[PATCH v9 13/39] dyndbg: reduce verbose/debug clutter

From: Jim Cromie via B4 Relay

Date: Tue Sep 08 2026 - 21:02:14 EST


From: Jim Cromie <jim.cromie@xxxxxxxxx>

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.

Unmatched query diagnostics are intentionally restricted to verbose
level 3 (v3pr_info_dq) to reduce dmesg output clutter on standard
verbose levels (verbose=1 and verbose=2), aligning with the overall
de-cluttering of dynamic debug logging.

Signed-off-by: Jim Cromie <jim.cromie@xxxxxxxxx>
Reviewed-by: Louis Chauvet <louis.chauvet@xxxxxxxxxxx>
---
v7: update fingerprints of grammar-errs changed here
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.
---
lib/dynamic_debug.c | 24 +++----
.../selftests/dynamic_debug/dyndbg_selftest.sh | 84 +++++++++++-----------
2 files changed, 52 insertions(+), 56 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 43850ff5ccc3..2a69f86f973e 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;
@@ -283,9 +283,6 @@ 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;
}

@@ -494,7 +491,6 @@ static int ddebug_parse_query(char *words[], int nwords,
*/
query->module = modname;

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

@@ -518,7 +514,6 @@ 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--) {
@@ -532,7 +527,6 @@ 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) {
@@ -548,7 +542,7 @@ 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;
}
@@ -577,7 +571,7 @@ 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;
}
@@ -600,7 +594,10 @@ 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) {
@@ -1167,11 +1164,10 @@ 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) {
diff --git a/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh b/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
index bf02c505f1b5..e9f9db35fb7f 100755
--- a/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
+++ b/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
@@ -615,48 +615,48 @@ modular_tests=(
# ==============================================================================
function GOLDEN_RECORDS {
cat << 'EOF' | {
-#K= bb85d28739876b0fdf1eb426baae8ef7 FT_grammar_errs.1
-#K= 9c405e06fcea50284df82d1ae9692403 FT_grammar_errs.2
-#K= 0b0d9b0e6f4c45c7d75d699fd3b6aa93 FT_grammar_errs.3
-#K= e008644e159c2a9d99a8d0806c06e71e FT_grammar_errs.4
-#K= 5750ed178633f9a68623f928c093d16e FT_grammar_errs.5
-#K= 2cd51e5e3c3e2501544524bed0fab620 FT_grammar_errs.6
-#K= 3e1eba65bd936e1276c7e1d76b399595 FT_grammar_errs.7
-#K= e3ac86676e309d4e72ff3da287736c29 FT_grammar_errs.8
-#K= 466d325c23519119f754fa7860bae7c6 FT_grammar_errs.9
-#K= 51c489366cd86c16280858b95adf34ac FT_grammar_errs.10
-#K= dfc632c6c0cd6206b6141dbc5fb989db FT_grammar_errs.11
-#K= 69650fc26e97a78082bd851eb4a5c83b FT_grammar_errs.12
-#K= 5cfe5665962a482f416836793067f2a2 FT_grammar_errs.13
-#K= 661cc9a2d8d3c381bfeae41392432575 FT_grammar_errs.14
-#K= 5dd0accf9be37ce2f4bf697e9bdebe30 FT_grammar_errs.15
-#K= bd8d9cf661c9aca54dac93c74cfc1501 FT_grammar_errs.16
-#K= e991391048f2fdffaaed99ba36b787ed FT_grammar_errs.17
-#K= 82d99278f471ebfbf47eeb19898525cf FT_grammar_errs.18
-#K= f3f088fa7d276981bf2898c048087f76 FT_grammar_errs.19
-#K= 984ecc198e0fa9fc91bc31caf7da2a5d FT_grammar_errs.20
-#K= 76c8a33c585d414fcc3f1c8b5ea5b4b3 FT_grammar_errs.21
-#K= 90cfc66e9d61f5c448353b97baa99145 FT_grammar_errs.22
-#K= 37a51dfd6e84cb64b69d3a0e23e68ceb FT_grammar_errs.23
-#K= 3aefa325b63742710b45e4531152c9d8 FT_grammar_errs.24
-#K= bc8d2c23282cd6834879bc1f1b303d05 FT_grammar_errs.25
