Commit 90ba9b19 authored Jun 03, 2012 by Eric Dumazet Committed by David S. Miller Jun 04, 2012

tcp: tcp_make_synack() can use alloc_skb()



There is no value using sock_wmalloc() in tcp_make_synack().

A listener socket only sends SYNACK packets, they are not queued in a
socket queue, only in Qdisc and device layers, so the number of in
flight packets is limited in these layers. We used sock_wmalloc() with
the %force parameter set to 1 to ignore socket limits anyway.

This patch removes two atomic operations per SYNACK packet.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent f8f5701b

net/ipv4/tcp_output.c

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -2461,7 +2461,7 @@ struct sk_buff tcp_make_synack(struct sock sk, struct dst_entry *dst,

	if (cvp != NULL && cvp->s_data_constant && cvp->s_data_desired)		if (cvp != NULL && cvp->s_data_constant && cvp->s_data_desired)
	s_data_desired = cvp->s_data_desired;		s_data_desired = cvp->s_data_desired;
	skb = sock_wmalloc(sk, MAX_TCP_HEADER + 15 + s_data_desired, 1, GFP_ATOMIC);		skb = alloc_skb(MAX_TCP_HEADER + 15 + s_data_desired, GFP_ATOMIC);
	if (skb == NULL)		if (skb == NULL)
	return NULL;		return NULL;