it's not at all clear to me what the value is in using a kset when writing some kernel code. i can see the example program, samples/kobject/kset-example.c, but that program doesn't seem to demonstrate what the purpose is of the kset created. as another example, consider the different filesystem implementations under the fs/ directory, and grep to see who uses what to create the appropriate entry under /sys/fs/: $ grep -r "create_and_add" * 9p/v9fs.c: v9fs_kobj = kobject_create_and_add("9p", fs_kobj); btrfs/sysfs.c: btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj); configfs/mount.c: config_kobj = kobject_create_and_add("config", kernel_kobj); debugfs/inode.c: debug_kobj = kobject_create_and_add("debug", kernel_kobj); dlm/lockspace.c: dlm_kset = kset_create_and_add("dlm", &dlm_uevent_ops, kernel_kobj); ecryptfs/main.c: ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj); exofs/sys.c: exofs_kset = kset_create_and_add("exofs", NULL, fs_kobj); exofs/sys.c: EXOFS_ERR("ERROR: kset_create_and_add exofs failed\n"); ext4/super.c: ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj); fscache/cache.c: cache->kobj = kobject_create_and_add(tagname, fscache_root); fscache/main.c: fscache_root = kobject_create_and_add("fscache", kernel_kobj); fuse/inode.c: fuse_kobj = kobject_create_and_add("fuse", fs_kobj); fuse/inode.c: connections_kobj = kobject_create_and_add("connections", fuse_kobj); gfs2/sys.c: gfs2_kset = kset_create_and_add("gfs2", &gfs2_uevent_ops, fs_kobj); namespace.c: fs_kobj = kobject_create_and_add("fs", NULL); ocfs2/cluster/sys.c: o2cb_kset = kset_create_and_add("o2cb", NULL, fs_kobj); ocfs2/stackglue.c: ocfs2_kset = kset_create_and_add("ocfs2", NULL, fs_kobj); $ as you can see, some use kobject_create_and_add() while others use kset_create_and_add(), and it's not clear to me what the difference is in *why* one was chosen over the other. thoughts? i'm sure there's a simple distinction i'm just missing here. rday -- ======================================================================== Robert P. J. Day Ottawa, Ontario, CANADA http://crashcourse.ca Twitter: http://twitter.com/rpjday LinkedIn: http://ca.linkedin.com/in/rpjday ========================================================================