From: Tejun Heo <tj@kernel.org>
To: Johannes Berg <johannes@sipsolutions.net>
Cc: Ben Greear <greearb@candelatech.com>,
"linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>
Subject: Re: ath5k/mac80211: Reproducible deadlock with 64-stations.
Date: Thu, 11 Nov 2010 10:27:50 +0100 [thread overview]
Message-ID: <4CDBB716.7020802@kernel.org> (raw)
In-Reply-To: <1289437356.3748.25.camel@jlt3.sipsolutions.net>
Hello,
On 11/11/2010 02:02 AM, Johannes Berg wrote:
> 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: #2: (rtnl_mutex){+.+.+.}, at: [<c070220f>] rtnl_lock+0xf/0x11
...
>> Nov 10 14:54:33 localhost kernel: #0: (rtnl_mutex){+.+.+.}, at: [<c070220f>] rtnl_lock+0xf/0x11
...
>> Nov 10 14:54:33 localhost kernel: #2: (rtnl_mutex){+.+.+.}, at: [<c070220f>] rtnl_lock+0xf/0x11
...
>> 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
Looks like everyone is stuck trying to get hold of rtnl_mutex.
Lockdep seems enabled, isn't there a sysrq which shows all held locks?
Yeah, it's 'd'. I don't think much can be found out by looking at the
above part. We need to be looking at who's holding the lock. Is the
problem reproducible?
Thank you.
--
tejun
next prev parent reply other threads:[~2010-11-11 9:27 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
2010-11-11 9:27 ` Tejun Heo [this message]
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
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=4CDBB716.7020802@kernel.org \
--to=tj@kernel.org \
--cc=greearb@candelatech.com \
--cc=johannes@sipsolutions.net \
--cc=linux-wireless@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.