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From:   Jim Cromie <jim.cromie@gmail.com>
To:     Jason Baron <jbaron@akamai.com>, linux-kernel@vger.kernel.org
Cc:     linux-mm@kvack.org, Jim Cromie <jim.cromie@gmail.com>
Subject: [RFC PATCH v5 15/28] dyndbg: ddebug_add_module avoid adding empty modules
Date:   Tue, 11 May 2021 12:50:44 -0600
Message-Id: <20210511185057.3815777-16-jim.cromie@gmail.com>
In-Reply-To: <20210511185057.3815777-1-jim.cromie@gmail.com>
References: <20210511185057.3815777-1-jim.cromie@gmail.com>
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Don't create ddebug_table's for modules with 0 callsites.  This saves
memory, and avoids creating ddebug_tables with questionable contents,
which are then iterated over for 'cat control'.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 lib/dynamic_debug.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 90bea97c0da1..77c5135879c2 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -1033,6 +1033,12 @@ int ddebug_add_module(struct _ddebug *tab, struct _ddebug_site *sites,
 {
 	struct ddebug_table *dt;
 
+	v3pr_info("add-module: %s.%d sites\n", modname, numdbgs);
+	if (!numdbgs) {
+		v3pr_info(" skip %s\n", modname);
+		return 0;
+	}
+
 	dt = kzalloc(sizeof(*dt), GFP_KERNEL);
 	if (dt == NULL) {
 		pr_err("error adding module: %s\n", modname);
-- 
2.31.1