cfq-iosched: Get rid of on_st flag

It's able to check whether a CFQ group on a service tree by
checking "cfqg->rb_node". There's no need to maintain an
extra flag here.

Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index e18d316..5d0349d 100644 (file)
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -179,7 +179,6 @@ struct cfq_group {
        /* group service_tree key */
        u64 vdisktime;
        unsigned int weight;
-       bool on_st;
 
        /* number of cfqq currently on this group */
        int nr_cfqq;
@@ -863,7 +862,7 @@ cfq_group_service_tree_add(struct cfq_data *cfqd, struct cfq_group *cfqg)
        struct rb_node *n;
 
        cfqg->nr_cfqq++;
-       if (cfqg->on_st)
+       if (!RB_EMPTY_NODE(&cfqg->rb_node))
                return;
 
        /*
@@ -879,7 +878,6 @@ cfq_group_service_tree_add(struct cfq_data *cfqd, struct cfq_group *cfqg)
                cfqg->vdisktime = st->min_vdisktime;
 
        __cfq_group_service_tree_add(st, cfqg);
-       cfqg->on_st = true;
        st->total_weight += cfqg->weight;
 }
 
@@ -896,7 +894,6 @@ cfq_group_service_tree_del(struct cfq_data *cfqd, struct cfq_group *cfqg)
                return;
 
        cfq_log_cfqg(cfqd, cfqg, "del_from_rr group");
-       cfqg->on_st = false;
        st->total_weight -= cfqg->weight;
        if (!RB_EMPTY_NODE(&cfqg->rb_node))
                cfq_rb_erase(&cfqg->rb_node, st);