Messages in this thread | | | Date | Wed, 19 Sep 2012 10:06:48 -0700 | From | "Paul E. McKenney" <> | Subject | Re: RCU idle CPU detection is broken in linux-next |
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On Wed, Sep 19, 2012 at 06:35:36PM +0200, Sasha Levin wrote: > On 09/19/2012 05:39 PM, Paul E. McKenney wrote: > > On Wed, Sep 12, 2012 at 07:56:48PM +0200, Sasha Levin wrote: > >> > Hi Paul, > >> > > >> > While fuzzing using trinity inside a KVM tools guest, I've managed to trigger > >> > "RCU used illegally from idle CPU!" warnings several times. > >> > > >> > There are a bunch of traces which seem to pop exactly at the same time and from > >> > different places around the kernel. Here are several of them: > > Hello, Sasha, > > > > OK, interesting. Could you please try reproducing with the diagnostic > > patch shown below? > > Sure - here are the results (btw, it reproduces very easily): > > [ 13.525119] ================================================ > [ 13.527165] [ BUG: lock held when returning to user space! ] > [ 13.528752] 3.6.0-rc6-next-20120918-sasha-00002-g190c311-dirty #362 Tainted: GW > [ 13.531314] ------------------------------------------------ > [ 13.532918] init/1 is leaving the kernel with locks still held! > [ 13.534574] 1 lock held by init/1: > [ 13.535533] #0: (rcu_idle){.+.+..}, at: [<ffffffff811c36d0>] > rcu_eqs_enter_common+0x1a0/0x9a0 > > I'm basically seeing lots of the above, so I can't even get to the point where I > get the previous lockdep warnings.
OK, that diagnostic patch was unhelpful. Back to the drawing board...
Thanx, Paul
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