netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH RFC] tcp: Do not reload skb pointer after skb_gro_receive().
@ 2018-06-12  1:00 David Miller
  2018-06-12  2:59 ` Eric Dumazet
  0 siblings, 1 reply; 2+ messages in thread
From: David Miller @ 2018-06-12  1:00 UTC (permalink / raw)
  To: netdev; +Cc: edumazet


This is not necessary.  skb_gro_receive() will never change what
'head' points to.

In it's original implementation (see commit 71d93b39e52e ("net: Add
skb_gro_receive")), it did:

====================
+	*head = nskb;
+	nskb->next = p->next;
+	p->next = NULL;
====================

This sequence was removed in commit 58025e46ea2d ("net: gro: remove
obsolete code from skb_gro_receive()")

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c
index 4d58e2ce0b5b..8cc7c3487330 100644
--- a/net/ipv4/tcp_offload.c
+++ b/net/ipv4/tcp_offload.c
@@ -268,8 +268,6 @@ struct sk_buff **tcp_gro_receive(struct sk_buff **head, struct sk_buff *skb)
 		goto out_check_final;
 	}
 
-	p = *head;
-	th2 = tcp_hdr(p);
 	tcp_flag_word(th2) |= flags & (TCP_FLAG_FIN | TCP_FLAG_PSH);
 
 out_check_final:

^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [PATCH RFC] tcp: Do not reload skb pointer after skb_gro_receive().
  2018-06-12  1:00 [PATCH RFC] tcp: Do not reload skb pointer after skb_gro_receive() David Miller
@ 2018-06-12  2:59 ` Eric Dumazet
  0 siblings, 0 replies; 2+ messages in thread
From: Eric Dumazet @ 2018-06-12  2:59 UTC (permalink / raw)
  To: David Miller, netdev; +Cc: edumazet



On 06/11/2018 06:00 PM, David Miller wrote:
> 
> This is not necessary.  skb_gro_receive() will never change what
> 'head' points to.
> 
> In it's original implementation (see commit 71d93b39e52e ("net: Add
> skb_gro_receive")), it did:
> 
> ====================
> +	*head = nskb;
> +	nskb->next = p->next;
> +	p->next = NULL;
> ====================
> 
> This sequence was removed in commit 58025e46ea2d ("net: gro: remove
> obsolete code from skb_gro_receive()")
> 
> Signed-off-by: David S. Miller <davem@davemloft.net>

SGTM, thanks David !

Signed-off-by: Eric Dumazet <edumazet@google.com>

^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2018-06-12  2:59 UTC | newest]

Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2018-06-12  1:00 [PATCH RFC] tcp: Do not reload skb pointer after skb_gro_receive() David Miller
2018-06-12  2:59 ` Eric Dumazet

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).