[NET_SCHED] protect action config/dump from irqs
(with no apologies to C Heston) On Mon, 2007-10-09 at 21:00 +0800, Herbert Xu wrote: On Sun, Sep 02, 2007 at 01:11:29PM +0000, Christian Kujau wrote: > > > > after upgrading to 2.6.23-rc5 (and applying davem's fix [0]), lockdep > > was quite noisy when I tried to shape my external (wireless) interface: > > > > [ 6400.534545] FahCore_78.exe/3552 just changed the state of lock: > > [ 6400.534713] (&dev->ingress_lock){-+..}, at: [<c038d595>] > > netif_receive_skb+0x2d5/0x3c0 > > [ 6400.534941] but this lock took another, soft-read-irq-unsafe lock in the > > past: > > [ 6400.535145] (police_lock){-.--} > > This is a genuine dead-lock. The police lock can be taken > for reading with softirqs on. If a second CPU tries to take > the police lock for writing, while holding the ingress lock, > then a softirq on the first CPU can dead-lock when it tries > to get the ingress lock. Signed-off-by: NJamal Hadi Salim <hadi@cyberus.ca> Acked-by: NHerbert Xu <herbert@gondor.apana.org.au> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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