugs. If a Tx queue gets starved due to a pause
storm, priority configuration, or other weirdness - that's
obviously a problem, but not a problem we can fix at
the kernel level.

Bite the bullet and convert the WARN() to a print.

Before:

  NETDEV WATCHDOG: eni1np1 (netdevsim): transmit queue 0 timed out 1975 ms
  WARNING: CPU: 0 PID: 0 at net/sched/sch_generic.c:525 dev_watchdog+0x39e/0x3b0
  [... completely pointless stack trace of a timer follows ...]

Now:

  netdevsim netdevsim1 eni1np1: NETDEV WATCHDOG: CPU: 0: transmit queue 0 timed out 1769 ms

Alternatively we could mark the drivers which syzbot has
learned to abuse as "print-instead-of-WARN" selectively.

Reported-by: syzbot+d55372214aff0faa1f1f@syzkaller.appspotmail.com
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-11-15 10:25:12 +00:00
Documentation Including fixes from netfilter and bpf. 2023-11-09 17:09:35 -08:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
arch IOMMU Updates for Linux v6.7 2023-11-09 13:37:28 -08:00
block As usual, lots of singleton and doubleton patches all over the tree and 2023-11-02 20:53:31 -10:00
certs This update includes the following changes: 2023-11-02 16:15:30 -10:00
crypto This push fixes a regression in ahash and hides the Kconfig sub-options for the jitter RNG. 2023-11-09 17:04:58 -08:00
drivers bnxt_en: Optimize xmit_more TX path 2023-11-15 10:07:40 +00:00
fs NFS client updates for Linux 6.7 2023-11-08 13:39:16 -08:00
include Including fixes from netfilter and bpf. 2023-11-09 17:09:35 -08:00
init As usual, lots of singleton and doubleton patches all over the tree and 2023-11-02 20:53:31 -10:00
io_uring io_uring-futex-2023-10-30 2023-11-01 11:25:08 -10:00
ipc Many singleton patches against the MM code. The patch series which are 2023-11-02 19:38:47 -10:00
kernel Including fixes from netfilter and bpf. 2023-11-09 17:09:35 -08:00
lib Second bcachefs pull request for 6.7-rc1 2023-11-07 11:38:38 -08:00
mm memblock: report failures when memblock_can_resize is not set 2023-11-08 09:40:13 -08:00
net net: don't dump stack on queue timeout 2023-11-15 10:25:12 +00:00
rust Kbuild updates for v6.7 2023-11-04 08:07:19 -10:00
samples Landlock updates for v6.7-rc1 2023-11-03 09:28:53 -10:00
scripts Kbuild updates for v6.7 2023-11-04 08:07:19 -10:00
security + Features 2023-11-03 09:48:17 -10:00
sound As usual, lots of singleton and doubleton patches all over the tree and 2023-11-02 20:53:31 -10:00
tools Including fixes from netfilter and bpf. 2023-11-09 17:09:35 -08:00
usr arch: Remove Itanium (IA-64) architecture 2023-09-11 08:13:17 +00:00
virt ARM: 2023-09-07 13:52:20 -07:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: rpm-pkg: generate kernel.spec in rpmbuild/SPECS/ 2023-10-03 20:49:09 +09:00
.mailmap As usual, lots of singleton and doubleton patches all over the tree and 2023-11-02 20:53:31 -10:00
.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 USB: Remove Wireless USB and UWB documentation 2023-08-09 14:17:32 +02:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: update lists.linuxfoundation.org migrated lists 2023-11-08 12:44:27 -08:00
Makefile Kbuild updates for v6.7 2023-11-04 08:07:19 -10:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README

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 Restructured Text 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.