From: Jarek Poplawski <jarkao2@gmail.com>
To: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>, netdev@vger.kernel.org
Subject: [PATCH] pkt_sched: Fix lockdep warning on est_tree_lock in gen_estimator
Date: Thu, 2 Sep 2010 22:12:58 +0200 [thread overview]
Message-ID: <20100902201257.GA3089@del.dom.local> (raw)
Hi,
Almost any tc qdisc activity on 2.6.35 or later triggers this warning
(the patch below):
[ 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.
[ 516.288386]
[ 516.288386]
[ 516.288386] other info that might help us debug this:
[ 516.288386] 2 locks held by swapper/0:
[ 516.288386] #0: (&elist[idx].timer){+.-...}, at: [<c10334b5>] run_timer_softirq+0x11d/0x263
[ 516.288386] #1: (rcu_read_lock){.+.+..}, at: [<c12eac78>] est_timer+0x0/0x1b4
[ 516.288386]
[ 516.288386] the shortest dependencies between 2nd lock and 1st lock:
[ 516.288386] -> (est_tree_lock){+.+...} ops: 5 {
[ 516.288386] HARDIRQ-ON-W at:
[ 516.288386] [<c104a421>] __lock_acquire+0x306/0xbd6
[ 516.288386] [<c104ad9d>] lock_acquire+0xac/0xc8
[ 516.288386] [<c13c53ce>] _raw_spin_lock+0x25/0x34
[ 516.288386] [<c12ea985>] gen_estimator_active+0x39/0x74
[ 516.288386] [<c12ea82a>] gnet_stats_copy_rate_est+0x16/0x4d
[ 516.288386] [<c1300000>] tc_fill_qdisc+0x186/0x1e2
[ 516.288386] [<c13001b2>] qdisc_notify+0x94/0xcf
[ 516.288386] [<c1300385>] notify_and_destroy+0x27/0x3d
[ 516.288386] [<c1300490>] qdisc_graft+0xf5/0x1c6
[ 516.288386] [<c130110a>] tc_modify_qdisc+0x369/0x3b8
[ 516.288386] [<c12f8d09>] rtnetlink_rcv_msg+0x197/0x1b1
[ 516.288386] [<c1305cc0>] netlink_rcv_skb+0x30/0x75
[ 516.288386] [<c12f8b6a>] rtnetlink_rcv+0x1e/0x26
[ 516.288386] [<c1305b01>] netlink_unicast+0xc4/0x11a
[ 516.288386] [<c13061a2>] netlink_sendmsg+0x23a/0x252
[ 516.288386] [<c12e09fd>] __sock_sendmsg+0x4d/0x56
[ 516.288386] [<c12e0e42>] sock_sendmsg+0x95/0xab
[ 516.288386] [<c12e1024>] sys_sendmsg+0x13f/0x18f
[ 516.288386] [<c12e2676>] sys_socketcall+0x155/0x1a3
[ 516.288386] [<c13c5e25>] syscall_call+0x7/0xb
[ 516.288386] SOFTIRQ-ON-W at:
[ 516.288386] [<c104a442>] __lock_acquire+0x327/0xbd6
[ 516.288386] [<c104ad9d>] lock_acquire+0xac/0xc8
[ 516.288386] [<c13c53ce>] _raw_spin_lock+0x25/0x34
[ 516.288386] [<c12ea9d8>] gen_kill_estimator+0x18/0x9b
[ 516.288386] [<c12fea48>] qdisc_destroy+0x34/0x79
[ 516.288386] [<c1300393>] notify_and_destroy+0x35/0x3d
[ 516.288386] [<c1300490>] qdisc_graft+0xf5/0x1c6
[ 516.288386] [<c1300686>] tc_get_qdisc+0x125/0x157
[ 516.288386] [<c12f8d09>] rtnetlink_rcv_msg+0x197/0x1b1
[ 516.288386] [<c1305cc0>] netlink_rcv_skb+0x30/0x75
[ 516.288386] [<c12f8b6a>] rtnetlink_rcv+0x1e/0x26
[ 516.288386] [<c1305b01>] netlink_unicast+0xc4/0x11a
[ 516.288386] [<c13061a2>] netlink_sendmsg+0x23a/0x252
[ 516.288386] [<c12e09fd>] __sock_sendmsg+0x4d/0x56
[ 516.288386] [<c12e0e42>] sock_sendmsg+0x95/0xab
[ 516.288386] [<c12e1024>] sys_sendmsg+0x13f/0x18f
[ 516.288386] [<c12e2676>] sys_socketcall+0x155/0x1a3
