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_ * Patch to covert a bitwise operation into boolean * 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 leitao@debian.org --- Changes in v2: - Add an extra patch to convert the comparison more stable. (Paolo) - Changed the argument of a function (Simon) - Removed the warn on `current == NULLL` since it shouldn't be the case. (Simon and Paolo) - Link to v1: https://lore.kernel.org/r/20250221-netcons_current-v1-0-21c86ae8fc0d@debian....
--- Breno Leitao (8): netconsole: prefix CPU_NR sysdata feature with SYSDATA_ netconsole: Make boolean comparison consistent 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 | 95 ++++++++++++++++++---- .../selftests/drivers/net/netcons_sysdata.sh | 51 ++++++++++-- 3 files changed, 153 insertions(+), 21 deletions(-) --- base-commit: 56794b5862c5a9aefcf2b703257c6fb93f76573e change-id: 20250217-netcons_current-2c635fa5beda prerequisite-change-id: 20250212-netdevsim-258d2d628175:v3 prerequisite-patch-id: 4ecfdbc58dd599d2358655e4ad742cbb9dde39f3
Best regards,