From 806a837650501f5eee359a197824db8752fa6e6c Mon Sep 17 00:00:00 2001 From: Gao Feng Date: Fri, 17 Feb 2017 14:34:19 +0800 Subject: [PATCH] pkt_sched: Remove useless qdisc_stab_lock The qdisc_stab_lock is used in qdisc_get_stab and qdisc_put_stab. These two functions are invoked in qdisc_create, qdisc_change, and qdisc_destroy which run fully under RTNL. So it already makes sure only one could access the qdisc_stab_list at the same time. Then it is unnecessary to use qdisc_stab_lock now. Signed-off-by: Gao Feng Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- net/sched/sch_api.c | 12 ------------ 1 file changed, 12 deletions(-) diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c index a13c15e8f087..bcf49cd22786 100644 --- a/net/sched/sch_api.c +++ b/net/sched/sch_api.c @@ -440,7 +440,6 @@ void qdisc_put_rtab(struct qdisc_rate_table *tab) EXPORT_SYMBOL(qdisc_put_rtab); static LIST_HEAD(qdisc_stab_list); -static DEFINE_SPINLOCK(qdisc_stab_lock); static const struct nla_policy stab_policy[TCA_STAB_MAX + 1] = { [TCA_STAB_BASE] = { .len = sizeof(struct tc_sizespec) }, @@ -474,20 +473,15 @@ static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt) if (tsize != s->tsize || (!tab && tsize > 0)) return ERR_PTR(-EINVAL); - spin_lock(&qdisc_stab_lock); - list_for_each_entry(stab, &qdisc_stab_list, list) { if (memcmp(&stab->szopts, s, sizeof(*s))) continue; if (tsize > 0 && memcmp(stab->data, tab, tsize * sizeof(u16))) continue; stab->refcnt++; - spin_unlock(&qdisc_stab_lock); return stab; } - spin_unlock(&qdisc_stab_lock); - stab = kmalloc(sizeof(*stab) + tsize * sizeof(u16), GFP_KERNEL); if (!stab) return ERR_PTR(-ENOMEM); @@ -497,9 +491,7 @@ static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt) if (tsize > 0) memcpy(stab->data, tab, tsize * sizeof(u16)); - spin_lock(&qdisc_stab_lock); list_add_tail(&stab->list, &qdisc_stab_list); - spin_unlock(&qdisc_stab_lock); return stab; } @@ -514,14 +506,10 @@ void qdisc_put_stab(struct qdisc_size_table *tab) if (!tab) return; - spin_lock(&qdisc_stab_lock); - if (--tab->refcnt == 0) { list_del(&tab->list); call_rcu_bh(&tab->rcu, stab_kfree_rcu); } - - spin_unlock(&qdisc_stab_lock); } EXPORT_SYMBOL(qdisc_put_stab); -- 2.30.2