diff options
author | Robin Holt <holt@sgi.com> | 2010-09-29 21:00:54 +0200 |
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committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-10-22 19:16:44 +0200 |
commit | c25d1dfbd403209025df41a737f82ce8f43d93f5 (patch) | |
tree | 35110a432101ff146bae3656137d9ba6f37b38fd /lib/kobject.c | |
parent | driver core: fix build for CONFIG_BLOCK not enabled (diff) | |
download | linux-c25d1dfbd403209025df41a737f82ce8f43d93f5.tar.xz linux-c25d1dfbd403209025df41a737f82ce8f43d93f5.zip |
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 <holt@sgi.com>
To: Robert P. J. Day <rpjday@crashcourse.ca>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'lib/kobject.c')
-rw-r--r-- | lib/kobject.c | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/lib/kobject.c b/lib/kobject.c index f07c57252e82..82dc34c095c2 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -746,17 +746,56 @@ void kset_unregister(struct kset *k) */ 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; } |