linux-next.git/Documentation/admin-guide/dynamic-debug-howto.rst, branch master

docs/dyndbg: explain flags parse 1st

2026-06-01T19:11:20+00:00

When writing queries to >control, flags are parsed 1st, since they are the only required field, and they require specific compositions. So if the flags draw an error (on those specifics), then keyword errors aren't reported. This can be mildly confusing/annoying, so explain it instead. cc: linux-doc@vger.kernel.org Reviewed-by: Louis Chauvet Signed-off-by: Jim Cromie Signed-off-by: Jonathan Corbet Message-ID: <20260502-dyndbg-doc-v1-2-67cc4a93a77e@gmail.com>

docs/dyndbg: update examples \012 to \n

2026-06-01T19:11:20+00:00

commit 47ea6f99d06e ("dyndbg: use ESCAPE_SPACE for cat control") changed the control-file to display format strings with "\n" rather than "\012". Update the docs to match the new reality. Reviewed-by: Louis Chauvet Tested-by: Louis Chauvet Signed-off-by: Jim Cromie Signed-off-by: Jonathan Corbet Message-ID: <20260502-dyndbg-doc-v1-1-67cc4a93a77e@gmail.com>

dynamic_debug: add support for print stack

2025-11-12T18:00:16+00:00

In practical problem diagnosis, especially during the boot phase, it is often desirable to know the call sequence. However, currently, apart from adding print statements and recompiling the kernel, there seems to be no good alternative. If dynamic_debug supported printing the call stack, it would be very helpful for diagnosing issues. This patch add support '+d' for dump stack. Link: https://lkml.kernel.org/r/20251025080003.312536-1-yebin@huaweicloud.com Signed-off-by: Ye Bin Cc: Jason Baron Cc: Jim Cromie Signed-off-by: Andrew Morton

Documentation: add reference from dynamic debug to loglevel kernel params

2024-07-09T14:57:52+00:00

This is useful information for somebody who has managed to dig into enabling debug output, but is wondering why there is no such output appearing on the console. Signed-off-by: Daniel Lublin Signed-off-by: Jonathan Corbet Link: https://lore.kernel.org/r/4633bdb82c1c7c014d79840887878624a55c59f8.1720533043.git.daniel@lublin.se

Documentation: Remove redundant file names from examples

2023-12-15T16:15:05+00:00

Since most examples use the ddcmd alias, remove the redundant file names Signed-off-by: Rex Nie Signed-off-by: Jonathan Corbet Link: https://lore.kernel.org/r/20231213073735.2850-1-rex.nie@jaguarmicro.com

Documentation: fix typo in dynamic-debug howto

2023-10-23T02:37:17+00:00

Signed-off-by: Jade Lovelace Signed-off-by: Jonathan Corbet Message-ID: <20231019231655.3162225-1-lists@jade.fyi>

dyndbg: add source filename to prefix

2023-08-04T13:28:41+00:00

Printing the line number without the file is of limited usefulness. Knowing the filename also makes it also easier to relate the logged information to the controlfile. Example: # modprobe test_dynamic_debug # echo 'file test_dynamic_debug.c =pfsl' > /proc/dynamic_debug/control # echo 1 > /sys/module/test_dynamic_debug/parameters/do_prints # dmesg | tail -2 [ 71.802212] do_cats:lib/test_dynamic_debug.c:103: test_dd: doing categories [ 71.802227] do_levels:lib/test_dynamic_debug.c:123: test_dd: doing levels Signed-off-by: Thomas Weißschuh Acked-by: Jim Cromie Acked-by: Jason Baron Reviewed-by: Luis Chamberlain Link: https://lore.kernel.org/r/20230709-dyndbg-filename-v2-3-fd83beef0925@weissschuh.net Signed-off-by: Greg Kroah-Hartman

Documentation: admin-guide: correct spelling

2023-02-02T18:04:42+00:00

Correct spelling problems for Documentation/admin-guide/ as reported by codespell. Signed-off-by: Randy Dunlap Reviewed-by: Mukesh Ojha Cc: Tejun Heo Cc: Zefan Li Cc: Johannes Weiner Cc: cgroups@vger.kernel.org Cc: Alasdair Kergon Cc: Mike Snitzer Cc: dm-devel@redhat.com Cc: Mauro Carvalho Chehab Cc: linux-media@vger.kernel.org Cc: linux-mm@kvack.org Link: https://lore.kernel.org/r/20230129231053.20863-2-rdunlap@infradead.org Signed-off-by: Jonathan Corbet

doc-dyndbg: edit dynamic-debug-howto for brevity, audience

2022-09-07T15:04:49+00:00

Rework/modernize docs: - use /proc/dynamic_debug/control in examples its *always* there (when dyndbg is config'd), even when is not. drop talk, its a distraction here. - alias ddcmd='echo $* > /proc/dynamic_debug/control focus on args: declutter, hide boilerplate, make pwd independent. - swap sections: Viewing before Controlling. control file as Catalog. - focus on use by a system administrator add an alias to make examples more readable drop grep-101 lessons, admins know this. - use init/main.c as 1st example, thread it thru doc where useful. everybodys kernel boots, runs these. - add *prdbg* api section to the bottom of the file, its for developers more than admins. move list of api functions there. - simplify - drop extra words, phrases, sentences. - add "decorator" flags line to unify "prefix", trim fmlt descriptions CC: linux-doc@vger.kernel.org Signed-off-by: Jim Cromie Link: https://lore.kernel.org/r/20220904214134.408619-20-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman

doc-dyndbg: describe "class CLASS_NAME" query support

2022-09-07T15:04:49+00:00

Add an explanation of the new "class CLASS_NAME" syntax and meaning, noting that the module determines if CLASS_NAME applies to it. Signed-off-by: Jim Cromie Link: https://lore.kernel.org/r/20220904214134.408619-19-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman