kobject: Reorder fields in 'struct kobject'

Group some variables based on their sizes to reduce hole and avoid padding.
On x86_64, this shrinks the size of 'struct kobject' from 256 to 244 bytes.

This structure is often included in some other structures. So these other
structures will also benefit from this 8 bytes saving.

This is especially nice for structure like 'cma_kobject' or 'class_dir'
that are now 256 bytes long. When they are kzalloc()'ed, 256 bytes are
allocated, instead of 512.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/6c7d1e3005dbec5483bdb9b7b60071175bf7bf70.1688811201.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/include/linux/kobject.h b/include/linux/kobject.h
index c392c81..c30affc 100644 (file)
--- a/include/linux/kobject.h
+++ b/include/linux/kobject.h
@@ -69,14 +69,16 @@ struct kobject {
        const struct kobj_type  *ktype;
        struct kernfs_node      *sd; /* sysfs directory entry */
        struct kref             kref;
-#ifdef CONFIG_DEBUG_KOBJECT_RELEASE
-       struct delayed_work     release;
-#endif
+
        unsigned int state_initialized:1;
        unsigned int state_in_sysfs:1;
        unsigned int state_add_uevent_sent:1;
        unsigned int state_remove_uevent_sent:1;
        unsigned int uevent_suppress:1;
+
+#ifdef CONFIG_DEBUG_KOBJECT_RELEASE
+       struct delayed_work     release;
+#endif
 };
 
 __printf(2, 3) int kobject_set_name(struct kobject *kobj, const char *name, ...);