[ 516.288386] [<c13c5e25>] syscall_call+0x7/0xb
[ 516.288386] INITIAL USE at:
[ 516.288386] [<c104a49a>] __lock_acquire+0x37f/0xbd6
[ 516.288386] [<c104ad9d>] lock_acquire+0xac/0xc8
[ 516.288386] [<c13c53ce>] _raw_spin_lock+0x25/0x34
[ 516.288386] [<c12ea985>] gen_estimator_active+0x39/0x74
[ 516.288386] [<c12ea82a>] gnet_stats_copy_rate_est+0x16/0x4d
[ 516.288386] [<c1300000>] tc_fill_qdisc+0x186/0x1e2
[ 516.288386] [<c13001b2>] qdisc_notify+0x94/0xcf
[ 516.288386] [<c1300385>] notify_and_destroy+0x27/0x3d
[ 516.288386] [<c1300490>] qdisc_graft+0xf5/0x1c6
[ 516.288386] [<c130110a>] tc_modify_qdisc+0x369/0x3b8
[ 516.288386] [<c12f8d09>] rtnetlink_rcv_msg+0x197/0x1b1
[ 516.288386] [<c1305cc0>] netlink_rcv_skb+0x30/0x75
[ 516.288386] [<c12f8b6a>] rtnetlink_rcv+0x1e/0x26
[ 516.288386] [<c1305b01>] netlink_unicast+0xc4/0x11a
[ 516.288386] [<c13061a2>] netlink_sendmsg+0x23a/0x252
[ 516.288386] [<c12e09fd>] __sock_sendmsg+0x4d/0x56
[ 516.288386] [<c12e0e42>] sock_sendmsg+0x95/0xab
[ 516.288386] [<c12e1024>] sys_sendmsg+0x13f/0x18f
[ 516.288386] [<c12e2676>] sys_socketcall+0x155/0x1a3
[ 516.288386] [<c13c5e25>] syscall_call+0x7/0xb
[ 516.288386] }
[ 516.288386] ... key at: [<c15a70fc>] est_tree_lock+0x10/0x1c
[ 516.288386] ... acquired at:
[ 516.288386] [<c104ad9d>] lock_acquire+0xac/0xc8
[ 516.288386] [<c13c53ce>] _raw_spin_lock+0x25/0x34
[ 516.288386] [<c12ea985>] gen_estimator_active+0x39/0x74
[ 516.288386] [<c12ea82a>] gnet_stats_copy_rate_est+0x16/0x4d
[ 516.288386] [<c1300000>] tc_fill_qdisc+0x186/0x1e2
[ 516.288386] [<c13001b2>] qdisc_notify+0x94/0xcf
[ 516.288386] [<c1300385>] notify_and_destroy+0x27/0x3d
[ 516.288386] [<c1300490>] qdisc_graft+0xf5/0x1c6
[ 516.288386] [<c130110a>] tc_modify_qdisc+0x369/0x3b8
[ 516.288386] [<c12f8d09>] rtnetlink_rcv_msg+0x197/0x1b1
[ 516.288386] [<c1305cc0>] netlink_rcv_skb+0x30/0x75
[ 516.288386] [<c12f8b6a>] rtnetlink_rcv+0x1e/0x26
[ 516.288386] [<c1305b01>] netlink_unicast+0xc4/0x11a
[ 516.288386] [<c13061a2>] netlink_sendmsg+0x23a/0x252
[ 516.288386] [<c12e09fd>] __sock_sendmsg+0x4d/0x56
[ 516.288386] [<c12e0e42>] sock_sendmsg+0x95/0xab
[ 516.288386] [<c12e1024>] sys_sendmsg+0x13f/0x18f
[ 516.288386] [<c12e2676>] sys_socketcall+0x155/0x1a3
[ 516.288386] [<c13c5e25>] syscall_call+0x7/0xb
[ 516.288386]
[ 516.288386] -> (&qdisc_tx_lock){+.-...} ops: 10 {
[ 516.288386] HARDIRQ-ON-W at:
[ 516.288386] [<c104a421>] __lock_acquire+0x306/0xbd6
[ 516.288386] [<c104ad9d>] lock_acquire+0xac/0xc8
[ 516.288386] [<c13c55e1>] _raw_spin_lock_bh+0x2a/0x39
[ 516.288386] [<c12ea8f1>] gnet_stats_start_copy_compat+0x27/0x70
[ 516.288386] [<c12fffc7>] tc_fill_qdisc+0x14d/0x1e2
[ 516.288386] [<c13001b2>] qdisc_notify+0x94/0xcf
[ 516.288386] [<c1300385>] notify_and_destroy+0x27/0x3d
[ 516.288386] [<c1300490>] qdisc_graft+0xf5/0x1c6
[ 516.288386] [<c130110a>] tc_modify_qdisc+0x369/0x3b8
[ 516.288386] [<c12f8d09>] rtnetlink_rcv_msg+0x197/0x1b1
