Messages in this thread | | | Date | Wed, 29 Nov 2006 09:44:28 +0100 | From | Jarek Poplawski <> | Subject | Re: [PATCH] lockdep: fix sk->sk_callback_lock locking |
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On 29-11-2006 08:49, Herbert Xu wrote: > Peter Zijlstra <a.p.zijlstra@chello.nl> wrote: >> ========================================================= >> [ INFO: possible irq lock inversion dependency detected ] >> 2.6.19-rc6 #4 >> --------------------------------------------------------- >> nc/1854 just changed the state of lock: >> (af_callback_keys + sk->sk_family#2){-.-?}, at: [<c0268a7f>] sock_def_error_report+0x1f/0x90 >> but this lock was taken by another, soft-irq-safe lock in the past: >> (slock-AF_INET){-+..} >> >> and interrupts could create inverse lock ordering between them. > > I think this is bogus. The slock is not a standard lock. When we > hold it in process context we don't actually hold the spin lock part > of it. However, it does prevent the softirq path from running in > critical sections which also prevents any attempt to grab the > callback lock from softirq context. > > If you still think there is a problem, please show an actual scenario > where it dead locks.
It would be nice to have a look at other parts of stack backtraces probably with softirq part, which took that lock: sk->sk_family#2){-.-?}
Jarek P. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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