From 89819dc01f4c5920783f561597a48d9d75220e9e Mon Sep 17 00:00:00 2001 From: WANG Cong Date: Sun, 15 Dec 2013 20:15:09 -0800 Subject: net_sched: convert tcf_hashinfo to hlist and use spinlock So that we don't need to play with singly linked list, and since the code is not on hot path, we can use spinlock instead of rwlock. Cc: Jamal Hadi Salim Cc: David S. Miller Signed-off-by: Cong Wang Signed-off-by: Jamal Hadi Salim Signed-off-by: David S. Miller --- net/sched/act_police.c | 45 ++++++++++++++++++--------------------------- 1 file changed, 18 insertions(+), 27 deletions(-) (limited to 'net/sched/act_police.c') diff --git a/net/sched/act_police.c b/net/sched/act_police.c index f201576d25c2..0cc305e7e469 100644 --- a/net/sched/act_police.c +++ b/net/sched/act_police.c @@ -60,18 +60,19 @@ struct tc_police_compat { static int tcf_act_police_walker(struct sk_buff *skb, struct netlink_callback *cb, int type, struct tc_action *a) { + struct hlist_head *head; struct tcf_common *p; int err = 0, index = -1, i = 0, s_i = 0, n_i = 0; struct nlattr *nest; - read_lock_bh(&police_hash_info.lock); + spin_lock_bh(&police_hash_info.lock); s_i = cb->args[0]; for (i = 0; i < (POL_TAB_MASK + 1); i++) { - p = police_hash_info.htab[tcf_hash(i, POL_TAB_MASK)]; + head = &police_hash_info.htab[tcf_hash(i, POL_TAB_MASK)]; - for (; p; p = p->tcfc_next) { + hlist_for_each_entry_rcu(p, head, tcfc_head) { index++; if (index < s_i) continue; @@ -94,7 +95,7 @@ static int tcf_act_police_walker(struct sk_buff *skb, struct netlink_callback *c } } done: - read_unlock_bh(&police_hash_info.lock); + spin_unlock_bh(&police_hash_info.lock); if (n_i) cb->args[0] += n_i; return n_i; @@ -106,25 +107,16 @@ nla_put_failure: static void tcf_police_destroy(struct tcf_police *p) { - unsigned int h = tcf_hash(p->tcf_index, POL_TAB_MASK); - struct tcf_common **p1p; - - for (p1p = &police_hash_info.htab[h]; *p1p; p1p = &(*p1p)->tcfc_next) { - if (*p1p == &p->common) { - write_lock_bh(&police_hash_info.lock); - *p1p = p->tcf_next; - write_unlock_bh(&police_hash_info.lock); - gen_kill_estimator(&p->tcf_bstats, - &p->tcf_rate_est); - /* - * gen_estimator est_timer() might access p->tcf_lock - * or bstats, wait a RCU grace period before freeing p - */ - kfree_rcu(p, tcf_rcu); - return; - } - } - WARN_ON(1); + spin_lock_bh(&police_hash_info.lock); + hlist_del(&p->tcf_head); + spin_unlock_bh(&police_hash_info.lock); + gen_kill_estimator(&p->tcf_bstats, + &p->tcf_rate_est); + /* + * gen_estimator est_timer() might access p->tcf_lock + * or bstats, wait a RCU grace period before freeing p + */ + kfree_rcu(p, tcf_rcu); } static const struct nla_policy police_policy[TCA_POLICE_MAX + 1] = { @@ -259,10 +251,9 @@ override: police->tcf_index = parm->index ? parm->index : tcf_hash_new_index(&police_idx_gen, &police_hash_info); h = tcf_hash(police->tcf_index, POL_TAB_MASK); - write_lock_bh(&police_hash_info.lock); - police->tcf_next = police_hash_info.htab[h]; - police_hash_info.htab[h] = &police->common; - write_unlock_bh(&police_hash_info.lock); + spin_lock_bh(&police_hash_info.lock); + hlist_add_head(&police->tcf_head, &police_hash_info.htab[h]); + spin_unlock_bh(&police_hash_info.lock); a->priv = police; return ret; -- cgit v1.2.3