From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH] [PATCH] Fix deadlock in af_packet while stressing raw
 ethernet socket interface
Date: Tue, 12 Jul 2011 01:26:55 -0700 (PDT)
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=46rom: Eric Dumazet <eric.dumazet@gmail.com>
Date: Tue, 12 Jul 2011 10:23:06 +0200

> Le mardi 12 juillet 2011 =E0 00:19 -0700, David Miller a =E9crit :
>> From: Eric Dumazet <eric.dumazet@gmail.com>
>> Date: Tue, 12 Jul 2011 08:58:48 +0200
>>=20
>> > This seems a bug, but in softirq handling in your arch
>>=20
>> That's not the problem, it's the dev_queue_xmit_nit() code
>> path that interrupt is interrupting.
>=20
> Isnt it what I said ?
>=20
> Unless I am mistaken, dev_queue_xmit_nit() is called from
> dev_hard_start_xmit(), and from dev_queue_xmit(), therefore BH
> are/should_be masked. Calling do_softirq() while BH are masked is the
> bug.
>=20
> Something must be messing the !in_interrupt() test done from irq_exit=
()

Aha, I see.  Yes, this seems to be where the problem are.