From c25d1dfbd403209025df41a737f82ce8f43d93f5 Mon Sep 17 00:00:00 2001 From: Robin Holt Date: Wed, 29 Sep 2010 14:00:54 -0500 Subject: kobject: Introduce kset_find_obj_hinted. One call chain getting to kset_find_obj is: link_mem_sections() find_mem_section() kset_find_obj() This is done during boot. The memory sections were added in a linearly increasing order and link_mem_sections tends to utilize them in that same linear order. Introduce a kset_find_obj_hinted which is passed the result of the previous kset_find_obj which it uses for a quick "is the next object our desired object" check before falling back to the old behavior. Signed-off-by: Robin Holt To: Robert P. J. Day Reviewed-by: KAMEZAWA Hiroyuki Signed-off-by: Greg Kroah-Hartman --- lib/kobject.c | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) (limited to 'lib/kobject.c') diff --git a/lib/kobject.c b/lib/kobject.c index f07c57252e82..82dc34c095c2 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -745,18 +745,57 @@ void kset_unregister(struct kset *k) * take a reference and return the object. */ struct kobject *kset_find_obj(struct kset *kset, const char *name) +{ + return kset_find_obj_hinted(kset, name, NULL); +} + +/** + * kset_find_obj_hinted - search for object in kset given a predecessor hint. + * @kset: kset we're looking in. + * @name: object's name. + * @hint: hint to possible object's predecessor. + * + * Check the hint's next object and if it is a match return it directly, + * otherwise, fall back to the behavior of kset_find_obj(). Either way + * a reference for the returned object is held and the reference on the + * hinted object is released. + */ +struct kobject *kset_find_obj_hinted(struct kset *kset, const char *name, + struct kobject *hint) { struct kobject *k; struct kobject *ret = NULL; spin_lock(&kset->list_lock); + + if (!hint) + goto slow_search; + + /* end of list detection */ + if (hint->entry.next == kset->list.next) + goto slow_search; + + k = container_of(hint->entry.next, struct kobject, entry); + if (!kobject_name(k) || strcmp(kobject_name(k), name)) + goto slow_search; + + ret = kobject_get(k); + goto unlock_exit; + +slow_search: list_for_each_entry(k, &kset->list, entry) { if (kobject_name(k) && !strcmp(kobject_name(k), name)) { ret = kobject_get(k); break; } } + +unlock_exit: spin_unlock(&kset->list_lock); + + if (hint) + kobject_put(hint); + return ret; } -- cgit v1.2.2