linux-kernel - Re: BUG: sleeping function called from invalid context at kernel/mutex.c:271

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 18 Apr 2012 06:51:52 -0700
From:	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
To:	Steven Rostedt <rostedt@...dmis.org>
Cc:	"Alexander E. Patrakov" <patrakov@...il.com>,
	linux-kernel@...r.kernel.org
Subject: Re: BUG: sleeping function called from invalid context at
 kernel/mutex.c:271

On Wed, Apr 18, 2012 at 08:08:46AM -0400, Steven Rostedt wrote:
> On Wed, 2012-04-18 at 10:51 +0600, Alexander E. Patrakov wrote:
> 
> > > > 
> > > > Hmm, this can also be reported if you have an rcu leak. Which would also
> > > > explain your memory leak. RCU is the kernel's "garbage collector" and if
> > > > it gets stuck, then you will definitely start seeing memory leaks, as
> > > > memory wont be freed.
> > > 
> > > If RCU is stuck, you should see RCU CPU stall warnings, which can
> > > give clues as to what is causing RCU to get stuck.
> > 
> > Yes, there were such warnings, but all of them said that the stall ended
> > before dump start. So nothing reportable here, but I have just found
> > that https://bugzilla.novell.com/show_bug.cgi?id=754186 looks quite
> > similar in the sense that it (and duplicates) also has undumpable stalls
> > of increasing length, and IPv6 is in use both at home and at work.
> > 
> 
> Do you see the RT throttling message too? That's a bug with an RT task
> going haywire. If that is happening, an RT task may be preventing an RCU
> grace period to finish, and causing the RCU stalls.

Hmmm...  Maybe I should revisit running the RCU core processing in
real-time kernel threads...  Though it was quite painful the last time
I tried that.

							Thanx, Paul

> Just because they ended, doesn't mean that the problem went a way. If
> RCU is being blocked, you will start to see memory leaks. As I said, RCU
> works as the kernels garbage collector. If it stops or just slows down
> significantly, memory does not get freed.
> 
> -- Steve
> 
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@...r.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/
> 

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/