[ 516.288386] [<c1305cc0>] netlink_rcv_skb+0x30/0x75
[ 516.288386] [<c12f8b6a>] rtnetlink_rcv+0x1e/0x26
[ 516.288386] [<c1305b01>] netlink_unicast+0xc4/0x11a
[ 516.288386] [<c13061a2>] netlink_sendmsg+0x23a/0x252
[ 516.288386] [<c12e09fd>] __sock_sendmsg+0x4d/0x56
[ 516.288386] [<c12e0e42>] sock_sendmsg+0x95/0xab
[ 516.288386] [<c12e1024>] sys_sendmsg+0x13f/0x18f
[ 516.288386] [<c12e2676>] sys_socketcall+0x155/0x1a3
[ 516.288386] [<c13c5e25>] syscall_call+0x7/0xb
[ 516.288386] IN-SOFTIRQ-W at:
[ 516.288386] [<c104a3c3>] __lock_acquire+0x2a8/0xbd6
[ 516.288386] [<c104ad9d>] lock_acquire+0xac/0xc8
[ 516.288386] [<c13c53ce>] _raw_spin_lock+0x25/0x34
[ 516.288386] [<c12eacda>] est_timer+0x62/0x1b4
[ 516.288386] [<c1033536>] run_timer_softirq+0x19e/0x263
[ 516.288386] [<c102d692>] __do_softirq+0xab/0x169
[ 516.288386] [<c102d77a>] do_softirq+0x2a/0x42
[ 516.288386] [<c102d8d6>] irq_exit+0x36/0x42
[ 516.288386] [<c1014705>] smp_apic_timer_interrupt+0x66/0x71
[ 516.288386] [<c13c5fdf>] apic_timer_interrupt+0x2f/0x34
[ 516.288386] [<c1001c13>] cpu_idle+0x31/0x5a
[ 516.288386] [<c13bc316>] rest_init+0xda/0xdf
[ 516.288386] [<c15ba7c3>] start_kernel+0x2d4/0x2d9
[ 516.288386] [<c15ba09f>] i386_start_kernel+0x9f/0xa7
[ 516.288386] INITIAL USE at:
[ 516.288386] [<c104a49a>] __lock_acquire+0x37f/0xbd6
[ 516.288386] [<c104ad9d>] lock_acquire+0xac/0xc8
[ 516.288386] [<c13c55e1>] _raw_spin_lock_bh+0x2a/0x39
[ 516.288386] [<c12ea8f1>] gnet_stats_start_copy_compat+0x27/0x70
[ 516.288386] [<c12fffc7>] tc_fill_qdisc+0x14d/0x1e2
[ 516.288386] [<c13001b2>] qdisc_notify+0x94/0xcf
[ 516.288386] [<c1300385>] notify_and_destroy+0x27/0x3d
[ 516.288386] [<c1300490>] qdisc_graft+0xf5/0x1c6
[ 516.288386] [<c130110a>] tc_modify_qdisc+0x369/0x3b8
[ 516.288386] [<c12f8d09>] rtnetlink_rcv_msg+0x197/0x1b1
[ 516.288386] [<c1305cc0>] netlink_rcv_skb+0x30/0x75
[ 516.288386] [<c12f8b6a>] rtnetlink_rcv+0x1e/0x26
[ 516.288386] [<c1305b01>] netlink_unicast+0xc4/0x11a
[ 516.288386] [<c13061a2>] netlink_sendmsg+0x23a/0x252
[ 516.288386] [<c12e09fd>] __sock_sendmsg+0x4d/0x56
[ 516.288386] [<c12e0e42>] sock_sendmsg+0x95/0xab
[ 516.288386] [<c12e1024>] sys_sendmsg+0x13f/0x18f
[ 516.288386] [<c12e2676>] sys_socketcall+0x155/0x1a3
[ 516.288386] [<c13c5e25>] syscall_call+0x7/0xb
[ 516.288386] }
[ 516.288386] ... key at: [<c1b8318c>] qdisc_tx_lock+0x0/0x8
[ 516.288386] ... acquired at:
[ 516.288386] [<c1049bf3>] check_usage_forwards+0x5d/0x68
[ 516.288386] [<c1049575>] mark_lock+0x102/0x1e0
[ 516.288386] [<c104a3c3>] __lock_acquire+0x2a8/0xbd6
[ 516.288386] [<c104ad9d>] lock_acquire+0xac/0xc8
[ 516.288386] [<c13c53ce>] _raw_spin_lock+0x25/0x34
[ 516.288386] [<c12eacda>] est_timer+0x62/0x1b4
[ 516.288386] [<c1033536>] run_timer_softirq+0x19e/0x263
[ 516.288386] [<c102d692>] __do_softirq+0xab/0x169
[ 516.288386] [<c102d77a>] do_softirq+0x2a/0x42
[ 516.288386] [<c102d8d6>] irq_exit+0x36/0x42
[ 516.288386] [<c1014705>] smp_apic_timer_interrupt+0x66/0x71
