pkt_sched: Fix lockdep warning on est_tree_lock in gen_estimator (0b5d404e) · Commits · 戴 / test

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: ("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>

net/core/gen_estimator.c

+6 −6

Original line number	Diff line number	Diff line
		@@ -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;
		}

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