-#K= 092ec5530d875be1dc96ad4202fc7dc3 FT_grammar_errs.26
-#K= 98caa2677e9070953a852b27ab57861e FT_grammar_errs.27
-#K= 8d755baa707c7b3b67491bf84708ef08 FT_grammar_errs.28
-#K= 5dd0accf9be37ce2f4bf697e9bdebe30 FT_grammar_errs.29
-#K= 2e37642dc8aee3d04b8a54a76b3b891c FT_grammar_errs.30
-#K= 593c8b4c41932e3bde564a0008627ced FT_grammar_errs.31
-#K= 85a2a0bee8d0cd10f883aa5477d62efb FT_grammar_errs.32
-#K= f3f088fa7d276981bf2898c048087f76 FT_grammar_errs.33
-#K= 629f6a7e379e02f38c543cdb48e3b84f FT_grammar_errs.34
-#K= d9f0cffb0898c54690735a71b0d4f3bf FT_grammar_errs.35
-#K= 4cf728b6a32043ea5336a14d0c435312 FT_grammar_errs.36
-#K= a11ae3f86f4e5f539fd6168d318f74b4 FT_grammar_errs.37
-#K= c7d3830b0391f6a773205066b64e15f9 FT_grammar_errs.38
-#K= 5c506ea2bfd050439b580b91543e9be7 FT_grammar_errs.39
-#K= a257660007408f7bb0cb43c99b1c7bb8 FT_grammar_errs.40
-#K= 0082939f100300a7b327b143cf40cb43 FT_grammar_errs.41
-#K= 657ac4360f978687ad25a705b2bb89f1 FT_grammar_errs.42
+#K= f3dbd5afb9aa1750f93275b634499e22 FT_grammar_errs.1
+#K= 200c01632c52a63f6d186da1c6460740 FT_grammar_errs.2
+#K= 7d7141900ce6e32f15c99202309c63a4 FT_grammar_errs.3
+#K= 1bb798a5831d0119789d424ef6cb55c4 FT_grammar_errs.4
+#K= 5edd66e308b2792d5694df86c07a3eaf FT_grammar_errs.5
+#K= 6f87d92ffe0812550f43287127c6f2b9 FT_grammar_errs.6
+#K= c0eb05b58a008c722e091e1ae74440ec FT_grammar_errs.7
+#K= 911929ec0e2ffc1f13822b479dec6805 FT_grammar_errs.8
+#K= c1407512376369d2e591a4b25a4b607a FT_grammar_errs.9
+#K= 2046abda72725ea06fe339d5f364f1c9 FT_grammar_errs.10
+#K= b72f7fccf76f8a5bee47a05d7bb545fb FT_grammar_errs.11
+#K= 98e2bd3e4f3da58536496a38ec3e6238 FT_grammar_errs.12
+#K= b371c6ba52503d037dbc43da788af8be FT_grammar_errs.13
+#K= cb8288d607b0c5282125852f3ab05107 FT_grammar_errs.14
+#K= 9346a310c4ad57cc3746afbace702c3e FT_grammar_errs.15
+#K= 533d27af85eed3c0fd2eaec961982a36 FT_grammar_errs.16
+#K= 114e0632585e205a3347c82bac7d79f2 FT_grammar_errs.17
+#K= 73f5c173bafdfb9674b5ecce77db3354 FT_grammar_errs.18
+#K= 0fc110d078f60eacdd389e5975ba18d9 FT_grammar_errs.19
+#K= 815a1c52f365510c644450bb80c07e72 FT_grammar_errs.20
+#K= 621e3cd81b553973cb40a935bb9298f1 FT_grammar_errs.21
+#K= 581222901232344ade18bbda58302c48 FT_grammar_errs.22
+#K= ea0aae3e01b3bb22eb8ad7acd327b371 FT_grammar_errs.23
+#K= 8f28189bff62a3d5ed16f537d41a725a FT_grammar_errs.24
+#K= 19c425e5d3a645b5dc5e23758ba0f4a1 FT_grammar_errs.25
+#K= 75415542333f2250f0e060a54dae50f8 FT_grammar_errs.26
+#K= 0955815c0e595ab2206e25aa31fe1ef2 FT_grammar_errs.27
+#K= 3ff4c0b60db33e44c3cd6f0e14f81e3e FT_grammar_errs.28
+#K= 9346a310c4ad57cc3746afbace702c3e FT_grammar_errs.29
+#K= 7aaf0a16c287e66b62e11298ee160b34 FT_grammar_errs.30
+#K= 06350c62105b537cdd0c67736b29727d FT_grammar_errs.31
+#K= 6ef0ec01805c8719d828553098f95377 FT_grammar_errs.32
+#K= 0fc110d078f60eacdd389e5975ba18d9 FT_grammar_errs.33
+#K= 72203b2d88d0617cd5c659d3b80e26f9 FT_grammar_errs.34
+#K= 6ecb03736d5cddb7ab2aaff49d561be9 FT_grammar_errs.35
+#K= eaa989336cb7c96c13ef4a3964fc6898 FT_grammar_errs.36
+#K= 5b624d9c133d7bb4f5370c3ce06929ed FT_grammar_errs.37
+#K= 127275739b1fe04c84eedad28ec154f6 FT_grammar_errs.38
+#K= 3e2fd15a7e8c0583bc5066524bc50508 FT_grammar_errs.39
+#K= 781995971d28f732a792522f3c56cdd3 FT_grammar_errs.40
+#K= 6614a677d9f9ac09d9825b4e989d2c42 FT_grammar_errs.41
+#K= 70de9afed457a6be9f9c3c81cbd6d4d5 FT_grammar_errs.42
#K= 6e8599556a312200fb6d484565b6c52f FT_basic_queries.1
#K= db17180b59444e5e34a8fc20c40e4530 FT_basic_queries.2
#K= f7bd56bd407ff255ef2e3b5fb093ae6a FT_basic_queries.3

--
2.55.0