From: Johannes Berg <johannes@sipsolutions.net>
To: Ben Greear <greearb@candelatech.com>
Cc: "linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>,
Tejun Heo <tj@kernel.org>
Subject: Re: ath5k/mac80211: Reproducible deadlock with 64-stations.
Date: Wed, 10 Nov 2010 17:02:36 -0800 [thread overview]
Message-ID: <1289437356.3748.25.camel@jlt3.sipsolutions.net> (raw)
In-Reply-To: <4CDB2488.4040802@candelatech.com>
I don't really see any deadlock here... hmm. Tejun, do you see anything
wrong with the "locking" in workq stuff here?
Something is holding the RTNL, and a bunch of other things are trying to
acquire it. We don't really know who's holding it and who's acquiring it
though.
> Nov 10 14:54:33 localhost kernel: Showing all locks held in the system:
> Nov 10 14:54:33 localhost kernel: 3 locks held by kworker/0:0/4:
> Nov 10 14:54:33 localhost kernel: #0: (events){+.+.+.}, at: [<c0446ded>] process_one_work+0x13e/0x2bf
> Nov 10 14:54:33 localhost kernel: #1: ((linkwatch_work).work){+.+.+.}, at: [<c0446ded>] process_one_work+0x13e/0x2bf
> Nov 10 14:54:33 localhost kernel: #2: (rtnl_mutex){+.+.+.}, at: [<c070220f>] rtnl_lock+0xf/0x11
This comes in from schedule_work() IIRC.
> Nov 10 14:54:33 localhost kernel: 1 lock held by ntpd/1675:
> Nov 10 14:54:33 localhost kernel: #0: (rtnl_mutex){+.+.+.}, at: [<c070220f>] rtnl_lock+0xf/0x11
ntpd holding/acquiring rtnl
...
> Nov 10 14:54:33 localhost kernel: #0: (events){+.+.+.}, at: [<c0446ded>] process_one_work+0x13e/0x2bf
> Nov 10 14:54:33 localhost kernel: #1: (wireless_nlevent_work){+.+.+.}, at: [<c0446ded>] process_one_work+0x13e/0x2bf
> Nov 10 14:54:33 localhost kernel: #2: (rtnl_mutex){+.+.+.}, at: [<c070220f>] rtnl_lock+0xf/0x11
another schedule_work() acquiring/holding RTNL.
> Nov 10 14:54:33 localhost kernel: 1 lock held by ip/6438:
> Nov 10 14:54:33 localhost kernel: #0: (rtnl_mutex){+.+.+.}, at: [<c070f78c>] netlink_dump+0x3a/0x16a
> Nov 10 14:54:33 localhost kernel: 1 lock held by ip/6441:
> Nov 10 14:54:33 localhost kernel: #0: (rtnl_mutex){+.+.+.}, at: [<c070220f>] rtnl_lock+0xf/0x11
> Nov 10 14:54:33 localhost kernel: 1 lock held by ip/6442:
> Nov 10 14:54:33 localhost kernel: #0: (rtnl_mutex){+.+.+.}, at: [<c070220f>] rtnl_lock+0xf/0x11
> Nov 10 14:54:33 localhost kernel: 1 lock held by iwconfig/6443:
> Nov 10 14:54:33 localhost kernel: #0: (rtnl_mutex){+.+.+.}, at: [<c070220f>] rtnl_lock+0xf/0x11
> Nov 10 14:54:33 localhost kernel: 1 lock held by ip/6444:
> Nov 10 14:54:33 localhost kernel: #0: (rtnl_mutex){+.+.+.}, at: [<c070220f>] rtnl_lock+0xf/0x11
bunch of other things trying / holding ...
The other things I snipped seem completely orthogonal...
johannes
next prev parent reply other threads:[~2010-11-11 1:01 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-10 23:02 ath5k/mac80211: Reproducible deadlock with 64-stations Ben Greear
2010-11-11 0:57 ` Ben Greear
2010-11-11 1:03 ` Johannes Berg
2010-11-11 5:51 ` Ben Greear
2010-11-11 1:02 ` Johannes Berg [this message]
2010-11-11 9:27 ` Tejun Heo
2010-11-11 16:55 ` Ben Greear
2010-11-11 18:26 ` Ben Greear
2010-11-11 23:12 ` Ben Greear
2010-11-12 10:11 ` Tejun Heo
2010-11-12 10:15 ` Tejun Heo
2010-11-12 18:06 ` Ben Greear
2010-11-12 18:13 ` Tejun Heo
2010-11-12 18:34 ` Ben Greear
2010-11-12 17:18 ` Ben Greear
2010-11-12 0:48 ` Ben Greear
2010-11-12 2:37 ` Johannes Berg
2010-11-12 16:32 ` Ben Greear
2010-11-12 16:45 ` Johannes Berg
2010-11-12 17:37 ` Ben Greear
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