driver-core: skip uevent generation when nobody is listening

Most network namespaces unlikely have listeners to uevents, and should benefit from skipping all the string copies. Cc: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

driver-core: skip uevent generation when nobody is listening
Most network namespaces unlikely have listeners to uevents, and should benefit from skipping all the string copies. Cc: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Kay Sievers · Greg Kroah-Hartman
1 parent cf6a2eacbc
Showing 1 changed file with 3 additions and 0 deletions Side-by-side Diff
lib/kobject_uevent.c
@@ -259,6 +259,9 @@
 		struct sk_buff *skb;
 		size_t len;
  
+		if (!netlink_has_listeners(uevent_sock, 1))
+			continue;
+
 		/* allocate message with the maximum possible size */
 		len = strlen(action_string) + strlen(devpath) + 2;
 		skb = alloc_skb(len + env->buflen, GFP_KERNEL);
...	...	@@ -259,6 +259,9 @@
259	259	struct sk_buff *skb;
260	260	size_t len;
261	261
	262	+ if (!netlink_has_listeners(uevent_sock, 1))
	263	+ continue;
	264	+
262	265	/* allocate message with the maximum possible size */
263	266	len = strlen(action_string) + strlen(devpath) + 2;
264	267	skb = alloc_skb(len + env->buflen, GFP_KERNEL);