Messages in this thread | | | Date | Fri, 26 Feb 2010 13:21:55 +0800 | From | Gui Jianfeng <> | Subject | Re: [PATCH] cfq: Remove useless css reference get |
| |
Vivek Goyal wrote: > On Wed, Dec 16, 2009 at 04:38:43PM +0800, Gui Jianfeng wrote: >> 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>
Hi Jens
Would you pick this patch up?
> > Thanks > Vivek > >> --- >> block/blk-cgroup.c | 14 -------------- >> block/blk-cgroup.h | 3 --- >> block/cfq-iosched.c | 5 ----- >> 3 files changed, 0 insertions(+), 22 deletions(-) >> >> diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c >> index 1fa2654..cba28f4 100644 >> --- a/block/blk-cgroup.c >> +++ b/block/blk-cgroup.c >> @@ -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), >> diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h >> index 4d316df..84bf745 100644 >> --- a/block/blk-cgroup.h >> +++ b/block/blk-cgroup.h >> @@ -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); >> diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c >> index e2f8046..5d6b427 100644 >> --- a/block/cfq-iosched.c >> +++ b/block/cfq-iosched.c >> @@ -958,10 +958,6 @@ 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; >> @@ -992,7 +988,6 @@ 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; >> } >> >> -- >> 1.5.4.rc3 >> > > >
| |