From: Gao feng <gaofeng@cn.fujitsu.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Miller <davem@davemloft.net>,
netdev <netdev@vger.kernel.org>,
Tom Herbert <therbert@google.com>,
Mahesh Bandewar <maheshb@google.com>,
"Eric W. Biederman" <ebiederm@xmission.com>
Subject: Re: [PATCH net-next v2] net: remove delay at device dismantle
Date: Thu, 23 Aug 2012 10:25:00 +0800 [thread overview]
Message-ID: <5035947C.8090609@cn.fujitsu.com> (raw)
In-Reply-To: <1344664487.5158.1.camel@edumazet-glaptop>
于 2012年08月11日 13:54, Eric Dumazet 写道:
> On Fri, 2012-08-10 at 17:42 +0200, Eric Dumazet wrote:
>> From: Eric Dumazet <edumazet@google.com>
>>
>> I noticed extra one second delay in device dismantle, tracked down to
>> a call to dst_dev_event() while some call_rcu() are still in RCU queues.
>>
> ...
>> Signed-off-by: Eric Dumazet <edumazet@google.com>
>> Cc: Tom Herbert <therbert@google.com>
>> Cc: Mahesh Bandewar <maheshb@google.com>
>> Cc: "Eric W. Biederman" <ebiederm@xmission.com>
>> ---
>> v2: NETDEV_UNREGISTER_FINAL called outside of rtnl lock
>> as its more risky, base this patch on net-next
>
> Also I am leaving for a one week vacation with no access to the
> Internet, so better hold this patch until my return ;)
>
Hi Eric
I got this warning message with your patch applied.
Aug 22 18:32:56 Donkey kernel: [ 124.733048] ===============================
Aug 22 18:32:56 Donkey kernel: [ 124.733051] [ INFO: suspicious RCU usage. ]
Aug 22 18:32:56 Donkey kernel: [ 124.733054] 3.6.0-rc1+ #14 Not tainted
Aug 22 18:32:56 Donkey kernel: [ 124.733057] -------------------------------
Aug 22 18:32:56 Donkey kernel: [ 124.733060] include/linux/inetdevice.h:229 suspicious rcu_dereference_protected() usage!
Aug 22 18:32:56 Donkey kernel: [ 124.733062]
Aug 22 18:32:56 Donkey kernel: [ 124.733062] other info that might help us debug this:
Aug 22 18:32:56 Donkey kernel: [ 124.733062]
Aug 22 18:32:56 Donkey kernel: [ 124.733066]
Aug 22 18:32:56 Donkey kernel: [ 124.733066] rcu_scheduler_active = 1, debug_locks = 1
Aug 22 18:32:56 Donkey kernel: [ 124.733069] 3 locks held by kworker/u:1/39:
Aug 22 18:32:56 Donkey kernel: [ 124.733072] #0: (netns){.+.+.+}, at: [<ffffffff8107e117>] process_one_work+0x137/0x5d0
Aug 22 18:32:56 Donkey kernel: [ 124.733086] #1: (net_cleanup_work){+.+.+.}, at: [<ffffffff8107e117>] process_one_work+0x137/0x5d0
Aug 22 18:32:56 Donkey kernel: [ 124.733095] #2: (net_mutex){+.+.+.}, at: [<ffffffff81542fd5>] cleanup_net+0x85/0x1a0
Aug 22 18:32:56 Donkey kernel: [ 124.733106]
Aug 22 18:32:56 Donkey kernel: [ 124.733106] stack backtrace:
Aug 22 18:32:56 Donkey kernel: [ 124.733110] Pid: 39, comm: kworker/u:1 Not tainted 3.6.0-rc1+ #14
Aug 22 18:32:56 Donkey kernel: [ 124.733112] Call Trace:
Aug 22 18:32:56 Donkey kernel: [ 124.733120] [<ffffffff810c2312>] lockdep_rcu_suspicious+0xe2/0x130
Aug 22 18:32:56 Donkey kernel: [ 124.733127] [<ffffffff815d35d4>] fib_netdev_event+0x114/0x180
