netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: "Timo Teräs" <timo.teras@iki.fi>
To: netdev@vger.kernel.org
Cc: Herbert Xu <herbert@gondor.apana.org.au>,
	Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
	David Miller <davem@davemloft.net>
Subject: ip_gre headroom allocation
Date: Thu, 11 Jun 2009 11:22:34 +0300	[thread overview]
Message-ID: <4A30BECA.8030205@iki.fi> (raw)

I'm not entirely sure about this, but shouldn't we do something like
the below to make ip_gre allocation enough headroom for paths where
e.g. xfrm transformations take place (as a speed optimization)?

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index e62510d..eb78dd9 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -812,7 +812,7 @@ static int ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
                        tunnel->err_count = 0;
        }
 
-       max_headroom = LL_RESERVED_SPACE(tdev) + gre_hlen;
+       max_headroom = LL_RESERVED_SPACE(tdev) + gre_hlen + rt->u.dst.header_len;
 
        if (skb_headroom(skb) < max_headroom || skb_shared(skb)||
            (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {

             reply	other threads:[~2009-06-11  8:22 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-06-11  8:22 Timo Teräs [this message]
2009-06-11 10:09 ` ip_gre headroom allocation David Miller
2009-06-11 10:17   ` Timo Teräs
2009-06-11 10:56     ` Herbert Xu
2009-06-11 11:29       ` Timo Teräs
2009-06-11 11:37         ` Herbert Xu
2009-06-11 11:51           ` Timo Teräs
2009-06-11 12:12             ` Herbert Xu

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4A30BECA.8030205@iki.fi \
    --to=timo.teras@iki.fi \
    --cc=davem@davemloft.net \
    --cc=herbert@gondor.apana.org.au \
    --cc=kuznet@ms2.inr.ac.ru \
    --cc=netdev@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).