[net-next,0/7] netconsole: Add taskname sysdata support

Message

Breno Leitao Feb. 21, 2025, 1:52 p.m. UTC

This patchset introduces a new feature to the netconsole extradata
subsystem that enables the inclusion of the current task's name in the
sysdata output of netconsole messages.

This enhancement is particularly valuable for large-scale deployments,
such as Meta's, where netconsole collects messages from millions of
servers and stores them in a data warehouse for analysis. Engineers
often rely on these messages to investigate issues and assess kernel
health.

One common challenge we face is determining the context in which
a particular message was generated. By including the task name
(task->comm) with each message, this feature provides a direct answer to
the frequently asked question: "What was running when this message was
generated?"

This added context will significantly improve our ability to diagnose
and troubleshoot issues, making it easier to interpret output of
netconsole.

The patchset consists of seven patches that implement the following changes:

 * Refactor CPU number formatting into a separate function
 * Prefix CPU_NR sysdata feature with SYSDATA_
 * Add configfs controls for taskname sysdata feature
 * Add taskname to extradata entry count
 * Add support for including task name in netconsole's extra data output
 * Document the task name feature in Documentation/networking/netconsole.rst
 * Add test coverage for the task name feature to the existing sysdata selftest script

These changes allow users to enable or disable the task name feature via
configfs and provide additional context for kernel messages by showing
which task generated each console message.

I have tested these patches on some servers and they seem to work as
expected.

Signed-off-by: Breno Leitao <[e-mail]>
---
Breno Leitao (7):
      netconsole: prefix CPU_NR sysdata feature with SYSDATA_
      netconsole: refactor CPU number formatting into separate function
      netconsole: add taskname to extradata entry count
      netconsole: add configfs controls for taskname sysdata feature
      netconsole: add task name to extra data fields
      netconsole: docs: document the task name feature
      netconsole: selftest: add task name append testing

 Documentation/networking/netconsole.rst            | 28 +++++++
 drivers/net/netconsole.c                           | 98 ++++++++++++++++++----
 .../selftests/drivers/net/netcons_sysdata.sh       | 51 +++++++++--
 3 files changed, 156 insertions(+), 21 deletions(-)
---
base-commit: bb3bb6c92e5719c0f5d7adb9d34db7e76705ac33
change-id: 20250217-netcons_current-2c635fa5beda
prerequisite-change-id: 20250212-netdevsim-258d2d628175:v3
prerequisite-patch-id: 4ecfdbc58dd599d2358655e4ad742cbb9dde39f3

Best regards,