Aug 22 18:32:56 Donkey kernel: [ 124.733133] [<ffffffff816914cc>] notifier_call_chain+0x5c/0x120
Aug 22 18:32:56 Donkey kernel: [ 124.733139] [<ffffffff8108d6b6>] raw_notifier_call_chain+0x16/0x20
Aug 22 18:32:56 Donkey kernel: [ 124.733144] [<ffffffff8154585c>] call_netdevice_notifiers+0x3c/0x70
Aug 22 18:32:56 Donkey kernel: [ 124.733149] [<ffffffff8154f88c>] netdev_run_todo+0x8c/0x280
Aug 22 18:32:56 Donkey kernel: [ 124.733154] [<ffffffff81544c9d>] ? synchronize_net+0x2d/0x40
Aug 22 18:32:56 Donkey kernel: [ 124.733159] [<ffffffff8155b90e>] rtnl_unlock+0xe/0x10
Aug 22 18:32:56 Donkey kernel: [ 124.733164] [<ffffffff81546c1a>] default_device_exit_batch+0xba/0xd0
Aug 22 18:32:56 Donkey kernel: [ 124.733170] [<ffffffff81542275>] ops_exit_list+0x55/0x60
Aug 22 18:32:56 Donkey kernel: [ 124.733175] [<ffffffff8154304b>] cleanup_net+0xfb/0x1a0
Aug 22 18:32:56 Donkey kernel: [ 124.733180] [<ffffffff8107e178>] process_one_work+0x198/0x5d0
Aug 22 18:32:56 Donkey kernel: [ 124.733185] [<ffffffff8107e117>] ? process_one_work+0x137/0x5d0
Aug 22 18:32:56 Donkey kernel: [ 124.733191] [<ffffffff8168b2b8>] ? __schedule+0x428/0x910
Aug 22 18:32:56 Donkey kernel: [ 124.733196] [<ffffffff81080951>] ? worker_thread+0x2a1/0x4b0
Aug 22 18:32:56 Donkey kernel: [ 124.733201] [<ffffffff81542f50>] ? net_drop_ns+0x50/0x50
Aug 22 18:32:56 Donkey kernel: [ 124.733207] [<ffffffff8108083a>] worker_thread+0x18a/0x4b0
Aug 22 18:32:56 Donkey kernel: [ 124.733212] [<ffffffff810806b0>] ? manage_workers+0x2a0/0x2a0
Aug 22 18:32:56 Donkey kernel: [ 124.733217] [<ffffffff810867de>] kthread+0xae/0xc0
Aug 22 18:32:56 Donkey kernel: [ 124.733222] [<ffffffff810c39cd>] ? trace_hardirqs_on+0xd/0x10
Aug 22 18:32:56 Donkey kernel: [ 124.733227] [<ffffffff81697044>] kernel_thread_helper+0x4/0x10
Aug 22 18:32:56 Donkey kernel: [ 124.733233] [<ffffffff8168d570>] ? retint_restore_args+0x13/0x13
Aug 22 18:32:56 Donkey kernel: [ 124.733237] [<ffffffff81086730>] ? flush_kthread_work+0x1a0/0x1a0
Aug 22 18:32:56 Donkey kernel: [ 124.733242] [<ffffffff81697040>] ? gs_change+0x13/0x13
Aug 22 18:32:56 Donkey kernel: [ 124.733248]
Aug 22 18:32:56 Donkey kernel: [ 124.733250] ===============================
next prev parent reply other threads:[~2012-08-23 2:24 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-10 9:27 [RFC] NETDEV_UNREGISTER_BATCH seems unused nowaday ? Eric Dumazet
2012-08-10 10:42 ` David Miller
2012-08-10 11:06 ` Eric Dumazet
2012-08-10 14:45 ` Eric W. Biederman
2012-08-10 15:01 ` Eric Dumazet
2012-08-10 17:55 ` Paul E. McKenney
2012-08-10 14:46 ` [PATCH] net: remove delay at device dismantle Eric Dumazet
2012-08-10 15:42 ` [PATCH net-next v2] " Eric Dumazet
2012-08-11 5:54 ` Eric Dumazet
2012-08-11 5:57 ` David Miller
2012-08-23 2:18 ` David Miller
2012-08-23 2:25 ` Gao feng [this message]
2012-08-23 2:51 ` David Miller
2012-08-23 2:58 ` Eric Dumazet
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