[PATCH v4 13/25] dyndbg: reduce verbose/debug clutter

From: Jim Cromie

Date: Tue Jun 02 2026 - 18:53:36 EST


currently, for verbose=3, these are logged (blank lines for clarity):

dyndbg: query 0: "class DRM_UT_CORE +p" mod:*
dyndbg: split into words: "class" "DRM_UT_CORE" "+p"

dyndbg: op='+'
dyndbg: flags=0x1
dyndbg: *flagsp=0x1 *maskp=0xffffffff

dyndbg: parsed: func="" file="" module="" format="" lineno=0-0 class=...
dyndbg: no matches for query
dyndbg: no-match: func="" file="" module="" format="" lineno=0-0 class=...
dyndbg: processed 1 queries, with 0 matches, 0 errs

That is excessive, so this patch:
- shrinks 3 lines of 2nd stanza to single line
- drops 1st 2 lines of 3rd stanza
3rd line is like 1st, with result, not procedure.
2nd line is just status, retold in 4th, with more info.

New output:

dyndbg: query 0: "class DRM_UT_CORE +p"
dyndbg: split into words: "class" "DRM_UT_CORE" "+p"
dyndbg: op='+' flags=0x1 maskp=0xffffffff
dyndbg: processed 1 queries, with 0 matches, 0 errs

Also drop several verbose=3 messages in ddebug_add_module

When modprobing a module, dyndbg currently logs/says "add-module", and
then "skipping" if the module has no prdbgs. Instead just check 1st
and return quietly.

no functional change

Signed-off-by: Jim Cromie <jim.cromie@xxxxxxxxx>
Reviewed-by: Louis Chauvet <louis.chauvet@xxxxxxxxxxx>
---
v4: rename vpr_dq_info to v3pr_dq_info to tell its active logging level
adjust some vX levels per doc'd intentions
v2: RvB after SoB

trivial change to verbose-debug output line to output the actual
"module" keyword rather than "mod:", and do so only when the module is
constrained by the callchain (ie as part of a modprobe).

was: query X: "(keyword value)* [+-=]flags" mod:*
now: query X: "(keyword value)* [+-=]flags"
or query X: module FOO "keyword value)* [+-=]flags"

IOW, adjust output to reflect the input grammar more closely.

drop-info-parsed

vinfo-applied-nomatch

dyndbg: tweak verbose-levels per doc
---
lib/dynamic_debug.c | 24 ++++++++++--------------
1 file changed, 10 insertions(+), 14 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 0377d9f8dcd1..a967e3ef1dbc 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -128,7 +128,7 @@ do { \
#define v3pr_info(fmt, ...) vnpr_info(3, fmt, ##__VA_ARGS__)
#define v4pr_info(fmt, ...) vnpr_info(4, fmt, ##__VA_ARGS__)

-static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
+static void v3pr_info_dq(const struct ddebug_query *query, const char *msg)
{
/* trim any trailing newlines */
int fmtlen = 0;
@@ -276,9 +276,6 @@ static int ddebug_change(const struct ddebug_query *query,
}
mutex_unlock(&ddebug_lock);

- if (!nfound && verbose)
- pr_info("no matches for query\n");
-
return nfound;
}

@@ -487,7 +484,6 @@ static int ddebug_parse_query(char *words[], int nwords,
*/
query->module = modname;

- vpr_info_dq(query, "parsed");
return 0;
}

@@ -511,7 +507,6 @@ static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers)
pr_err("bad flag-op %c, at start of %s\n", *str, str);
return -EINVAL;
}
- v3pr_info("op='%c'\n", op);

for (; *str ; ++str) {
for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) {
@@ -525,7 +520,6 @@ static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers)
return -EINVAL;
}
}
- v3pr_info("flags=0x%x\n", modifiers->flags);

/* calculate final flags, mask based upon op */
switch (op) {
@@ -541,7 +535,7 @@ static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers)
modifiers->flags = 0;
break;
}
- v3pr_info("*flagsp=0x%x *maskp=0x%x\n", modifiers->flags, modifiers->mask);
+ v3pr_info("op='%c' flags=0x%x maskp=0x%x\n", op, modifiers->flags, modifiers->mask);

return 0;
}
@@ -570,7 +564,7 @@ static int ddebug_exec_query(char *query_string, const char *modname)
}
/* actually go and implement the change */
nfound = ddebug_change(&query, &modifiers);
- vpr_info_dq(&query, nfound ? "applied" : "no-match");
+ v3pr_info_dq(&query, nfound ? "applied" : "no-match");

return nfound;
}
@@ -593,7 +587,10 @@ static int ddebug_exec_queries(char *query, const char *modname)
if (!query || !*query || *query == '#')
continue;

- vpr_info("query %d: \"%s\" mod:%s\n", i, query, modname ?: "*");
+ if (modname)
+ v2pr_info("query %d: module %s \"%s\"\n", i, modname, query);
+ else
+ v2pr_info("query %d: \"%s\"\n", i, query);

rc = ddebug_exec_query(query, modname);
if (rc < 0) {
@@ -1159,11 +1156,10 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
{
struct ddebug_table *dt;

- v3pr_info("add-module: %s.%d sites\n", modname, di->num_descs);
- if (!di->num_descs) {
- v3pr_info(" skip %s\n", modname);
+ if (!di->num_descs)
return 0;
- }
+
+ v3pr_info("add-module: %s %d sites\n", modname, di->num_descs);

dt = kzalloc_obj(*dt);
if (dt == NULL) {

--
2.54.0