[PATCH v8 16/43] dyndbg: reduce verbose/debug clutter

[Jim Cromie via B4 Relay <devnull+jim.cromie.gmail.com@kernel.org>]

From: Jim Cromie <jim.cromie@gmail.com>

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@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
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 ++++++++++--------------
 1 file changed, 10 insertions(+), 14 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 122c2c9a1254..b2892be2de36 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) {

-- 
2.55.0