From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jesper Dangaard Brouer <brouer@redhat.com>
Subject: Re: [PATCH v2 net-next] tcp: avoid tx starvation by SYNACK packets
Date: Wed, 27 Jun 2012 11:23:34 +0200
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Cc: David Miller <davem@davemloft.net>, hans.schillstrom@ericsson.com,
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To: Eric Dumazet <eric.dumazet@gmail.com>
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On Wed, 2012-06-27 at 10:45 +0200, Eric Dumazet wrote:
> On Wed, 2012-06-27 at 10:21 +0200, Jesper Dangaard Brouer wrote:
> 
> > It works because we have a spinlock problem in the code... Perhaps, they
> > did it, because we have have locking/contention problem, not the other
> > way around ;-)  How about fixing the code instead? ;-)))
> 
> The socket lock is currently mandatory.
>
> It's really _hard_ to remove it, your attempts added a lot of races.

Yes, its really hard to remove completely.  That's why I choose _only_
to handle the SYN cookie "overload" case, and leave the rest locked, and
I also introduced extra locking in the latest patches.  I know it was
not perfect, hence the RFC tag, but I hope I didn't add that many races.


> I want to do it properly, adding needed RCU and array of spinlocks were
> appropriate.

I really appreciate that you will attempt to fix this properly.  Like a
real network ninja ;-).