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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).