cfq: Remove useless css reference get

There's no need to take css reference here, for the caller
has already called rcu_read_lock() to prevent cgroup from
being removed.

Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
Gui Jianfeng 2010-02-26 08:56:15 +01:00 committed by Jens Axboe
parent 7f03292ee1
commit 024f906616
3 changed files with 0 additions and 22 deletions

View file

@ -23,20 +23,6 @@ static LIST_HEAD(blkio_list);
struct blkio_cgroup blkio_root_cgroup = { .weight = 2*BLKIO_WEIGHT_DEFAULT };
EXPORT_SYMBOL_GPL(blkio_root_cgroup);
bool blkiocg_css_tryget(struct blkio_cgroup *blkcg)
{
if (!css_tryget(&blkcg->css))
return false;
return true;
}
EXPORT_SYMBOL_GPL(blkiocg_css_tryget);
void blkiocg_css_put(struct blkio_cgroup *blkcg)
{
css_put(&blkcg->css);
}
EXPORT_SYMBOL_GPL(blkiocg_css_put);
struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup)
{
return container_of(cgroup_subsys_state(cgroup, blkio_subsys_id),

View file

@ -43,9 +43,6 @@ struct blkio_group {
unsigned long sectors;
};
extern bool blkiocg_css_tryget(struct blkio_cgroup *blkcg);
extern void blkiocg_css_put(struct blkio_cgroup *blkcg);
typedef void (blkio_unlink_group_fn) (void *key, struct blkio_group *blkg);
typedef void (blkio_update_group_weight_fn) (struct blkio_group *blkg,
unsigned int weight);

View file

@ -951,10 +951,6 @@ cfq_find_alloc_cfqg(struct cfq_data *cfqd, struct cgroup *cgroup, int create)
struct backing_dev_info *bdi = &cfqd->queue->backing_dev_info;
unsigned int major, minor;
/* Do we need to take this reference */
if (!blkiocg_css_tryget(blkcg))
return NULL;;
cfqg = cfqg_of_blkg(blkiocg_lookup_group(blkcg, key));
if (cfqg || !create)
goto done;
@ -985,7 +981,6 @@ cfq_find_alloc_cfqg(struct cfq_data *cfqd, struct cgroup *cgroup, int create)
hlist_add_head(&cfqg->cfqd_node, &cfqd->cfqg_list);
done:
blkiocg_css_put(blkcg);
return cfqg;
}