From mboxrd@z Thu Jan  1 00:00:00 1970
From: Zoltan Kiss <zoltan.kiss@citrix.com>
Subject: Re: tcp_use_frto crashes on empty tcp_write_queue
Date: Wed, 13 Feb 2013 22:14:17 +0000
Message-ID: <511C1039.9020001@citrix.com>
References: <511C0127.1040604@citrix.com> <1360791453.6884.34.camel@edumazet-glaptop>
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Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	Frediano Ziglio <frediano.ziglio@citrix.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
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Hi,

On 13/02/13 21:37, Eric Dumazet wrote:
> This doesn't seem to be a standard kernel.

Indeed, this is a XenServer 6.0.2 kernel, which contains changes, 
however the TCP parts are barely modified. The related code path were 
not changed.
I'm trying to determine if this bug could be fixed in an obvious way, so 
let me rephrase my question: if the socket write queue is empty, 
shouldn't we just stop going further instead of dropping a WARN? Or, if 
there is a reason to do so, shouldn't we check at least that returned 
pointer in tcp_use_frto()?

Regards,

Zoltan Kiss