Dyndbg is required to enable prdbgs at compile-time if DEBUG is defined. Show this works; add the defn to test_dynamic_debug.c, and manually inspect/verify its effect at module load: [ 15.292810] dyndbg: module:test_dynamic_debug attached 4 classes [ 15.293189] dyndbg: 32 debug prints in module test_dynamic_debug [ 15.293715] test_dd: init start [ 15.293716] test_dd: doing categories [ 15.293716] test_dd: LOW msg ... [ 15.293733] test_dd: L6 msg [ 15.293733] test_dd: L7 msg [ 15.293733] test_dd: init done NOTES: As is observable above, define DEBUG enables all prdbgs, including those in mod_init-fn, and more notably, the "class"d ones (callsites with non-default class_ids). This differs from the >control interface, which in order to properly protect a client's class'd prdbgs, requires a "class FOO" in queries to change them. Note that the DEBUG is in the module source file. This yields an occaisional surprise; the following disables all the compile-time enabled plain prdbgs, but leaves the class'd ones enabled. :#> modprobe test_dynamic_debug dyndbg==_ Signed-off-by: Jim Cromie <jim.cromie@xxxxxxxxx> --- lib/test_dynamic_debug.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c index a01f0193a419..9d48689dc0ab 100644 --- a/lib/test_dynamic_debug.c +++ b/lib/test_dynamic_debug.c @@ -8,6 +8,8 @@ #define pr_fmt(fmt) "test_dd: " fmt +#define DEBUG + #include <linux/module.h> /* run tests by reading or writing sysfs node: do_prints */ -- 2.38.1