[ 516.288386] [<c13c5fdf>] apic_timer_interrupt+0x2f/0x34
[ 516.288386] [<c1001c13>] cpu_idle+0x31/0x5a
[ 516.288386] [<c13bc316>] rest_init+0xda/0xdf
[ 516.288386] [<c15ba7c3>] start_kernel+0x2d4/0x2d9
[ 516.288386] [<c15ba09f>] i386_start_kernel+0x9f/0xa7
[ 516.288386]
[ 516.288386]
[ 516.288386] stack backtrace:
[ 516.288386] Pid: 0, comm: swapper Not tainted 2.6.35b #7
[ 516.288386] Call Trace:
[ 516.288386] [<c13c3a01>] ? printk+0xf/0x16
[ 516.288386] [<c1049b8b>] print_irq_inversion_bug+0xef/0xfa
[ 516.288386] [<c1049bf3>] check_usage_forwards+0x5d/0x68
[ 516.288386] [<c1049575>] mark_lock+0x102/0x1e0
[ 516.288386] [<c1049b96>] ? check_usage_forwards+0x0/0x68
[ 516.288386] [<c104a3c3>] __lock_acquire+0x2a8/0xbd6
[ 516.288386] [<c104a49a>] ? __lock_acquire+0x37f/0xbd6
[ 516.288386] [<c104ac2b>] ? __lock_acquire+0xb10/0xbd6
[ 516.288386] [<c104ad9d>] lock_acquire+0xac/0xc8
[ 516.288386] [<c12eacda>] ? est_timer+0x62/0x1b4
[ 516.288386] [<c13c53ce>] _raw_spin_lock+0x25/0x34
[ 516.288386] [<c12eacda>] ? est_timer+0x62/0x1b4
[ 516.288386] [<c12eacda>] est_timer+0x62/0x1b4
[ 516.288386] [<c10334b5>] ? run_timer_softirq+0x11d/0x263
[ 516.288386] [<c1033536>] run_timer_softirq+0x19e/0x263
[ 516.288386] [<c12eac78>] ? est_timer+0x0/0x1b4
[ 516.288386] [<c102d692>] __do_softirq+0xab/0x169
[ 516.288386] [<c102d77a>] do_softirq+0x2a/0x42
[ 516.288386] [<c102d8d6>] irq_exit+0x36/0x42
[ 516.288386] [<c1014705>] smp_apic_timer_interrupt+0x66/0x71
[ 516.288386] [<c13c5fdf>] apic_timer_interrupt+0x2f/0x34
[ 516.288386] [<c104007b>] ? create_new_namespaces+0x37/0x127
[ 516.288386] [<c1007c0b>] ? default_idle+0x46/0x65
[ 516.288386] [<c1001c13>] cpu_idle+0x31/0x5a
[ 516.288386] [<c13bc316>] rest_init+0xda/0xdf
[ 516.288386] [<c15ba7c3>] start_kernel+0x2d4/0x2d9
[ 516.288386] [<c15ba09f>] i386_start_kernel+0x9f/0xa7
----------->
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: ae638c47dc040b8def16d05dc6acdd527628f231
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
---
diff --git a/net/core/gen_estimator.c b/net/core/gen_estimator.c
index 9fbe7f7..6743146 100644
--- a/net/core/gen_estimator.c
+++ b/net/core/gen_estimator.c
@@ -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;
}
next reply other threads:[~2010-09-02 20:13 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-02 20:12 Jarek Poplawski [this message]
2010-09-02 20:22 ` [PATCH] pkt_sched: Fix lockdep warning on est_tree_lock in gen_estimator David Miller
2010-09-02 20:32 ` Eric Dumazet
2010-09-02 20:55 ` Jarek Poplawski
2010-09-03 5:26 ` Eric Dumazet
2010-09-02 20:53 ` Eric Dumazet
2010-09-02 20:59 ` David Miller
2010-09-02 21:22 ` Jarek Poplawski
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20100902201257.GA3089@del.dom.local \
--to=jarkao2@gmail.com \
--cc=davem@davemloft.net \
--cc=eric.dumazet@gmail.com \
--cc=netdev@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.