This message has been generated automatically as a part of a report

of recent regressions.
The following bug entry is on the current list of known regressions

from 2.6.24.  Please verify if it still should be listed.
Bug-Entry	: http://bugzilla.kernel.org/show_bug.cgi?id=10326

Subject		: inconsistent lock state in net_rx_action

Submitter	: Marcus Better <marcus@better.se>

Date		: 2008-03-25 13:21 (15 days old)

Patch		: http://bugzilla.kernel.org/show_bug.cgi?id=10326#c20
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From: "Rafael J. Wysocki" <rjw@sisk.pl>
This is already fixed by:
commit 50fd4407b8bfbde7c1a0bfe4f24de7df37164342

Author: David S. Miller <davem@davemloft.net>

Date:   Thu Mar 27 17:42:50 2008 -0700
    [NET]: Use local_irq_{save,restore}() in napi_complete().
    Based upon a lockdep report.
    Since ->poll() can be invoked from netpoll with interrupts

    disabled, we must not unconditionally enable interrupts

    in napi_complete().
    Instead we must use local_irq_{save,restore}().
    Noticed by Peter Zijlstra:
    <irqs disabled>
      netpoll_poll()

        poll_napi()

          spin_trylock(&napi->poll_lock)

          poll_one_napi()

            napi->poll() := sky2_poll()

              napi_complete()

                local_irq_disable()

                local_irq_enable() <--- *BUG*
      <irq>

        irq_exit()

          do_softirq()

            net_rx_action()

              spin_lock(&napi->poll_lock) <--- Deadlock!
    Because we still hold the lock....
    Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h

index a2f0032..fae6a7e 100644

--- a/include/linux/netdevice.h

+++ b/include/linux/netdevice.h

@@ -383,9 +383,11 @@ static inline void __napi_complete(struct napi_struct *n)
 static inline void napi_complete(struct napi_struct *n)

 {

-	local_irq_disable();

+	unsigned long flags;

+

+	local_irq_save(flags);

 	__napi_complete(n);

-	local_irq_enable();

+	local_irq_restore(flags);

 }
 /**

--

Thanks, closed.
Rafael

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