From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: Major network performance regression in 3.7
Date: Sun, 06 Jan 2013 10:43:29 -0800
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Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org
To: Willy Tarreau <w@1wt.eu>
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On Sun, 2013-01-06 at 10:39 -0800, Eric Dumazet wrote:
> On Sun, 2013-01-06 at 18:35 +0100, Willy Tarreau wrote:
> 
> > Unfortunately it does not work any better, which means to me
> > that we don't leave via this code path. I tried other tricks
> > which failed too. I need to understand this part better before
> > randomly fiddling with it.
> > 
> 
> OK, now I have your test program, I can work on a fix, dont worry ;)
> 
> The MSG_SENDPAGE_NOTLAST logic needs to be tweaked.
> 


(sd->len is usually 4096, which is expected, but sd->total_len value is
huge in your case, so we always set the flag in fs/splice.c)