pkt_sched: Fix lockdep warning on est_tree_lock in gen_estimator

This patch fixes a lockdep warning:

[  516.287584] =========================================================
[  516.288386] [ INFO: possible irq lock inversion dependency detected ]
[  516.288386] 2.6.35b #7
[  516.288386] ---------------------------------------------------------
[  516.288386] swapper/0 just changed the state of lock:
[  516.288386]  (&qdisc_tx_lock){+.-...}, at: [<c12eacda>] est_timer+0x62/0x1b4
[  516.288386] but this lock took another, SOFTIRQ-unsafe lock in the past:
[  516.288386]  (est_tree_lock){+.+...}
[  516.288386] 
[  516.288386] and interrupts could create inverse lock ordering between them.
...

So, est_tree_lock needs BH protection because it's taken by
qdisc_tx_lock, which is used both in BH and process contexts.
(Full warning with this patch at netdev, 02 Sep 2010.)

Fixes commit: ae638c47dc
("pkt_sched: gen_estimator: add a new lock")

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jarek Poplawski 2010-09-02 13:22:11 -07:00 коммит произвёл David S. Miller
Родитель 7bcbf81a22
Коммит 0b5d404e34
1 изменённых файлов: 6 добавлений и 6 удалений

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@ -232,7 +232,7 @@ int gen_new_estimator(struct gnet_stats_basic_packed *bstats,
est->last_packets = bstats->packets;
est->avpps = rate_est->pps<<10;
spin_lock(&est_tree_lock);
spin_lock_bh(&est_tree_lock);
if (!elist[idx].timer.function) {
INIT_LIST_HEAD(&elist[idx].list);
setup_timer(&elist[idx].timer, est_timer, idx);
@ -243,7 +243,7 @@ int gen_new_estimator(struct gnet_stats_basic_packed *bstats,
list_add_rcu(&est->list, &elist[idx].list);
gen_add_node(est);
spin_unlock(&est_tree_lock);
spin_unlock_bh(&est_tree_lock);
return 0;
}
@ -270,7 +270,7 @@ void gen_kill_estimator(struct gnet_stats_basic_packed *bstats,
{
struct gen_estimator *e;
spin_lock(&est_tree_lock);
spin_lock_bh(&est_tree_lock);
while ((e = gen_find_node(bstats, rate_est))) {
rb_erase(&e->node, &est_root);
@ -281,7 +281,7 @@ void gen_kill_estimator(struct gnet_stats_basic_packed *bstats,
list_del_rcu(&e->list);
call_rcu(&e->e_rcu, __gen_kill_estimator);
}
spin_unlock(&est_tree_lock);
spin_unlock_bh(&est_tree_lock);
}
EXPORT_SYMBOL(gen_kill_estimator);
@ -320,9 +320,9 @@ bool gen_estimator_active(const struct gnet_stats_basic_packed *bstats,
ASSERT_RTNL();
spin_lock(&est_tree_lock);
spin_lock_bh(&est_tree_lock);
res = gen_find_node(bstats, rate_est) != NULL;
spin_unlock(&est_tree_lock);
spin_unlock_bh(&est_tree_lock);
return res;
}