From: David Miller <davem@davemloft.net>
To: eric.dumazet@gmail.com
Cc: netdev@vger.kernel.org
Subject: Re: [PATCH net-next] l2tp: give proper headroom in pppol2tp_xmit()
Date: Tue, 18 Oct 2011 23:34:44 -0400 (EDT) [thread overview]
Message-ID: <20111018.233444.955647916101091708.davem@davemloft.net> (raw)
In-Reply-To: <1318002357.3207.28.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC>
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Fri, 07 Oct 2011 17:45:57 +0200
> pppol2tp_xmit() calls skb_cow_head(skb, 2) before calling
> l2tp_xmit_skb()
>
> Then l2tp_xmit_skb() calls again skb_cow_head(skb, large_headroom)
>
> This patchs changes the first skb_cow_head() call to supply the needed
> headroom to make sure at most one (expensive) pskb_expand_head() is
> done.
>
> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
> ---
> Maybe we should add a counter to help diagnose too many
> pskb_expand_head() calls...
Applied.
I think it's the kind of event that deserves a tracepoint, this way one
could use perf to notice and diagnose such problems.
next prev parent reply other threads:[~2011-10-19 3:34 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-07 15:45 [PATCH net-next] l2tp: give proper headroom in pppol2tp_xmit() Eric Dumazet
2011-10-19 3:34 ` David Miller [this message]
2011-10-19 4:00 ` Eric Dumazet
2011-10-19 4:12 ` David Miller
2011-10-19 4:24 ` Eric Dumazet
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