[RFC] sysfs kobject that doesn't trigger hotplug events

John Zielinski
2004-05-19T02:12:02Z

[-- Attachment #1: Type: text/plain, Size: 728 bytes --]

I'm adding some data structures to a device and want them to appear
under that device in sysfs in subdirectories. These data structures are
linked together in a tree like layout so it would make sense to have
them have a subdirectory tree representing them. These data structures
have a kobject for reference counting and I can use kobject_add and
kobject_del to add them to the sysfs tree.

Looking through the kobject.c code I noticed that this would create a
lot of hotplug events which would burn up a bit of processor time.
These events are not necessary as these are not device kobjects. I've
enclosed a patch to my solution for this. I'd like to know if there are
any side effects with this method.

John

[-- Attachment #2: kobject_no_hotplug --]
[-- Type: text/plain, Size: 826 bytes --]

diff -urNX dontdiff linux-2.6.6/include/linux/kobject.h linux/include/linux/kobject.h
--- linux-2.6.6/include/linux/kobject.h 2004-05-09 22:31:59.000000000 -0400
+++ linux/include/linux/kobject.h 2004-05-18 20:29:43.000000000 -0400
@@ -62,6 +62,7 @@
void (*release)(struct kobject *);
struct sysfs_ops * sysfs_ops;
struct attribute ** default_attrs;
+ int no_hotplug;
};

diff -urNX dontdiff linux-2.6.6/lib/kobject.c linux/lib/kobject.c
--- linux-2.6.6/lib/kobject.c 2004-05-09 22:33:19.000000000 -0400
+++ linux/lib/kobject.c 2004-05-18 20:50:42.000000000 -0400
@@ -203,6 +203,9 @@
{
struct kobject * top_kobj = kobj;

+ if (kobj->ktype && kobj->ktype->no_hotplug)
+ return;
+
/* If this kobj does not belong to a kset,
try to find a parent that does. */
if (!top_kobj->kset && top_kobj->parent) {